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Gary Eickmeier Gary Eickmeier is offline
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Default The Problem with Stereo

THE PROBLEM WITH STEREO



I want to take you on a time travel trip to an alternate present, a present
in which even more mistakes are made than have been made now, in 2016. What
mistakes? Ride with me:



Suppose that architectural acousticians were even slower than audio
engineers in catching on to what causes good sound. We go into a new concert
hall that they are designing and observe them treating the walls for great
sound. They reason that what we need to hear is just the direct sound from
the instruments because anything else bouncing off the walls all over the
place would muddy things up and dilute the imaging and everything else. They
line the front wall, the one behind the players, with Sonex or similar, to
keep the reflected sound from coming back to the audience. Similarly with
the side walls, sound absorbing materials all over the place - especially
those first reflection points, so that it will, after all, sound just as
good as our stereo recordings of them.



TROUBLEMAKERS



Things would have stayed that way except that a few troublemakers had gone
to Europe and listened in some halls that had not been treated. The sound
had a certain "spaciousness" or width to it, seeming to come from much wider
than the orchestra itself. And the tonality of the instruments! They didn't
realize that the violins and cellos had such a warmth and musicality to
them. And the percussion! It sounded a lot more important there, with all
of those reflections. The team came back and reported to the American
acousticians that maybe we DO need to hear all of those reflections that we
have been dampening and controlling. Reluctantly, the acousticians try it,
taking down all of the sound killing materials until we once again get back
to the way we know it today.



In the concert halls, anyway.



STEREO



I get it now, said one acoustician. What we should be doing is building
sound fields within the concert hall, not just the direct sound from the
instruments. If we could label these fields, we could call them the direct
sound, the early reflections, and the full reverberant field. This is all
really quite important and just the opposite of what we had been doing. Now
we can hear the full sound power put out by the instruments in all
directions, and the sound doesn't trail off so abruptly as you go back in
the hall. This is what we should have been doing all along - building sound
fields, rather than just the direct sound for the audience's ears.



"But what about stereo reproduction?" one of them asked. Our current
practice is just the direct sound from the speakers, with all reflected
energy dampened away with Sonex or clever room shapes. We have been told to
make "reflection free zones" for the primary direct sound and don't let
anything get past those first reflection points. "But this is just the
opposite from what we have learned about the concert halls" blurts one
acoustician.



Maybe we should think about this.



Yes - this principle has proven very important for the production of music,
but what about the reproduction? Why would it be any different?



Oh, that's easy. According to time honored principles, we have already
recorded those qualities of the concert hall that make good sound. Now all
we need to do is play it back and we will hear it.



Are you saying that our ears work differently for stereo than they do for
live music? The huge, complex set of direct and reflected sound fields for
live music sounds the same as the two high direct fields from two points in
space for stereo?



Well, yes, at least for the area between the speakers.



That's the best thinking for stereo reproduction today? We have just
discovered that the most important factor in the concert hall is the
building of the various sound fields within the room, but in stereo we're
going to use just the direct sound from two speakers? These two could not
sound the same.



Maybe someone from our discipline should get with the audio engineers and
explain about the spatial nature of sound - that it is very audible and must
be addressed in the reproduction just as it is for live sound or it will
sound different. That is, if they are really interested in reproducing all
characteristics of live sound.



Gary Eickmeier

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Robert Peirce Robert Peirce is offline
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Default The Problem with Stereo

The purpose of treating the listening room is to better hear the sound
field of the recording. If your room is untreated it adds its own
reflections. If the recording is bad it probably doesn't matter.
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Gary Eickmeier Gary Eickmeier is offline
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Default The Problem with Stereo

"Robert Peirce" wrote in message
...
The purpose of treating the listening room is to better hear the sound
field of the recording. If your room is untreated it adds its own
reflections. If the recording is bad it probably doesn't matter.


The sound FIELDS of the recording - the wide, spacious, set of direct and
early reflected and reverberant FIELDS -

cannot be reproduced

with just the DIRECT FIELD

from a pair of stereo speakers.

All of the direct, early reflected, and reverberant fields of the original
would be compressed into arriving from just those two points in space, not
from the original directions of the sounds that were recorded. This is very
audible.

That is the problem with stereo.

Gary Eickmeier

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Default The Problem with Stereo

On Saturday, June 25, 2016 at 4:38:20 AM UTC-7, Gary Eickmeier wrote:
THE PROBLEM WITH STEREO

at least one set of golden ears [Gordon Holt] said that he in a very real s=
ense "heard stereo" for the first time when he experimented with extracting=
the l-r and r-l signals and sending them to rear speakers with a small tim=
e delay and moderate treble roll-off, and sending the l+r signal to another=
speaker in the center between the conventional stereo pair. I have heard t=
his improvement for myself and heartily concur with Holt on this. the only =
difference is that I find the sound field to be more cohesive ["wraparound"=
] without the time delay. this also has the effect of greatly enlarging the=
"sweet spot" or at least making the usual lateral collapse of sound to the=
nearest speaker much less obnoxious, especially if the front stereo pair a=
re toed-in.
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Gary Eickmeier Gary Eickmeier is offline
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Default The Problem with Stereo

wrote:
On Saturday, June 25, 2016 at 4:38:20 AM UTC-7, Gary Eickmeier wrote:
THE PROBLEM WITH STEREO

at least one set of golden ears [Gordon Holt] said that he in a very
real sense "heard stereo" for the first time when he experimented
with extracting the l-r and r-l signals and sending them to rear
speakers with a small time delay and moderate treble roll-off, and
sending the l+r signal to another speaker in the center between the
conventional stereo pair. I have heard this improvement for myself
and heartily concur with Holt on this. the only difference is that I
find the sound field to be more cohesive ["wraparound"] without the
time delay. this also has the effect of greatly enlarging the "sweet
spot" or at least making the usual lateral collapse of sound to the
nearest speaker much less obnoxious, especially if the front stereo
pair are toed-in.


Well, obviously amen to that. But what I am saying is that stereo as most of
us apply the term today is still a half-baked concept. We have the summing
localization from left to right down pat, but that is not all there is to
it. See, first we had mono and we never expected it to make the music sound
"real" as if the musicians were right there in our room or we were right
there at the concert. Then stereo recordings and sources came around and we
just took two mono speakers and arrayed them left to right and assumed that
that was all there was to it. The implicit assumption of how it works seemed
to be you relay the sound from each microphone to your ears as accurately as
possible with no disortion or interference from the room acoustics and
voila, realism. Recording engineers go to extra lengths to construct
reflection free zones near the speakers so that they get only the pure
direct sound to their ears as the first arrival, and that is stereo.

Well, OK, first, it is true that we will never achieve the absolute realism
of transporting us to the concert hall, because of the fundamental recording
problem, that we have to run the sound through two rooms before we hear it.
In other words, we must hear our room or acoustical situation superimposed
onto the recorded sound. And no, listening anechoically doesn't work because
the sound fields do not sound natural and the imaging will not externalize
(In Head Localization, or IHL).

But we can get closer if we understand basic acoustics and that stereo on
speakers is a field-type system, not a binaural system. Once your ears are
free to hear all sounds in front of them, with no crosstalk cancellation,
then it is a field type system and we must physically reconstruct the sound
fields within our listening rooms to mimic the spatial "shape" of typical
live sound. It has not (dare I say never?) been considered before that the
reconstruction of all fields needs to be a basic part of stereo theory. What
we need to do is position the speakers in a certain way and then cast a
certain amount of direct sound toward the listening end of the room, and a
slightly greater amount of reflected sound toward the front and side walls
of the room in the same way (spatial "shape") as it happens live. You now
have a reconstruction of the live sound that is capable of decoding the
direct and reflected sounds that were recorded by means of time of arrival.
You will get the spaciousness and depth that sound more like live because of
a simple image shift toward the reflecting surfaces, giving great depth and
a soundstage from wall to wall, rather than speaker to speaker. The speakers
will disappear as sources of the sound, and you will perceive a very live
sounding Auditory Scene, or AS, in front of you. Add some surround sound to
complete the reconstruction and you have the best that can be done with
legacy stereo recordings.

The bigger the room the better because larger rooms are more the size of the
real thing, and I use specular reflectivity on the front and near side walls
to get the sharpest focus to the early reflected sound. No sound killing and
no diffusion up front. Most of these techniques are just the opposite of
what we have been assuming all these years and would never occur to audio
engineers to try.

Gary Eickmeier



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Peter Wieck Peter Wieck is offline
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Default The Problem with Stereo

On Sunday, June 26, 2016 at 6:26:02 AM UTC-4, wrote:

at least one set of golden ears [Gordon Holt] said that he in a very real=

sense "heard stereo" for the first time when he experimented with extracti=
ng the l-r and r-l signals and sending them to rear speakers with a small t=
ime delay and moderate treble roll-off, and sending the l+r signal to anoth=
er speaker in the center between the conventional stereo pair. SNIPPAGE=


This is a very old solution, AKA the "Hafler Circuit" in its early manifest=
ations, and the Advent 500 Sound Space Control and/or ADS Ambient Control C=
enter in its more complex stages.=20

I have owned all three, and still maintain the Advent 500 and the Dynaco Qu=
adAdaptor as well as one Dynaco SCA80Q. The ADS and Advent units add a digi=
tal delay that may be controlled from a "small room" to more-or-less Yankee=
Stadium, which was then taken to rear speakers via a separate amplifier, w=
ith the volume-control within the Advent. The SCA80Q used passive sum/diffe=
rence circuitry to make a similar effect, the ADS Acoustic Dimension Device=
was similar to the Advent but with an on-board power-amp and slightly less=
sophisticated controls. Back in the day when the ADS unit sold for $500, t=
he Advent for $350, the Dynaco device sold for $19.=20

As to reproducing the concert hall "at home" - not possible excepting perha=
ps somewhat with headphones. Keep in mind that EARS - such as many of us ha=
ve in some quantity *between* -1 and 3 are typically deployed in pairs sepa=
rated by a few inches of jelly and bone. What they discern is a mix of many=
things all-at-the-same-time, and rely on a very sophisticated but not very=
learned wet-ware system to make sense of the incoming noise and winnow the=
desired noise from the general mass of it. In a concert hall, that is all =
well enough. There is not much between the various noises and the EARS, so =
that if the wet-ware discerns well, and finds the result pleasing, it becom=
es 'music'. Not a hard concept.=20

Consider the average listening room - AVERAGE, not dedicated-by-a-fanatic. =
It is a mix of surfaces, and includes a mix of reproducers driven by some l=
evel of electronics. The reproducers may be from a few square inches of sur=
face reinforced by clever horns and baffles (full-range single-driver horns=
) driven by fly-powered triode amplifiers of a few watt, up to several squa=
re feet of surface driven by brute-force amplifiers of a few hundred watts.=
NONE of them have the capacity to reproduce a symphony orchestra at anythi=
ng like realistic volumes as consider the total vibrating surface area of a=
n orchestra in Tutti - or a single 30' bombard pipe. Not even close.=20

So, we try to get to some pleasing noise that is close-enough to actual mus=
ic as not to drive us instantly from the room screaming in pain. Some try b=
y means of a listening room engineered to a fare-thee-well with a sweet-spo=
t about as big in cubic area as the average head. Makes for acutely uncomfo=
rtable listening, but can be nearly-headphones enough to be more accurate t=
han the alternative. Others try for a general listening area that is clean =
enough to allow for a much more general listening location (I am of this sc=
hool) and try for enough headroom (power) and speaker range (flat frequenc=
y response) so as to get most of the original signal into the room.=20

And, of course, we have not even begun to discuss the many hundreds of peri=
pheral decisions made between the performance and the replay - engineering,=
microphone placement, mixing, equalization and much more.=20

I am not beginning to suggest or imply that it is a crap-shoot. But for dam=
ned sure, it is not neurosurgery or even rocket science. What it is, is a c=
onstantly moving target being fired on with a .22 pistol with a loose barre=
l. One might hit on occasion, but that is not to be counted on as the norm.=
=20

Again, we try to make pleasing noises using what is available to us. Theory=
allows us to speculate on what might be based on what we see and expect. B=
ut the actual practice is terribly inconvenient. "Stereo" is merely one of =
many means that have a checkered history of providing pleasing noise - some=
times.=20

I guess this is why I have five (5) active stereos in operation, and speake=
rs from Maggies to AR3as and some others between, from tube to solid-state,=
and include vinyl, RtR, cassette and CD options (as well as tuners, of cou=
rse). All of them, I have managed to bring to a pleasing state, few by the =
same measures.=20

But, the problem with STEREO is that it is not LIVE MUSIC. The expectations=
of getting the latter from the former is a contradiction-in-terms. And as =
such leads either to madness or frustration.=20

Peter Wieck
Melrose Park, PA

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Gary Eickmeier Gary Eickmeier is offline
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Default The Problem with Stereo

Peter Wieck wrote:
On Sunday, June 26, 2016 at 6:26:02 AM UTC-4,
wrote:

at least one set of golden ears [Gordon Holt] said that he in a very
real sense "heard stereo" for the first time when he experimented
with extracting the l-r and r-l signals and sending them to rear
speakers with a small time delay and moderate treble roll-off, and
sending the l+r signal to another speaker in the center between the
conventional stereo pair. SNIPPAGE


This is a very old solution, AKA the "Hafler Circuit" in its early
manifestations, and the Advent 500 Sound Space Control and/or ADS
Ambient Control Center in its more complex stages.

I have owned all three, and still maintain the Advent 500 and the
Dynaco QuadAdaptor as well as one Dynaco SCA80Q. The ADS and Advent
units add a digital delay that may be controlled from a "small room"
to more-or-less Yankee Stadium, which was then taken to rear speakers
via a separate amplifier, with the volume-control within the Advent.
The SCA80Q used passive sum/difference circuitry to make a similar
effect, the ADS Acoustic Dimension Device was similar to the Advent
but with an on-board power-amp and slightly less sophisticated
controls. Back in the day when the ADS unit sold for $500, the Advent
for $350, the Dynaco device sold for $19.

As to reproducing the concert hall "at home" - not possible excepting
perhaps somewhat with headphones. Keep in mind that EARS - such as
many of us have in some quantity *between* -1 and 3 are typically
deployed in pairs separated by a few inches of jelly and bone. What
they discern is a mix of many things all-at-the-same-time, and rely
on a very sophisticated but not very learned wet-ware system to make
sense of the incoming noise and winnow the desired noise from the
general mass of it. In a concert hall, that is all well enough. There
is not much between the various noises and the EARS, so that if the
wet-ware discerns well, and finds the result pleasing, it becomes
'music'. Not a hard concept.

Consider the average listening room - AVERAGE, not
dedicated-by-a-fanatic. It is a mix of surfaces, and includes a mix
of reproducers driven by some level of electronics. The reproducers
may be from a few square inches of surface reinforced by clever horns
and baffles (full-range single-driver horns) driven by fly-powered
triode amplifiers of a few watt, up to several square feet of surface
driven by brute-force amplifiers of a few hundred watts. NONE of them
have the capacity to reproduce a symphony orchestra at anything like
realistic volumes as consider the total vibrating surface area of an
orchestra in Tutti - or a single 30' bombard pipe. Not even close.

So, we try to get to some pleasing noise that is close-enough to
actual music as not to drive us instantly from the room screaming in
pain. Some try by means of a listening room engineered to a
fare-thee-well with a sweet-spot about as big in cubic area as the
average head. Makes for acutely uncomfortable listening, but can be
nearly-headphones enough to be more accurate than the alternative.
Others try for a general listening area that is clean enough to allow
for a much more general listening location (I am of this school) and
try for enough headroom (power) and speaker range (flat frequency
response) so as to get most of the original signal into the room.

And, of course, we have not even begun to discuss the many hundreds
of peripheral decisions made between the performance and the replay -
engineering, microphone placement, mixing, equalization and much
more.

I am not beginning to suggest or imply that it is a crap-shoot. But
for damned sure, it is not neurosurgery or even rocket science. What
it is, is a constantly moving target being fired on with a .22 pistol
with a loose barrel. One might hit on occasion, but that is not to be
counted on as the norm.

Again, we try to make pleasing noises using what is available to us.
Theory allows us to speculate on what might be based on what we see
and expect. But the actual practice is terribly inconvenient.
"Stereo" is merely one of many means that have a checkered history of
providing pleasing noise - sometimes.

I guess this is why I have five (5) active stereos in operation, and
speakers from Maggies to AR3as and some others between, from tube to
solid-state, and include vinyl, RtR, cassette and CD options (as well
as tuners, of course). All of them, I have managed to bring to a
pleasing state, few by the same measures.

But, the problem with STEREO is that it is not LIVE MUSIC. The
expectations of getting the latter from the former is a
contradiction-in-terms. And as such leads either to madness or
frustration.

Peter Wieck
Melrose Park, PA


Interesting treatise Peter, but I think you are needlessly complicating
things. The main characteristics that we can hear from speakers are the
frequency response and the radiation pattern. The frequency response part is
well in hand, no problem with microphones, sources, amplifiers, or wiring.
But the radiation pattern has not yet been sufficiently addressed in any
scientific or engineering sense with respect to stereo.

But it is not just radiation pattern, it is the result of radiation pattern
w respect to speaker positioning and room surfaces that we hear. Very little
attention has been paid to all that except for the erroneous advice to
dampen out all reflections. But stereo is not a "two ears, two speakers"
system and we do NOT want to hear just the direct sound from the speakers.
That should have been realization #1. If that had been studied, then there
would be out there some advice on the unanswered questions, what radiation
pattern should we desire, and what speaker positioning, and what room
treatment. Siegfried Linkwitz posed exactly those questions to the AES in a
recent paper about 7 years ago

The Challenge to Find the Optimum Radiation Pattern and Placement of Stereo
Loudspeakers in a Room for the Creation of Phantom Sources and Simultaneous
Masking of Real Sources (Paper #7959, Oct 2009)
If this had been studied enough during the stereo era, we would have some
answers and not be making the vast majority of speakers with all of the
drivers on just the front of the speaker box.

Again, my answer is to use the walls near the speakers as part of the
speaker system in a pattern that mimics that of the typical live sound
field. It is based on my AES preprint # 2869, Oct 1989, An Image Model
Theory for Stereophonic Sound. I have now had some speakers built based on
that theory that work as predicted in that paper of some 27 years ago. Very
little else matters to audibility of your stereo system, and most of the
factors that you mention are not that much of a problem at all and can
confuse rather than illuminate the problem.

Gary Eickmeier

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Default The Problem with Stereo

On Monday, June 27, 2016 at 7:49:51 AM UTC-4, Gary Eickmeier wrote:

Gary:

I will try to address your points as close to per-each as I am able. I am =
NOT disagreeing with you, but I am discussing the art of the possible.

All of the direct, early reflected, and reverberant fields of the origin=

al=20
would be compressed into arriving from just those two points in space, not=
=20
from the original directions of the sounds that were recorded. This is very=
=20
audible.

Yes. True. However, I am not so sure that it is possible to reproduce the e=
ntire sound-field of a concert venue without a bunch of additional processi=
ng even with the best of speakers. Keep in mind that in the concert venue, =
what is reflected and heard is delayed by some amount based on the addition=
al length-of-travel. This can be disconcerting (any sort of standing wave) =
or quite pleasant if it is somehow 'timed' to resonate pleasantly with the =
direct sound. Controlling that resonance will require a fair amount of atte=
ntion and/or processing. To-date, most systems have used a brute-force appr=
oach via electronics, or by forcing some specific sort of speaker array in =
a room of a specific shape.=20

Put another way - if a speaker is designed to reproduce the overall ambianc=
e of a concert venue by using the properties of the room in which they are =
deployed, and by careful dispersion of the sound, there is not necessarily =
any guarantee that the actual venue matches to the actual room such that th=
e results are pleasing. OR - the needs of the speakers in terms of the room=
are so specific that the room must be of specific dimensions and of a spec=
ific nature with specific surfaces and the listener in a specific location.=
Or, conversely, the speaker(s) must be designed to the room. Either is rea=
sonable if a unique system is acceptable.=20

But it is not just radiation pattern, it is the result of radiation patt=

ern w respect to speaker positioning and room surfaces that we hear. Very l=
ittle attention has been paid to all that except for the erroneous advice t=
o dampen out all reflections. But stereo is not a "two ears, two speakers" =
system and we do NOT want to hear just the direct sound from the speakers. =
That should have been realization #1. If that had been studied, then there =
would be out there some advice on the unanswered questions, what radiation =
pattern should we desire, and what speaker positioning, and what room treat=
ment.

Sure. And I do not want to commit the fallacy of begging the question. Howe=
ver, what is there to control the additional radiation pattern so that it a=
ctually resembles the original sound in the first place given the limitatio=
ns of two channels and two speakers? How is that translated to the speaker =
in such a way as the drivers know what they are to do with it? Again, the i=
ssue of how the reflections resonate with the original signal is the first =
clue as to the difficulty of both recording AND reproducing this. Brute for=
ce has been the process to date, from the simple Hafler Circuit to systems =
with more computing power than the space shuttle.=20

The Challenge to Find the Optimum Radiation Pattern and Placement of Ste=

reo Loudspeakers in a Room for the Creation of Phantom Sources and Simultan=
eous Masking of Real Sources (Paper #7959, Oct 2009)=20
If this had been studied enough during the stereo era, we would have some=
=20
answers and not be making the vast majority of speakers with all of the=20
drivers on just the front of the speaker box.

Back in the days of Vilchur, Allison, Kloss and the Boston Sound in general=
, it was never expected that anyone would sit practically on top of the sp=
eakers. "modern" speakers evolved from other sound systems, primarily from =
the Cinema, where there was a fairly large distance between the user and th=
e source. Such speakers were typically massive horns set behind the screen =
and did well enough for the purposes - but never pretended at anything like=
high fidelity. Vilchur developer the acoustic-suspension concept which rei=
nforced the bass with sufficient accuracy that the mid and treble could be =
made powerful enough to compete in one speaker. Ever look at a vintage cine=
ma speaker? One designed to be driven by a pair of 6L6s in PP? they include=
an amazing amount of woodwork, and perhaps three drivers, all horns. No cr=
ossover to speak of either.=20

All of a sudden, all that could be crammed into a tiny little box. And AR (=
and others) used to demonstrate their speakers in small concert venues by p=
lacing them on stage with the musicians and switching between them. In many=
cases the (probably carefully chosen) audience professed not to be able to=
tell the difference. So, the front-facing speaker is not the prima-fascia =
problem. It is how they are deployed in our listening venues and how we use=
them.=20

AR (and others) started to recognize this issue fairly early on, and starte=
d 'messing' with the design of their speakers. The 10=CF=80 speaker used co=
ntrols for each individual driver to "tune" it to the room and even tune it=
to locations not directly on a wall or on the floor. They experimented wit=
h multiple drivers arrayed at angles (MST/LST/LSTII), sub-sat systems (Athe=
na), holographic systems (M4,5,6), planar arrays with side or down-firing w=
oofers and the tuning options of the earlier series (9/90/LS) and much more=
.. Point being that they did recognize that few individuals could have a roo=
m approaching 4,000 cubic feet and fewer had full freedom to place their sp=
eakers. Magnepan, KLH, Accustat and a several others designed planar speake=
rs with square feet of surface radiating front and back, magnetic and elect=
rostatic...=20

I think that speakers (and other transducers) are the last great opportunit=
y in audio reproduction. Electronics are done. Tuners are done. Most everyt=
hing else is done. But I also think that your research needs to move somewh=
at away from theory and address the very real aspects of placement, room ac=
oustics and speaker array to address the incompatibility potential between =
the actual performance venue and the reproduction venue. I think that much =
of this discussion involves angels and pinheads... and without Deacon Musrh=
at available to do the actual calculations, direct experimentation will be =
much better than theory. I remember your previous post on speaker design, a=
nd that you had realized the design and were experimenting with it. THOSE r=
esults will be the proof of the pudding (in the eating).=20

I use AR or Maggie for most of my references as I am most familiar with the=
ir designs and have owned or own many variants. But, they are only two of m=
any, of course. And as a complete aside, my 12 year old granddaughter has m=
y Revox sub-sat system as her room is incredibly difficult for speakers. Th=
e sub-woofer found a convenient location serving as a small table, and the =
mid-tweets were small enough to allow placement where they did the most goo=
d. She is thrilled with the sound (an all-Revox system as it happens) and h=
as greatly reduced the Bieb for actual classical music and more.=20

Peter Wieck
Melrose Park, PA
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Default The Problem with Stereo

Peter -

Without re-quoting the entire thing, which is available above obviously -
another great and interesting post. But let me concentrate on just one
aspect of this speaker-room interface problem.

Most (normal) audiophilles who haven't studied all this will not know the
difference between the "spatial" and the "temporal" characteristics that you
discuss. But we must differentiate the two because the spatial is the much
more important and audible one that has not been studied enough. The spatial
means the angles from which the various sound fields arrive at the listener.
For example, the direct comes straight from the instruments (or speakers),
the early reflected comes from a much wider and deeper set of reflections
from the soundstage area but with a significant and important time delay,
and the reverberant comes from all around, evenly, with (hopefully) a smooth
decay to inaudibility, considered to be 60 dB below the loudest sounds. When
we record we should try to record not just the instruments but also the
early reflected sound as part of the whole soundstage, helping to flesh out
the full sound power of the instruments and giving us the timbre of the
instruments and the perception of spaciousness that we hear live.

This perception of spaciousness - very important to stereo and the musical
enjoyment, live or reproduced, is caused by the physical placement of those
recorded reflected sounds from angles that are similar to the original. I do
it by reflection, but you could do it with extra speakers placed near the
front and side walls of a smaller room. Anyway, it is the directions from
which those sounds arrive that is involved in this perception of
spaciousness. This cannot be reproduced by the direct speakers no matter how
good they are, it must come from the radiation pattern by means of
reflection or from those extra speakers.

OK, so the temporal aspect is also important, but it does not come from the
temporal delay of those reflections we were just talking about above. It was
actually contained in the recording, both the delay of the early reflections
and the full decay of the reverberant field. You will often see the
criticism of a direct and reflecting type of speaker that our home rooms
are not as big as the original, so it can't work. But now I hope you (all)
can see that if we address the spatial part, the temporal will take care of
itself.

Moral of the story, we must learn to separate in our thinking the spatial
from the temporal characteristics of sound fields.

Gary Eickmeier

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Scott[_6_] Scott[_6_] is offline
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Posts: 642
Default The Problem with Stereo

On Tuesday, June 28, 2016 at 4:11:20 AM UTC-7, Gary Eickmeier wrote:
Peter -
=20
Without re-quoting the entire thing, which is available above obviously -=

=20
another great and interesting post. But let me concentrate on just one=20
aspect of this speaker-room interface problem.
=20
Most (normal) audiophilles who haven't studied all this will not know the=

=20
difference between the "spatial" and the "temporal" characteristics that =

you=20
discuss. But we must differentiate the two because the spatial is the muc=

h=20
more important and audible one that has not been studied enough. The spat=

ial=20
means the angles from which the various sound fields arrive at the listen=

er.=20
For example, the direct comes straight from the instruments (or speakers)=

,=20
the early reflected comes from a much wider and deeper set of reflections=

=20
from the soundstage area but with a significant and important time delay,=

=20
and the reverberant comes from all around, evenly, with (hopefully) a smo=

oth=20
decay to inaudibility, considered to be 60 dB below the loudest sounds. W=

hen=20
we record we should try to record not just the instruments but also the=

=20
early reflected sound as part of the whole soundstage, helping to flesh o=

ut=20
the full sound power of the instruments and giving us the timbre of the=

=20
instruments and the perception of spaciousness that we hear live.
=20
This perception of spaciousness - very important to stereo and the musica=

l=20
enjoyment, live or reproduced, is caused by the physical placement of tho=

se=20
recorded reflected sounds from angles that are similar to the original. I=

do=20
it by reflection, but you could do it with extra speakers placed near the=

=20
front and side walls of a smaller room. Anyway, it is the directions from=

=20
which those sounds arrive that is involved in this perception of=20
spaciousness. This cannot be reproduced by the direct speakers no matter =

how=20
good they are, it must come from the radiation pattern by means of=20
reflection or from those extra speakers.
=20
OK, so the temporal aspect is also important, but it does not come from t=

he=20
temporal delay of those reflections we were just talking about above. It =

was=20
actually contained in the recording, both the delay of the early reflecti=

ons=20
and the full decay of the reverberant field. You will often see the=20
criticism of a direct and reflecting type of speaker that our home rooms=

=20
are not as big as the original, so it can't work. But now I hope you (all=

)=20
can see that if we address the spatial part, the temporal will take care =

of=20
itself.
=20
Moral of the story, we must learn to separate in our thinking the spatial=

=20
from the temporal characteristics of sound fields.
=20
Gary Eickmeier


You can't separate them. Spacial perception heavily relies on temporal char=
acter of sound. You can't "hear angles." You can hear temporal differences =
between the right and left ear in sound coming from an angle which your bra=
in will process as sound coming from an angle. Spacial perception relies on=
temporal information.



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Peter Wieck Peter Wieck is offline
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Posts: 2,418
Default The Problem with Stereo

On Thursday, June 30, 2016 at 7:45:42 PM UTC-4, Scott wrote:

=20
You can't separate them. Spacial perception heavily relies on temporal ch=

aracter of sound. You can't "hear angles." You can hear temporal difference=
s between the right and left ear in sound coming from an angle which your b=
rain will process as sound coming from an angle. Spacial perception relies =
on temporal information.

Thank you for writing in few words what typically takes me many. Must be th=
e German in me - never use one word where three-or-more will do better.=20

But the point of all this is that how sound is delivered in a listening roo=
m from linear motors driven by electronic impulses is nothing like what hap=
pens in a concert venue, unless the instruments are electronically reinforc=
ed (which is not uncommon in these troubled times). The sound is some analo=
g of the original noise that has been processed (engineered) into a shape t=
o be delivered via the motors with hopefully pleasing results.=20

It may be possible to enable the motors to provide noise that is 'spatially=
' closer to the original if the room has that capacity and the motors are c=
apable of directional delivery and the signal is there to be delivered. But=
it would require additional levels of processing, and probably additional =
channels. I am not so sure whether conventional binaural signals have that =
information in the correct form. This is where experimentation under real-w=
orld conditions will separate the theory from the actual.=20

I, at least, have experimented with the more brute-force approaches, passiv=
e and active. They are best described as "interesting", but not really some=
thing I would set out to accomplish in every venue. Often it is distracting=
, for a fact, and very nearly never riveting.=20

Peter Wieck
Melrose Park, PA=20
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Scott[_6_] Scott[_6_] is offline
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Posts: 642
Default The Problem with Stereo

On Friday, July 1, 2016 at 5:23:12 AM UTC-7, Peter Wieck wrote:
On Thursday, June 30, 2016 at 7:45:42 PM UTC-4, Scott wrote:
=20
=20
You can't separate them. Spacial perception heavily relies on temporal =

character of sound. You can't "hear angles." You can hear temporal differen=
ces between the right and left ear in sound coming from an angle which your=
brain will process as sound coming from an angle. Spacial perception relie=
s on temporal information.
=20
Thank you for writing in few words what typically takes me many. Must be =

the German in me - never use one word where three-or-more will do better.=
=20
=20
But the point of all this is that how sound is delivered in a listening r=

oom from linear motors driven by electronic impulses is nothing like what h=
appens in a concert venue, unless the instruments are electronically reinfo=
rced (which is not uncommon in these troubled times). The sound is some ana=
log of the original noise that has been processed (engineered) into a shape=
to be delivered via the motors with hopefully pleasing results.=20
=20
It may be possible to enable the motors to provide noise that is 'spatial=

ly' closer to the original if the room has that capacity and the motors are=
capable of directional delivery and the signal is there to be delivered. B=
ut it would require additional levels of processing, and probably additiona=
l channels. I am not so sure whether conventional binaural signals have tha=
t information in the correct form. This is where experimentation under real=
-world conditions will separate the theory from the actual.=20
=20
I, at least, have experimented with the more brute-force approaches, pass=

ive and active. They are best described as "interesting", but not really so=
mething I would set out to accomplish in every venue. Often it is distracti=
ng, for a fact, and very nearly never riveting.=20
=20
Peter Wieck
Melrose Park, PA


I honestly think real imaging is not what most people think it is. We have =
the aid of visual cues in live concerts and this goes a long way towards cr=
eating our perception of aural imaging. IMO "accurate" imaging in playback,=
that being imaging that is just like what we hear in concert, would be con=
sidered very inadequate. IME the imaging we get from playback is far more c=
lear and specific. And I think that it needs to be to compensate for the la=
ck of visual cues. Stereo recording and playback can create a pretty amazin=
g aural illusion of imaging and spaciousness. I don't think there is any ne=
ed to "fix" it. It works quite well as is. We can never recreate the concer=
t experience in the playback room. It's a dragon chase.
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Gary Eickmeier Gary Eickmeier is offline
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Posts: 1,449
Default The Problem with Stereo

Peter Wieck wrote:
On Thursday, June 30, 2016 at 7:45:42 PM UTC-4, Scott wrote:


You can't separate them. Spacial perception heavily relies on
temporal character of sound. You can't "hear angles." You can hear
temporal differences between the right and left ear in sound coming
from an angle which your brain will process as sound coming from an
angle. Spacial perception relies on temporal information.


Thank you for writing in few words what typically takes me many. Must
be the German in me - never use one word where three-or-more will do
better.

But the point of all this is that how sound is delivered in a
listening room from linear motors driven by electronic impulses is
nothing like what happens in a concert venue, unless the instruments
are electronically reinforced (which is not uncommon in these
troubled times). The sound is some analog of the original noise that
has been processed (engineered) into a shape to be delivered via the
motors with hopefully pleasing results.

It may be possible to enable the motors to provide noise that is
'spatially' closer to the original if the room has that capacity and
the motors are capable of directional delivery and the signal is
there to be delivered. But it would require additional levels of
processing, and probably additional channels. I am not so sure
whether conventional binaural signals have that information in the
correct form. This is where experimentation under real-world
conditions will separate the theory from the actual.

I, at least, have experimented with the more brute-force approaches,
passive and active. They are best described as "interesting", but not
really something I would set out to accomplish in every venue. Often
it is distracting, for a fact, and very nearly never riveting.

Peter Wieck
Melrose Park, PA


Peter and Scott -

OK you've got me. I am using a trick processor that is super secret - or
was, until you guys exposed me. It functions as a spatially arrayed,
spectrally shaped, temporally delayed sound field simulator. It took about 5
months to construct from plans that I gave my builders when I built the
house. Well, as long as we're here, let me describe how you can build one
too, to check my results on your own. Maybe it will sell.

When we built my media room - combination audio and video - I specified a
rectangular space 20 by 30 feet, with cathedral ceiling and specular
reflectivity at the speaker end. When I installed my speakers I placed them
exactly 5 feet out from the side walls and an equal amount out from the
front wall. The speakers have a negative directivity index, putting out 6 dB
more sound in the reflecting direction than toward the listeners. This is to
feed the simulator more of the sound than goes out the front as direct sound
from the recording.

The simulator then takes over the processing. The speakers face diamondwise
into the room, the four driver faces aiming at 45 degrees from the center
line. The rear radiation thus goes out toward the front wall with a
vengeance, half of it going toward the other speaker and half of it going at
a 45° angle toward the corner of the room, whereupon it gets reflected, or
processed, to come from the adjacent side wall with a certain delay and
wider spatial angle than the direct sound from that same speaker. In this
manner the sound gets processed so that it comes from spatially similar
angles to the live sound that was recorded and the soundstage takes on a
width and depth that it wouldn't have unprocessed.

I call the mechanism of my processor "reflection" and the whole idea of
doing it this way "Image Model Theory."

So, Scott, even though you can't hear angles, architectural acousticians
have been designing concert halls to do this same process to the live sound
for years and years. Please don't tell them that we can't hear angles
because they think (and I agree) that the spaciousness brought out by the
reflected sound gives the music a pleasing effect and they actually strive
for it in their designs. Peter, so right, now you know the mechanism of the
additional levels of processing. The only question remaining is do they
record any of the early reflected sound, or ambience, while recording the
direct sound of the instruments? Nah - impossible - they shut the
microphones off well before all of that reflected sound can reach them,
thank God.

We can't hear angles anyway.

Gary Eickmeier

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Scott[_6_] Scott[_6_] is offline
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Posts: 642
Default The Problem with Stereo

On Friday, July 1, 2016 at 7:37:29 PM UTC-7, Gary Eickmeier wrote:
Peter Wieck wrote:
On Thursday, June 30, 2016 at 7:45:42 PM UTC-4, Scott wrote:


You can't separate them. Spacial perception heavily relies on
temporal character of sound. You can't "hear angles." You can hear
temporal differences between the right and left ear in sound coming
from an angle which your brain will process as sound coming from an
angle. Spacial perception relies on temporal information.


Thank you for writing in few words what typically takes me many. Must
be the German in me - never use one word where three-or-more will do
better.

But the point of all this is that how sound is delivered in a
listening room from linear motors driven by electronic impulses is
nothing like what happens in a concert venue, unless the instruments
are electronically reinforced (which is not uncommon in these
troubled times). The sound is some analog of the original noise that
has been processed (engineered) into a shape to be delivered via the
motors with hopefully pleasing results.

It may be possible to enable the motors to provide noise that is
'spatially' closer to the original if the room has that capacity and
the motors are capable of directional delivery and the signal is
there to be delivered. But it would require additional levels of
processing, and probably additional channels. I am not so sure
whether conventional binaural signals have that information in the
correct form. This is where experimentation under real-world
conditions will separate the theory from the actual.

I, at least, have experimented with the more brute-force approaches,
passive and active. They are best described as "interesting", but not
really something I would set out to accomplish in every venue. Often
it is distracting, for a fact, and very nearly never riveting.

Peter Wieck
Melrose Park, PA

=20
Peter and Scott -
=20
OK you've got me. I am using a trick processor that is super secret - or=

=20
was, until you guys exposed me. It functions as a spatially arrayed,=20
spectrally shaped, temporally delayed sound field simulator. It took abou=

t 5=20
months to construct from plans that I gave my builders when I built the=

=20
house. Well, as long as we're here, let me describe how you can build one=

=20
too, to check my results on your own. Maybe it will sell.
=20
When we built my media room - combination audio and video - I specified a=

=20
rectangular space 20 by 30 feet, with cathedral ceiling and specular=20
reflectivity at the speaker end. When I installed my speakers I placed th=

em=20
exactly 5 feet out from the side walls and an equal amount out from the=

=20
front wall. The speakers have a negative directivity index, putting out 6=

dB=20
more sound in the reflecting direction than toward the listeners. This is=

to=20
feed the simulator more of the sound than goes out the front as direct so=

und=20
from the recording.
=20
The simulator then takes over the processing. The speakers face diamondwi=

se=20
into the room, the four driver faces aiming at 45 degrees from the center=

=20
line. The rear radiation thus goes out toward the front wall with a=20
vengeance, half of it going toward the other speaker and half of it going=

at=20
a 45=C2=B0 angle toward the corner of the room, whereupon it gets reflect=

ed, or=20
processed, to come from the adjacent side wall with a certain delay and=

=20
wider spatial angle than the direct sound from that same speaker. In this=

=20
manner the sound gets processed so that it comes from spatially similar=

=20
angles to the live sound that was recorded and the soundstage takes on a=

=20
width and depth that it wouldn't have unprocessed.
=20
I call the mechanism of my processor "reflection" and the whole idea of=

=20
doing it this way "Image Model Theory.


"Gary, we know what you've been doing. You have told us about it many times=
.. You like your stereo bounced off the walls of your listening room. You fi=
nd it pleasing and that is completely fine. I have heard the Bose 901s on s=
everal occasions including a couple of demos set up by Bose themselves in c=
ustom rooms built just for the 901s. It wasn't to my liking. Not one bit ac=
tually.=20

=20
So, Scott, even though you can't hear angles, architectural acousticians=

=20
have been designing concert halls to do this same process to the live sou=

nd=20
for years and years.



Concert halls serve a very very different purpose than a playback room. Exc=
ellent concert halls tend to sound really bad with PA systems. Good acousti=
cs for live acoustic music are lousy acoustics for stereo systems. A concer=
t hall helps create the sound of the performance. Recording and playback do=
es not create it, it documents it and tries to simulate the effect. Totally=
different things.

Please don't tell them that we can't hear angles=20


I already explained what it is you are actually hearing. Temporal differenc=
es between your two ears. If you think you can actually hear angles without=
the temporal differences put it to the test. See if you can still "hear an=
gles" with one ear blocked so your brain does not receive the temporal diff=
erences.=20

because they think (and I agree) that the spaciousness brought out by the=

=20
reflected sound gives the music a pleasing effect and they actually striv=

e=20
for it in their designs.


No doubt reflected sound/ hall acoustics has a profound effect on the sound=
quality of live acoustic music. But the spaciousness is real. The separati=
on of instruments in a live concert is due to...the actual separation of in=
struments in a live concert. Think about it. There is a whole science behin=
d concert hall design. It's something I find quite interesting and have don=
e a fair amount of research on. It does not apply to stereo playback rooms.=
They are entirely different beasts and serve very different purposes. On t=
op of that much of what we perceive as "imaging" and "spaciousness" at a li=
ve concert is due to visual cues. We don't get visual cues in stereo playba=
ck. If you could get the same exact sound in the playback room that you got=
at a concert hall the perception of imaging would not sound "right" and wo=
uld be deemed inadequate.=20

Peter, so right, now you know the mechanism of the=20
additional levels of processing. The only question remaining is do they=

=20
record any of the early reflected sound, or ambience, while recording the=

=20
direct sound of the instruments? Nah - impossible - they shut the=20
microphones off well before all of that reflected sound can reach them,=

=20
thank God.


Reflected sound is recorded along with direct sound with most traditional s=
tereo recordings. It's already there and is brought out quite nicely with a=
well designed stereo system in a stereo room that is not plagued by a lot =
of reflectivity. No need to double up on what was already recorded at the c=
oncert hall. It only creates spacial confusion by presenting spacial cues f=
rom two different spaces on top of each other. This is not to say that the =
stereo recording and playback can't be augmented by distortions. It can. Vi=
nyl playback and tube electronics do this quite nicely. So much so that man=
y people confuse these euphonic distortions with greater accuracy because t=
hey often have the overall effect of greater realism. I personally find tha=
t splashing the sound all over the walls is a distortion that simply does n=
ot enhance the perception of realism nor does it sound in any way pleasing.=
If you like it that is just fine. We all get to choose for ourselves what =
we like.=20

=20
We can't hear angles anyway.
=20
Gary Eickmeier


If you can do it with one ear let me know.=20

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Gary Eickmeier Gary Eickmeier is offline
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Posts: 1,449
Default The Problem with Stereo

Scott wrote:

"Gary, we know what you've been doing. You have told us about it many
times. You like your stereo bounced off the walls of your listening
room. You find it pleasing and that is completely fine. I have heard
the Bose 901s on several occasions including a couple of demos set up
by Bose themselves in custom rooms built just for the 901s. It wasn't
to my liking. Not one bit actually.


Not talking about 901s.


I already explained what it is you are actually hearing. Temporal
differences between your two ears. If you think you can actually hear
angles without the temporal differences put it to the test. See if
you can still "hear angles" with one ear blocked so your brain does
not receive the temporal differences.


This is some of the crazier statements that you have made Scott. Still not
sure which Scott you are - but can't hear angles? All of a sudden we can't
hear in stereo? What kind of nonsense is this? Where did you get it?


No doubt reflected sound/ hall acoustics has a profound effect on the
sound quality of live acoustic music. But the spaciousness is real.


Yes, and it needs to be real on playback as well.

The separation of instruments in a live concert is due to...the
actual separation of instruments in a live concert. Think about it.
There is a whole science behind concert hall design. It's something I
find quite interesting and have done a fair amount of research on. It
does not apply to stereo playback rooms. They are entirely different
beasts and serve very different purposes. On top of that much of what
we perceive as "imaging" and "spaciousness" at a live concert is due
to visual cues. We don't get visual cues in stereo playback. If you
could get the same exact sound in the playback room that you got at a
concert hall the perception of imaging would not sound "right" and
would be deemed inadequate.


No, they are not different. If you don't reproduce, or reconstruct, the
spatial realism it will sound different.


Reflected sound is recorded along with direct sound with most
traditional stereo recordings. It's already there and is brought out
quite nicely with a well designed stereo system in a stereo room that
is not plagued by a lot of reflectivity. No need to double up on what
was already recorded at the concert hall. It only creates spacial
confusion by presenting spacial cues from two different spaces on top
of each other.


You would be correct if we were talking about binaural systems. Stereo is a
field-type system. Do you know the difference?

My message is simple: When both ears are free to hear all sound fields in
front of them, the system is not operating binaurally. Stereo does not work
by piping the two "signals" to the ears, it works by recreating sound fields
in rooms. Those fields must have the same spatial characteristics as the
live sound. The most efficient way to reproduce the early reflected field is
by reflection. If you do this with the speakers positioned in a certain way
and with a certain radiation pattern the imaging will be improved and the
spaciousness and depth will be reproduced. If you do it by directional
speakers with sound killing in the room you will be folding the early
refected field onto the direct field, destroying the spaciousness that was
recorded. It will sound like double mono. All of this should have been
obvious to you after a certain number of years of listening to speakers of
various radiation patterns. Can you hear differences among box speakers,
dipoles, bipoles, omnis? Good. Those differences are caused by differences
in the image model, or reflection patterns and strengths, among those
speakers. Study that for a while.

Gary Eickmeier



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Peter Wieck Peter Wieck is offline
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Posts: 2,418
Default The Problem with Stereo

Please note the interpolations.=20

But, first a few things. I thought my main listening room was large at 17 x=
22 x 10 feet. But, 20 x 30 is as large as many intimate performance venues=
, and as such has some greater possibilities for spatial performance than a=
smaller venue. And, as apparently, that room has designed reflective prope=
rties and (I am sure) controlled surfaces with carefully designed ceiling a=
ngles, this would be even more so.=20

In a sense, this is not 'fair' to the general premise as such a room would =
swallow up many speakers and many electronic configurations as it would sim=
ply be too large to be filled by a typical system.=20

On Monday, July 4, 2016 at 5:57:58 PM UTC-4, Gary Eickmeier wrote:
Scott wrote:
=20
"Gary, we know what you've been doing. You have told us about it many
times. You like your stereo bounced off the walls of your listening
room. You find it pleasing and that is completely fine. I have heard
the Bose 901s on several occasions including a couple of demos set up
by Bose themselves in custom rooms built just for the 901s. It wasn't
to my liking. Not one bit actually.

=20
Not talking about 901s.
=20
=20
I already explained what it is you are actually hearing. Temporal
differences between your two ears. If you think you can actually hear
angles without the temporal differences put it to the test. See if
you can still "hear angles" with one ear blocked so your brain does
not receive the temporal differences.

=20
This is some of the crazier statements that you have made Scott. Still no=

t=20
sure which Scott you are - but can't hear angles? All of a sudden we can'=

t=20
hear in stereo? What kind of nonsense is this? Where did you get it?


I think this is a careful interpretation of Scott's statement. I read Scott=
's position as that the brain adds the perception of angles and locational =
information to the interpretation of sound based on the fact that the infor=
mation is delivered as part of the process. The violins on the left of the =
stage have angular information as recorded that is different from the percu=
ssion to the rear or the larger strings to the right. And this, the ears vi=
a the brain interprets as spatial relationships. One ear is akin to depth p=
erception with only one eye. Just possible with large amounts of practice (=
one-eyed people can learn to drive safely, climb stairs and other sorts of =
activities that typically require spatial perception). But, it is not a ski=
ll that normally-sighted (or eared) individuals need to cultivate.=20

=20
=20
No doubt reflected sound/ hall acoustics has a profound effect on the
sound quality of live acoustic music. But the spaciousness is real.

=20
Yes, and it needs to be real on playback as well.


No, not really. The brain does a pretty good job of adding the information =
based on temporal clues. HOWEVER - in a room as large as the one described,=
most speakers would simply not be up to the task of providing those cues w=
ith sufficient acuity as to overcome the other issues (size and such) inher=
ent to the room. I am not even sure my Maggies could do it even with my 200=
watt amp. So, there would be a "problem with stereo" in that venue, for su=
re.=20

=20
The separation of instruments in a live concert is due to...the
actual separation of instruments in a live concert. Think about it.
There is a whole science behind concert hall design. It's something I
find quite interesting and have done a fair amount of research on. It
does not apply to stereo playback rooms. They are entirely different
beasts and serve very different purposes. On top of that much of what
we perceive as "imaging" and "spaciousness" at a live concert is due
to visual cues. We don't get visual cues in stereo playback. If you
could get the same exact sound in the playback room that you got at a
concert hall the perception of imaging would not sound "right" and
would be deemed inadequate.

=20
No, they are not different. If you don't reproduce, or reconstruct, the=

=20
spatial realism it will sound different.
=20


Yes, it will, and yes, it does. Unless - think this through - the actual re=
cording uses a single pair of microphones separated by the approximate dist=
ance of human ears, with some pretty heavy insulation between them and some=
pretty special reflector devices around them, they are only an interpretat=
ion of what any individual hears in a concert venue. And front-row-center D=
OES NOT sound like second-balcony-restricted-view. Nor, even, 12th-row-cent=
er.

=20
Reflected sound is recorded along with direct sound with most
traditional stereo recordings. It's already there and is brought out
quite nicely with a well designed stereo system in a stereo room that
is not plagued by a lot of reflectivity. No need to double up on what
was already recorded at the concert hall. It only creates spacial
confusion by presenting spacial cues from two different spaces on top
of each other.

=20
You would be correct if we were talking about binaural systems. Stereo is=

a=20
field-type system. Do you know the difference?


"Stereo" is a recording of a sound field via point-sources, mixed into a bi=
naural signal delivered electronically and separately to two separate point=
s. What happens from there is a combination of the speakers, the room, and =
the engineer's idea(s). However it is sliced and diced, that is what 'stere=
o' is.=20

=20
My message is simple: When both ears are free to hear all sound fields in=

=20
front of them, the system is not operating binaurally. Stereo does not wo=

rk=20
by piping the two "signals" to the ears, it works by recreating sound fie=

lds=20
in rooms.=20


No, that would be headphones. Funny thing about headphones - they get _exac=
tly_ the same signal as speakers do - they just have less confusion around =
them what with walls, glass, floors, rugs, space, position and such. Expect=
ing a room to behave as headphones is silly.=20

Those fields must have the same spatial characteristics as the=20
live sound. The most efficient way to reproduce the early reflected field=

is=20
by reflection. If you do this with the speakers positioned in a certain w=

ay=20
and with a certain radiation pattern the imaging will be improved and the=

=20
spaciousness and depth will be reproduced. If you do it by directional=20
speakers with sound killing in the room you will be folding the early=20
refected field onto the direct field, destroying the spaciousness that wa=

s=20
recorded.=20


Neat trick if it can be done. Point being that a room is NOT a concert venu=
e. When, under controlled conditions, they are both the same, then there re=
ally will be no issues between speakers and live performances. AR (and othe=
r speaker makers) proved this contention over and over through the 1980s. O=
utside of such controlled conditions they are NOT the same.=20

It will sound like double mono.

YIKES! Double-mono. Not hardly. I don't think that in 40+ years of ditherin=
g around this hobby I have EVER been in a room so awful or with equipment s=
o poor as to confuse any sort of monaural signal with any sort of stereo si=
gnal - well, perhaps the time I met with a pair of Bose 901s - it all sound=
ed like mud. Stereo/mono, but still mud.=20

All of this should have been=20
obvious to you after a certain number of years of listening to speakers o=

f=20
various radiation patterns. Can you hear differences among box speakers,=

=20
dipoles, bipoles, omnis? Good. Those differences are caused by difference=

s=20
in the image model, or reflection patterns and strengths, among those=20
speakers. Study that for a while.


Those differences are, in fact, due to the systems you describe. But as per=
ceived by the ears, the differences are entirely temporal when they are NOT=
due to differences in performance curves and placement. A Cerwin Vega spea=
ker with a 15" woofer, no audible midrange and a highly directional tweeter=
is an entirely different species than a Klipschorn or a high-end Maggie, o=
r an AR9, or a KLH 11.=20

I think your listening room allows you to cure a problem that is not releva=
nt to most of us, to your pleasure and advantage. But what applies there do=
es not necessarily apply elsewhere.=20

Peter Wieck
Melrose Park, PA
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Scott[_6_] Scott[_6_] is offline
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Posts: 642
Default The Problem with Stereo

On Monday, July 4, 2016 at 2:57:58 PM UTC-7, Gary Eickmeier wrote:
Scott wrote:
=20
"Gary, we know what you've been doing. You have told us about it many
times. You like your stereo bounced off the walls of your listening
room. You find it pleasing and that is completely fine. I have heard
the Bose 901s on several occasions including a couple of demos set up
by Bose themselves in custom rooms built just for the 901s. It wasn't
to my liking. Not one bit actually.

=20
Not talking about 901s.


You are talking about the principle on which the 901s work and let's not fo=
rget that they were your long time reference speakers and it was your exper=
ience with them that lead you down the path of advocacy of this idea of bou=
ncing the playback off the walls of the listening room. So my experience wi=
th the 901s is relevant.=20
=20
=20
I already explained what it is you are actually hearing. Temporal
differences between your two ears. If you think you can actually hear
angles without the temporal differences put it to the test. See if
you can still "hear angles" with one ear blocked so your brain does
not receive the temporal differences.

=20
This is some of the crazier statements that you have made Scott. Still no=

t=20
sure which Scott you are - but can't hear angles?


Not what I said. I said our perception of sound from angles is reliant on t=
emporal information. You asserted that we can separate temporal and spacial=
cues. You can't. You won't get spacial cues without the temporal qualities=
of sound. That is one of the reasons we need two ears to perceive spacial =
information of sound.=20

All of a sudden we can't=20
hear in stereo?



Where did that come from? It didn't come from me. I never said anything rem=
otely close to that.=20


What kind of nonsense is this?


It's the kind of nonsense you have arbitrarily brought into the conversatio=
n and wrongly attributed to me. I never said you can't hear angles. I speci=
fically said that hearing/perceiving angles is reliant on temporal content =
of the sound. I certainly never said one can not hear stereo. i said nothin=
g even close to that.

Where did you get it?


Where did you get it? Certainly not from any of my posts.=20

=20
=20
No doubt reflected sound/ hall acoustics has a profound effect on the
sound quality of live acoustic music. But the spaciousness is real.

=20
Yes, and it needs to be real on playback as well.


It can't be. One would have to tear down their listening room, build a repl=
ica of the original hall, toss out the recording and create a new recording=
with a channel for each musician in the original recording with a speaker =
in the same place as the musician occupied and then somehow make each speak=
er have the same exact radiation pattern as the actual instrument played. A=
ND we would need to find a way to record the original instruments in such a=
way that we capture the actual vibration of the instrument itself and not =
the air borne sound. Then we need to find a way to do that for the next rec=
ording we want to play which would likely be a different hall, different mu=
sicians, different instruments etc etc etc. Until we get Star Trek holodeck=
s this simply isn't going to be how stereo recording and playback works.=20

=20
The separation of instruments in a live concert is due to...the
actual separation of instruments in a live concert. Think about it.
There is a whole science behind concert hall design. It's something I
find quite interesting and have done a fair amount of research on. It
does not apply to stereo playback rooms. They are entirely different
beasts and serve very different purposes. On top of that much of what
we perceive as "imaging" and "spaciousness" at a live concert is due
to visual cues. We don't get visual cues in stereo playback. If you
could get the same exact sound in the playback room that you got at a
concert hall the perception of imaging would not sound "right" and
would be deemed inadequate.

=20
No, they are not different. If you don't reproduce, or reconstruct, the=

=20
spatial realism it will sound different.


The function of a playback room and a concert hall are quite different. the=
re is a very good reason why PA systems consistently sound terrible in exce=
llent concert halls. They weren't designed for playback.=20

=20
=20
Reflected sound is recorded along with direct sound with most
traditional stereo recordings. It's already there and is brought out
quite nicely with a well designed stereo system in a stereo room that
is not plagued by a lot of reflectivity. No need to double up on what
was already recorded at the concert hall. It only creates spacial
confusion by presenting spacial cues from two different spaces on top
of each other.

=20
You would be correct if we were talking about binaural systems. Stereo is=

a=20
field-type system. Do you know the difference?


Binaural systems are based on use of headphones and dummy head microphone a=
rrays. This has nothing to do with the subject at hand. I clearly would *no=
t* be correct if I were talking about binaural recordings since there is no=
issue with playback room reflections when we are dealing with headphones. =
I absolutely am correct when I assert that listening room reflections creat=
e spacial cue confusion when they are present with the playback of stereo r=
ecordings that captured hall ambiance and spacial cues from the original ac=
oustic event recorded. I know it from a great deal of experience.=20


=20
My message is simple: When both ears are free to hear all sound fields in=

=20
front of them, the system is not operating binaurally. Stereo does not wo=

rk=20
by piping the two "signals" to the ears, it works by recreating sound fie=

lds=20
in rooms.


And your message is plainly wrong. Stereo recording and playback is not des=
igned to "recreate soundfields of the original recordings." It is designed =
to create an aural illusion of experiencing the original sound field from o=
ne fixed position in that sound field. =20


Those fields must have the same spatial characteristics as the=20
live sound. The most efficient way to reproduce the early reflected field=

is=20
by reflection.



If you were right, (you aren't) we would be dead in the water since it is p=
retty clear that we cannot create "the same spatial characteristics as the=
=20
live sound." in our listening rooms. You can't cram a concert hall in your=
listening room.


If you do this with the speakers positioned in a certain way=20
and with a certain radiation pattern the imaging will be improved and the=

=20
spaciousness and depth will be reproduced.


You may like the results but the results certainly are not any kind of accu=
rate reconstruction of the original sound field. that is not possible.=20


If you do it by directional=20
speakers with sound killing in the room you will be folding the early=20
refected field onto the direct field,


Please describe this physical phenomenon you call "folding the early reflec=
ted field onto the direct field." never heard of "folding sound." what is t=
hat? Never heard of a "reflected field." what is that? Never heard of a "di=
rect field." what is that?=20

destroying the spaciousness that was=20
recorded. It will sound like double mono.


I can assure you that an excellent playback system played in a well damped =
listening room using well recorded minimalist recordings sounds nothing lik=
e mono (not really sure what "double mono" is) And that such an arrangement=
not only will provide a tremendous sense of imaging and spaciousness but w=
ill actually provide more of it than one would get from the actual sound of=
live aocustic music in a concert hall. And that is a good thing since we n=
eed it to compensate for the lack of visual cues present at a concert and o=
ur inability to move our heads to better perceive aural imaging and spaciou=
sness at an actual concert.

All of this should have been=20
obvious to you after a certain number of years of listening to speakers o=

f=20
various radiation patterns. Can you hear differences among box speakers,=

=20
dipoles, bipoles, omnis? Good. Those differences are caused by difference=

s=20
in the image model, or reflection patterns and strengths, among those=20
speakers. Study that for a while.
=20

After years of listening I would say the opposite has become quite obvious =
to me

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Gary Eickmeier Gary Eickmeier is offline
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Posts: 1,449
Default The Problem with Stereo

Scott wrote:
On Monday, July 4, 2016 at 2:57:58 PM UTC-7, Gary Eickmeier wrote:


All of this should have been
obvious to you after a certain number of years of listening to
speakers of various radiation patterns. Can you hear differences
among box speakers, dipoles, bipoles, omnis? Good. Those differences
are caused by differences in the image model, or reflection patterns
and strengths, among those speakers. Study that for a while.

After years of listening I would say the opposite has become quite
obvious to me


Scott I can see you are an expert, and have no more learning to do. But just
as a thought experiment, see if you can imagine this one:

Let's go to a good, small community hall and have some musicians in and also
the finest stereo speakers you ever heard. The musicians are placed in the
normal manner, near the front of the room and arranged left to right at a
little distance from the walls. Place the speakers wherever you wish, but I
would suggest at about the 1/4 of the room width point and also about a
couple of feet in front of the band.

The band plays, you listen in the best seat in the house. The acoustics are
pretty darned good, and you hear the direct sound, the early reflected, and
a little of the reverberant. Good vibes, good music, great spacial qualities
in the room. We record this performance in stereo.

Now the band leaves and all go home, and we are going to play back the
recording of them. But wait - being good old standard old school
audiophiles, we have to do a little room treatment here - can't have all of
those reflections coming back twice and muddying up the sound. So let's just
imagine some Sonex or such all over the front and some of the side walls,
the speakers still there where they were in the stereo position.

So now we play all of this sound back again. So now all of the sound that
was recorded of this huge, spacious early reflected and reverberant field
will be coming from just those two points where the speakers are. You will
perceive the left and right most instruments and some of the in between
ones, spread evenly across the region between the speakers.

But will this high direct field from those two points in space sound the
same as the live sound that was recorded? Why or why not?

Gary Eickmeier

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Scott[_6_] Scott[_6_] is offline
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Posts: 642
Default The Problem with Stereo

On Wednesday, July 6, 2016 at 3:45:38 PM UTC-7, Gary Eickmeier wrote:
Scott wrote:
On Monday, July 4, 2016 at 2:57:58 PM UTC-7, Gary Eickmeier wrote:

=20
All of this should have been
obvious to you after a certain number of years of listening to
speakers of various radiation patterns. Can you hear differences
among box speakers, dipoles, bipoles, omnis? Good. Those differences
are caused by differences in the image model, or reflection patterns
and strengths, among those speakers. Study that for a while.

After years of listening I would say the opposite has become quite
obvious to me

=20
Scott I can see you are an expert, and have no more learning to do. But j=

ust=20
as a thought experiment, see if you can imagine this one:


If all ya got is condensending jabs and thought experiements that can lead =
to whatever conclusion we want since it happens in our heads I think we mig=
ht be done. But for giggles and kicks I feel like deconstructing this thoug=
ht experiment since it is plagued by all kinds of problems.=20

=20
Let's go to a good, small community hall and have some musicians in and a=

lso=20
the finest stereo speakers you ever heard. The musicians are placed in th=

e=20
normal manner, near the front of the room and arranged left to right at a=

=20
little distance from the walls.


In the concert halls I go to this is not how musicians are typically placed=
..=20

Place the speakers wherever you wish, but I=20
would suggest at about the 1/4 of the room width point and also about a=

=20
couple of feet in front of the band.


Speaker placement is very dependent on speaker design. No such generalized =
speaker placement will be ideal.=20

=20
The band plays, you listen in the best seat in the house.



What is "the best seat in the house?" Different seats often offer different=
qualities and trade offs.=20

The acoustics are=20
pretty darned good, and you hear the direct sound, the early reflected, a=

nd=20
a little of the reverberant. Good vibes, good music, great spacial qualit=

ies=20
in the room. We record this performance in stereo.


What technique is used for the recording? How is it monitored. What mics ar=
e used? What recorder? All these things affect the recording. You can't jus=
t make a non descript stereo recording. Recording profoundly affects what y=
ou hear in playback.


=20
Now the band leaves and all go home, and we are going to play back the=20
recording of them. But wait - being good old standard old school=20
audiophiles, we have to do a little room treatment here - can't have all =

of=20
those reflections coming back twice and muddying up the sound. So let's j=

ust=20
imagine some Sonex or such all over the front and some of the side walls,=

=20
the speakers still there where they were in the stereo position.


That would be a terrible application of room treatment. If that is the jist=
of your experience with room treatment that would explain a lot about you =
not liking it. Of course a little sonex, even a lot of sonex will not turn =
a good concert hall into a good stereo playback space. If it's a good conce=
rt hall it's going to be bad for the playback regardless of the use of sone=
x.=20


=20
So now we play all of this sound back again. So now all of the sound that=

=20
was recorded of this huge, spacious early reflected and reverberant field=

=20
will be coming from just those two points where the speakers are.


No, some sonex hardly makes a concert hall into an anechoic chamber.=20

You will=20
perceive the left and right most instruments and some of the in between=

=20
ones, spread evenly across the region between the speakers.


Maybe, who knows. I guess since this is a thought experiment we can say wha=
tever we want.=20
=20
But will this high direct field from those two points in space sound the=

=20
same as the live sound that was recorded? Why or why not?


Of course not, with or without the sonex. It won't sound the same because t=
he source of the sound will be completey different. Instead of musicians pl=
aying instruments in the hall making the sound you will have two speakers p=
laying back some, as of now undescribed, recording made in that space. Does=
n't matter if you damp the hall or not. It will sound nothing like the orig=
inal from the same designated alleged best seat.=20




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Peter Wieck Peter Wieck is offline
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Posts: 2,418
Default The Problem with Stereo

On Wednesday, July 6, 2016 at 6:45:38 PM UTC-4, Gary Eickmeier wrote:
es, spread evenly across the region between the speakers.
=20
But will this high direct field from those two points in space sound the=

=20
same as the live sound that was recorded? Why or why not?


Gary:

AR did this for years, and years, and years, using their 3 and 3a speakers,=
and had some of the finest golden-ears of the industry agreeing that the t=
ransition from speaker to live was seamless and transparent. This is exactl=
y the wrong suggestion to make as there are any number of speakers out ther=
e capable of that task. ONE THING!! They never would have been placed per y=
our suggestion, that would have been an invitation to failure. I suggest yo=
u go back in time and look for an AR white paper on how to place speakers i=
n any given room - all other things being equal. The surprises you will dis=
cover:

a) Speakers are not to be placed on the short wall of a room.
b) Speakers are placed some distance from a wall, corner or from the floor =
based on a number of factors determined by the room, its size and the natur=
e of the furnishings. This *WILL* vary.=20
c) No sort of additional 'enhancement' or 'deadening' or absorption is nece=
ssary. In other words, pretty basic placement per some pretty basic princip=
les is all that is necessary for excellent performance and a clean sound-st=
age (which is definitely larger than a human head in height, width and dept=
h).=20

I think you are confused by the size of your listening venue and the additi=
onal complexities that adds to the process.=20

Peter Wieck
Melrose Park, PA =20



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Gary Eickmeier Gary Eickmeier is offline
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Posts: 1,449
Default The Problem with Stereo

Peter Wieck wrote:
On Wednesday, July 6, 2016 at 6:45:38 PM UTC-4, Gary Eickmeier wrote:
es, spread evenly across the region between the speakers.

But will this high direct field from those two points in space sound
the same as the live sound that was recorded? Why or why not?


Gary:

AR did this for years, and years, and years, using their 3 and 3a
speakers, and had some of the finest golden-ears of the industry
agreeing that the transition from speaker to live was seamless and
transparent. This is exactly the wrong suggestion to make as there
are any number of speakers out there capable of that task. ONE
THING!! They never would have been placed per your suggestion, that
would have been an invitation to failure. I suggest you go back in
time and look for an AR white paper on how to place speakers in any
given room - all other things being equal. The surprises you will
discover:

a) Speakers are not to be placed on the short wall of a room.
b) Speakers are placed some distance from a wall, corner or from the
floor based on a number of factors determined by the room, its size
and the nature of the furnishings. This *WILL* vary.
c) No sort of additional 'enhancement' or 'deadening' or absorption
is necessary. In other words, pretty basic placement per some pretty
basic principles is all that is necessary for excellent performance
and a clean sound-stage (which is definitely larger than a human head
in height, width and depth).

I think you are confused by the size of your listening venue and the
additional complexities that adds to the process.

Peter Wieck
Melrose Park, PA


Yes I know all about the AR experiments/ demos. It was just a string quartet
and it was recorded anechoically so that the playback room would act the
same on the speakers as it did on the live instruments. I have a copy of one
of their recordings. It was a great effort and I respect what they did, but
I can't help but wonder how it would fare today. I mean, people thought the
first Edison recorders sounded just like real.

The most real sounding playback I have heard has been in a larger auditorium
with the speakers sitting on an actual stage and playing away in stereo. One
occasion in particular was a stage magician act that used recorded sound
rather than a pit orchestra. He had two stacks of Bose 802s on each side.
When you walked in you could swear it was live music, and the reason is that
the actual room acoustics swamped whatever recorded acoustic there may have
been. So it sounded just exactly like real instruments playing in that
acoustic space.

Stereo is an acoustical process, not an "accuracy" paradigm where the object
is to get the two channels to your two ears intact, with no distortions or
room effects. To address this acoustic part of the deal, you need to study
live sound and think of it as the mainly 3 fields, the direct, early
reflected, and reverberant. If you don't physically reconstruct those fields
in the same proportions and spatial shapes in your playback, or as near as
physically possible, it will sound different from live, and different from
the sound on that recording. I am using a shaped radiation pattern that puts
out 6 dB more toward the rear than toward the front of the speakers. This
extra output energizes the early reflected field in a shape that is similar
to a typical live one, going out 45 degrees from the center line of the
speaker to bounce and fill the center and go out and back from the corner
bounce to arrive from spatially similar angles to the live situation. The
extra output causes an image shift toward the reflecting surfaces, causing
an auditory event of greater depth and spaciousness with the instruments
forming an aerial image in a plane behind the speakers, the speakers
disappearing completely as sources themselves. The speaker placement ensures
that the imaging is very even all across the front of the room, and
individual images seem like they are acoustic sources right in your room,
not coming from two megaphones, so to speak. There is no combing because the
front and rear outputs are not equal; there is no hole in the middle or
clustering of reflections or stretched soloists because of the speaker
placement, extremely important for speakers with a high reflected field.
All of these factors are interrelated and very important to the total
effect, such that if you got the radiation pattern right but screwed up the
speaker positioning, you would not observe the same effect. If you place
your speakers correctly, but they don't have anything going to the rear, the
soundstage will not "set up."

Very unlikely that experimenters or speaker companies out there would
stumble upon these highly contrarian principles all at once, so I go on
preaching to see if it might spark someone's imagination. The big picture is
that you do this image modeling for the frontal soundstage and you support
the reverberant field with some surround speakers. And yes, the room is a
good part of the deal, with acoustical properties for the reflected sound
and the larger the room the more like the size of the real thing.

Finally, as for the main objection to such a technique, we are NOT doubling
up the acoustic that was recorded because there is not a substantial
reverberant field in most domestic sized listening rooms. The single
reflection that I am using to construct the shape of the reflected field
does not make an acoustic signature, and you can absorb a lot of it as you
go back in the room with thick carpeting and normal stuffed furniture so
that you have no slap echo returning if you clap your hands. So - you have
not changed the temporal, just the spatial to make it resemble the real
thing more closely - physically - acoustically - within your room on
playback.

The speakers are then seen not as direct radiators but rather as Image Model
Projectors.

Gary Eickmeier

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Scott[_6_] Scott[_6_] is offline
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Posts: 642
Default The Problem with Stereo

On Wednesday, July 6, 2016 at 6:58:28 PM UTC-7, Peter Wieck wrote:
On Wednesday, July 6, 2016 at 6:45:38 PM UTC-4, Gary Eickmeier wrote:
es, spread evenly across the region between the speakers.
=20
But will this high direct field from those two points in space sound th=

e=20
same as the live sound that was recorded? Why or why not?

=20
Gary:
=20
AR did this for years, and years, and years, using their 3 and 3a speaker=

s, and had some of the finest golden-ears of the industry agreeing that the=
transition from speaker to live was seamless and transparent. This is exac=
tly the wrong suggestion to make as there are any number of speakers out th=
ere capable of that task. ONE THING!! They never would have been placed per=
your suggestion, that would have been an invitation to failure. I suggest =
you go back in time and look for an AR white paper on how to place speakers=
in any given room - all other things being equal. The surprises you will d=
iscover:
=20
a) Speakers are not to be placed on the short wall of a room.
b) Speakers are placed some distance from a wall, corner or from the floo=

r based on a number of factors determined by the room, its size and the nat=
ure of the furnishings. This *WILL* vary.=20
c) No sort of additional 'enhancement' or 'deadening' or absorption is ne=

cessary. In other words, pretty basic placement per some pretty basic princ=
iples is all that is necessary for excellent performance and a clean sound-=
stage (which is definitely larger than a human head in height, width and de=
pth).=20
=20
I think you are confused by the size of your listening venue and the addi=

tional complexities that adds to the process.=20
=20
Peter Wieck
Melrose Park, PA


Pretty sure AR did this with a string quartet, always in an overly reverber=
ant room with a lot of people witnessing the comaprison and...musicians tha=
t did a great job of keeping up the visual cues of musicians playing when t=
hey would switch to playback. One deos not hear much if any seperation of i=
nstruments with a string quartet from any substantial distance particularly=
in an overly reverberant room. So it would not be the least bit surprising=
that a single speaker would image quite in a similar fashion, especially w=
ith the visual cues in place of actual musicians playing.
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Peter Wieck Peter Wieck is offline
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Posts: 2,418
Default The Problem with Stereo

On Thursday, July 7, 2016 at 7:10:33 AM UTC-4, Scott wrote:

Pretty sure AR did this with a string quartet, always in an overly reverb=

erant room with a lot of people witnessing the comaprison and...musicians t=
hat did a great job of keeping up the visual cues of musicians playing when=
they would switch to playback. One deos not hear much if any seperation of=
instruments with a string quartet from any substantial distance particular=
ly in an overly reverberant room. So it would not be the least bit surprisi=
ng that a single speaker would image quite in a similar fashion, especially=
with the visual cues in place of actual musicians playing.


Gary & Scott:

I think that at this point, we may be at cross-purposes. Stereo (however it=
is defined after the word alone is written) is a compromise of many facets=
, much as an elephant is a mouse to Government Specifications (both grey, l=
arge-eared, bare-tailed mammals) or a camel is a horse designed by a commit=
tee (Camels are mean beasts, spit further and harder than Llamas, are moody=
, and not very cooperative. Racing, riding and war camels are mostly female=
- males are bred for size, fighting (each other) and meat). Facets include=
recording technique, engineering, mixing, number and placement of micropho=
nes, analog or digital, the venue (an orchestra recorded in an empty hall w=
ith infinite repeats if a mistake is made will not be the same as a so-call=
ed "live" recording), the playback system(s), how many mechanical steps (ju=
st microphone and speaker, or microphone, cutting lathe, stamped vinyl, sty=
lus, cartridge and speaker), and much more. And a lot has been learned sinc=
e the early days. Keep in mind that early receivers and pre-amps and integ=
rated amplifiers from some of the more thoughtful manufacturers had center-=
channel outputs as early recordings often so 'enhanced' stereo effects as t=
o make the "dual mono" almost a reality. It was almost the case where the p=
roverbial left-hand had no knowledge or interaction with the right.

The average listener has neither the time, treasure or even the inclination=
to invest heroic amounts in their listening venue, and often enough, their=
entire budget for a playback system is less than the cost (new) of one pai=
r of my better speakers - and they are 'cheap' relative to what can be spen=
t. To expect that the average listener/hobbyist, even one quite serious abo=
ut it, to do so is not realistic.=20

Further, should the industry actually attempt to address the issues raised =
here head-on using a solution such as Gary describer, they would, effective=
ly, be putting sound reproduction out of the reach of all but the most well=
-heeled.=20

There are problems with stereo that may be discernible to a few under speci=
al conditions and if a direct comparison to a live performance is available=
.. Otherwise, if the sound heard is pleasing - that should be enough, as no =
amount of brute force or subtle nudging will make electronic playback the a=
udible equivalent to unreinforced live performance - especially if the play=
back venue is not the exact funcional equivalent of the performance venue.=
=20

Peter Wieck
Melrose Park, PA=20
  #24   Report Post  
Posted to rec.audio.high-end
Gary Eickmeier Gary Eickmeier is offline
external usenet poster
 
Posts: 1,449
Default The Problem with Stereo

Peter Wieck wrote:

Gary & Scott:

I think that at this point, we may be at cross-purposes. Stereo
(however it is defined after the word alone is written) is a
compromise of many facets, much as an elephant is a mouse to
Government Specifications (both grey, large-eared, bare-tailed
mammals) or a camel is a horse designed by a committee (Camels are
mean beasts, spit further and harder than Llamas, are moody, and not
very cooperative. Racing, riding and war camels are mostly female -
males are bred for size, fighting (each other) and meat). Facets
include recording technique, engineering, mixing, number and
placement of microphones, analog or digital, the venue (an orchestra
recorded in an empty hall with infinite repeats if a mistake is made
will not be the same as a so-called "live" recording), the playback
system(s), how many mechanical steps (just microphone and speaker, or
microphone, cutting lathe, stamped vinyl, stylus, cartridge and
speaker), and much more. And a lot has been learned since the early
days. Keep in mind that early receivers and pre-amps and integrated
amplifiers from some of the more thoughtful manufacturers had
center-channel outputs as early recordings often so 'enhanced' stereo
effects as to make the "dual mono" almost a reality. It was almost
the case where the proverbial left-hand had no knowledge or
interaction with the right.

The average listener has neither the time, treasure or even the
inclination to invest heroic amounts in their listening venue, and
often enough, their entire budget for a playback system is less than
the cost (new) of one pair of my better speakers - and they are
'cheap' relative to what can be spent. To expect that the average
listener/hobbyist, even one quite serious about it, to do so is not
realistic.

Further, should the industry actually attempt to address the issues
raised here head-on using a solution such as Gary describer, they
would, effectively, be putting sound reproduction out of the reach of
all but the most well-heeled.

There are problems with stereo that may be discernible to a few under
special conditions and if a direct comparison to a live performance
is available. Otherwise, if the sound heard is pleasing - that should
be enough, as no amount of brute force or subtle nudging will make
electronic playback the audible equivalent to unreinforced live
performance - especially if the playback venue is not the exact
funcional equivalent of the performance venue.

Peter Wieck
Melrose Park, PA


Thanks again Peter and Scott -

.....and what you say Peter is partially true, but not entirely. What IS a
shame is the extent to which the bull****ters and maketeers have been able
to take over the industry and sell those well-heeled audiophiles crap that
is either not right or a lie or costs more than it is worth or based on
wrong technology. Like religious evangelicals these audiophiles will believe
ANYTHING and pay any amount to get good sound.

My speakers cost me about $1500 each to have built, and that doesn't really
repay him for his experience and insights into helping me achieve my goals
with them. They are very sophisticated designs even outside the purpose for
which they were built, the radiation pattern. In addition to the pattern
they are built as bi-amped or not, you choose, so that experimenters could
amplify each half independently to vary the gains and see what happens to
the sound imaging. That plus there are two pots on top of the speaker to
vary the ratio between the two front driver faces, to adjust the distance/
intensity trading to keep the imaging centered as you walk across the room.
That works very well too.Very similar to Mark Davis's Soundfield One.

But what I am about is to explain the problem with traditional stereo theory
and try to correct it. Image Model Theory is just a more visual way of
looking at the big picture of radiation pattern, speaker positioning, and
room acoustics. You draw the first reflections as additional sources on the
other side of the wall and study the patterns of reflected sound that this
technique shows. Then you have to understand stereo as an acoustical
process, not a head-related process with two ears, two speakers fooling you
into hearing stereo. At this stage in the history of reproduced sound, we
should not be making most speakers with all of the drivers on the front and
whatever radiation pattern they put out being accidental rather than
designed in. Allison, Toole, Davis, and a few others realize that the radpat
should be wide and smooth and the freq response equi-omni in order to get
the first reflections to have the same response as the actual speakers. But
none of them have studied how the room positioning affects the total image,
or that there needs to be more output to the rear, or what kind of
reflectivity you need to set up the total frontal soundstage. In other
words, with correct theory on how to put the sound into the room all of that
expensive equipment should not be necessary and we could all be enjoying our
precious music so much more.

I will try and come up with a paper for the next NY convention. Not sure I
could transport the sound of my room to a hotel room by bringing the
speakers up there, but it would be great if I could do that and it really
worked well. Anyway, if you get up there look for a paper called "Image
Model Theory 30 Years On."

Gary

  #25   Report Post  
Posted to rec.audio.high-end
Gary Eickmeier Gary Eickmeier is offline
external usenet poster
 
Posts: 1,449
Default The Problem with Stereo

Peter Wieck wrote:

Gary & Scott:

I think that at this point, we may be at cross-purposes. Stereo
(however it is defined after the word alone is written) is a
compromise of many facets, much as an elephant is a mouse to
Government Specifications (both grey, large-eared, bare-tailed
mammals) or a camel is a horse designed by a committee (Camels are
mean beasts, spit further and harder than Llamas, are moody, and not
very cooperative. Racing, riding and war camels are mostly female -
males are bred for size, fighting (each other) and meat). Facets
include recording technique, engineering, mixing, number and
placement of microphones, analog or digital, the venue (an orchestra
recorded in an empty hall with infinite repeats if a mistake is made
will not be the same as a so-called "live" recording), the playback
system(s), how many mechanical steps (just microphone and speaker, or
microphone, cutting lathe, stamped vinyl, stylus, cartridge and
speaker), and much more. And a lot has been learned since the early
days. Keep in mind that early receivers and pre-amps and integrated
amplifiers from some of the more thoughtful manufacturers had
center-channel outputs as early recordings often so 'enhanced' stereo
effects as to make the "dual mono" almost a reality. It was almost
the case where the proverbial left-hand had no knowledge or
interaction with the right.

The average listener has neither the time, treasure or even the
inclination to invest heroic amounts in their listening venue, and
often enough, their entire budget for a playback system is less than
the cost (new) of one pair of my better speakers - and they are
'cheap' relative to what can be spent. To expect that the average
listener/hobbyist, even one quite serious about it, to do so is not
realistic.

Further, should the industry actually attempt to address the issues
raised here head-on using a solution such as Gary describer, they
would, effectively, be putting sound reproduction out of the reach of
all but the most well-heeled.

There are problems with stereo that may be discernible to a few under
special conditions and if a direct comparison to a live performance
is available. Otherwise, if the sound heard is pleasing - that should
be enough, as no amount of brute force or subtle nudging will make
electronic playback the audible equivalent to unreinforced live
performance - especially if the playback venue is not the exact
funcional equivalent of the performance venue.

Peter Wieck
Melrose Park, PA


Thanks again Peter and Scott -

.....and what you say Peter is partially true, but not entirely. What IS a
shame is the extent to which the bull****ters and maketeers have been able
to take over the industry and sell those well-heeled audiophiles crap that
is either not right or a l ie or costs more than it is worth or based on
wrong technology. Like religious evangelicals these audiophiles will believe
ANYTHING and pay any amount to get good sound.

My speakers cost me about $1500 each to have built, and that doesn't really
repay him for his experience and insights into helping me achieve my goals
with them. They are very sophisticated designs even outside the purpose for
which they were built, the radiation pattern. In addition to the pattern
they are built as bi-amped or not, you choose, so that experimenters could
amplify each half independently to vary the gains and see what happens to
the sound imaging. That plus there are two pots on top of the speaker to
vary the ratio between the two front driver faces, to adjust the distance/
intensity trading to keep the imaging centered as you walk across the room.
That works very well too.Very similar to Mark Davis's Soundfield One.

But what I am about is to explain the problem with traditional stereo theory
and try to correct it. Image Model Theory is just a more visual way of
looking at the big picture of radiation pattern, speaker positioning, and
room acoustics. You draw the first reflections as additional sources on the
other side of the wall and study the patterns of reflected sound that this
technique shows. Then you have to understand stereo as an acoustical
process, not a head-related process with two ears, two speakers fooling you
into hearing stereo. At this stage in the history of reproduced sound, we
should not be making most speakers with all of the drivers on the front and
whatever radiation pattern they put out being accidental rather than
designed in. Allison, Toole, Davis, and a few others realize that the radpat
should be wide and smooth and the freq response equi-omni in order to get
the first reflections to have the same response as the actual speakers. But
none of them have studied how the room positioning affects the total image,
or that there needs to be more output to the rear, or what kind of
reflectivity you need to set up the total frontal soundstage. In other
words, with correct theory on how to put the sound into the room all of that
expensive equipment should not be necessary and we could all be enjoying our
precious music so much more.

I will try and come up with a paper for the next NY convention. Not sure I
could transport the sound of my room to a hotel room by bringing the
speakers up there, but it would be great if I could do that and it really
worked well. Anyway, if you get up there look for a paper called "Image
Model Theory 30 Years On."

Gary



  #26   Report Post  
Posted to rec.audio.high-end
Scott[_6_] Scott[_6_] is offline
external usenet poster
 
Posts: 642
Default The Problem with Stereo

On Friday, July 8, 2016 at 4:26:19 AM UTC-7, Gary Eickmeier wrote:
Peter Wieck wrote:
=20
Gary & Scott:

I think that at this point, we may be at cross-purposes. Stereo
(however it is defined after the word alone is written) is a
compromise of many facets, much as an elephant is a mouse to
Government Specifications (both grey, large-eared, bare-tailed
mammals) or a camel is a horse designed by a committee (Camels are
mean beasts, spit further and harder than Llamas, are moody, and not
very cooperative. Racing, riding and war camels are mostly female -
males are bred for size, fighting (each other) and meat). Facets
include recording technique, engineering, mixing, number and
placement of microphones, analog or digital, the venue (an orchestra
recorded in an empty hall with infinite repeats if a mistake is made
will not be the same as a so-called "live" recording), the playback
system(s), how many mechanical steps (just microphone and speaker, or
microphone, cutting lathe, stamped vinyl, stylus, cartridge and
speaker), and much more. And a lot has been learned since the early
days. Keep in mind that early receivers and pre-amps and integrated
amplifiers from some of the more thoughtful manufacturers had
center-channel outputs as early recordings often so 'enhanced' stereo
effects as to make the "dual mono" almost a reality. It was almost
the case where the proverbial left-hand had no knowledge or
interaction with the right.

The average listener has neither the time, treasure or even the
inclination to invest heroic amounts in their listening venue, and
often enough, their entire budget for a playback system is less than
the cost (new) of one pair of my better speakers - and they are
'cheap' relative to what can be spent. To expect that the average
listener/hobbyist, even one quite serious about it, to do so is not
realistic.

Further, should the industry actually attempt to address the issues
raised here head-on using a solution such as Gary describer, they
would, effectively, be putting sound reproduction out of the reach of
all but the most well-heeled.

There are problems with stereo that may be discernible to a few under
special conditions and if a direct comparison to a live performance
is available. Otherwise, if the sound heard is pleasing - that should
be enough, as no amount of brute force or subtle nudging will make
electronic playback the audible equivalent to unreinforced live
performance - especially if the playback venue is not the exact
funcional equivalent of the performance venue.

Peter Wieck
Melrose Park, PA

=20
Thanks again Peter and Scott -
=20
....and what you say Peter is partially true, but not entirely. What IS a=

=20
shame is the extent to which the bull****ters and maketeers have been abl=

e=20
to take over the industry and sell those well-heeled audiophiles crap tha=

t=20
is either not right or a lie or costs more than it is worth or based on=

=20
wrong technology. Like religious evangelicals these audiophiles will beli=

eve=20
ANYTHING and pay any amount to get good sound.
=20
My speakers cost me about $1500 each to have built, and that doesn't real=

ly=20
repay him for his experience and insights into helping me achieve my goal=

s=20
with them. They are very sophisticated designs even outside the purpose f=

or=20
which they were built, the radiation pattern. In addition to the pattern=

=20
they are built as bi-amped or not, you choose, so that experimenters coul=

d=20
amplify each half independently to vary the gains and see what happens t=

o=20
the sound imaging. That plus there are two pots on top of the speaker to=

=20
vary the ratio between the two front driver faces, to adjust the distance=

/=20
intensity trading to keep the imaging centered as you walk across the roo=

m.=20
That works very well too.Very similar to Mark Davis's Soundfield One.
=20
But what I am about is to explain the problem with traditional stereo the=

ory=20
and try to correct it. Image Model Theory is just a more visual way of=20
looking at the big picture of radiation pattern, speaker positioning, and=

=20
room acoustics. You draw the first reflections as additional sources on t=

he=20
other side of the wall and study the patterns of reflected sound that thi=

s=20
technique shows. Then you have to understand stereo as an acoustical=20
process, not a head-related process with two ears, two speakers fooling y=

ou=20
into hearing stereo. At this stage in the history of reproduced sound, we=

=20
should not be making most speakers with all of the drivers on the front a=

nd=20
whatever radiation pattern they put out being accidental rather than=20
designed in. Allison, Toole, Davis, and a few others realize that the rad=

pat=20
should be wide and smooth and the freq response equi-omni in order to get=

=20
the first reflections to have the same response as the actual speakers. B=

ut=20
none of them have studied how the room positioning affects the total imag=

e,=20
or that there needs to be more output to the rear, or what kind of=20
reflectivity you need to set up the total frontal soundstage. In other=20
words, with correct theory on how to put the sound into the room all of t=

hat=20
expensive equipment should not be necessary and we could all be enjoying =

our=20
precious music so much more.
=20
I will try and come up with a paper for the next NY convention. Not sure =

I=20
could transport the sound of my room to a hotel room by bringing the=20
speakers up there, but it would be great if I could do that and it really=

=20
worked well. Anyway, if you get up there look for a paper called "Image=

=20
Model Theory 30 Years On."
=20
Gary


The basic problem with trying to change how stereo works is that you have t=
wo components to stereo, playback and recordings. We can do what we want an=
d try different things with playback. But we can't change the 60+ year host=
ory of stereo recordings and how they were done. And we can't change the fa=
ct that they were done quite differently over the years. There are better w=
ays to create the illusion of realism than conventional stereo recording an=
d playback. The problem is that you exclude all of the great music=20
recorded in stereo over it's 60+ year history. And that ultimately defeats =
the purpose for most of us. So we are stuck with a technology that is all o=
ver the map when it comes to source material and all over the map when it c=
omes to finding our most prefered way to play that source material back. Yo=
u have found your favorite solution and I have found mine and they are quit=
e different. But there is no objective right or wrong here. It is about pre=
ferences and what one finds the most pleasing.
  #27   Report Post  
dolph dolph is offline
Junior Member
 
Posts: 11
Default

If your room is untreated it adds its own
reflections.
192.168.l.2

Last edited by dolph : September 6th 16 at 01:19 PM
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