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Robert Peirce Robert Peirce is offline
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Default Need advice for a small room

For me, stereo is about the imaging. I can't tell if my room is down
3db at 400hz, and frankly, I don't care as long as it sounds good. I
don't even go in for room treatment of any sort. Every room, including
a concert hall is going to have peaks and dips. I just live with that.

Right now I have a pair of Apogee Divas in a room that is about
15.5'x25'. Maybe I just got lucky, but I can walk just about anywhere
in the room and the image is locked in place. The only place this fails
is if I stand within a foot directly in front of one of the speakers.

I am planning to move and most of the rooms I am looking at tend to be
on the order of 10-12'. Sometimes they are almost square. I was all
hyped up on one product as a possibility for such a room until I found
out it was more about getting correct response from the room then the
kind of imaging I am after.

So, are there any imaging nuts out there who are dealing successfully
with small rooms? What are you doing?

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Audio Empire Audio Empire is offline
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Default Need advice for a small room

On Thu, 26 Apr 2012 11:45:01 -0700, ScottW wrote
(in article ):

On Apr 26, 6:23=A0am, Robert Peirce wrote:
For me, stereo is about the imaging. =A0I can't tell if my room is down
3db at 400hz, and frankly, I don't care as long as it sounds good. I
don't even go in for room treatment of any sort. =A0Every room, including
a concert hall is going to have peaks and dips. =A0I just live with that.

Right now I have a pair of Apogee Divas in a room that is about
15.5'x25'. =A0Maybe I just got lucky, but I can walk just about anywhere
in the room and the image is locked in place. =A0The only place this fail=

s
is if I stand within a foot directly in front of one of the speakers.

I am planning to move and most of the rooms I am looking at tend to be
on the order of 10-12'. =A0Sometimes they are almost square. =A0I was all
hyped up on one product as a possibility for such a room until I found
out it was more about getting correct response from the room then the
kind of imaging I am after.

So, are there any imaging nuts out there who are dealing successfully
with small rooms? =A0What are you doing?


I find some of your comments contradictory to my experience.
Imaging, IME, is somewhat inversely proportional to sweet spot size.
Speakers that offer an image that doesn't change much around the room
might be satisfactory for you, but have not offered to me that
pinpoint image precision in the sweet spot which can be quite beyond
realistic.
Best imaging speakers I ever owned were Quad 63's with a sweet spot
about the size of a cubic foot. As dipolars they need some space
behind them and even then benefit from a rear wave diffuser (I
fabricated a device similar to Soundlabs Sallie) for peak image
clarity. But I don't think they (or any dipolar) will work well at
all in a 12' room.

For a small room I'd explore some decent bookshelfs with a sub. I
heard some Spendor S3s in a small room at a dealer once with a Hsu sub
that I thought really lacked nothing except the ability to drive a
large room. Imaging was excellent and the separate sub allowed you to
position and contour the bass to what the room could handle. Full
range speakers forcing you to basically co-locate the bass drivers
with the mid/hi freq sources creates an insurmountable problem and
usually costs more as well.

ScottW


I agree that most speakers image properly only in a fairly small "sweet
spot". That spot is usually the locus of the pick-up of the stereo pair of
microphones used, and there is only one for each recording.

One of the things about stereo recordings (and this is something that most
audiophiles never think about) that differs from a live performance is that
when you are there at a performance and move around from place to place, the
stereo perspective moves with your ears. When listening to a recording, this
does not happen because even though YOU move, your "surrogate ears" (the
microphones) do not. They maintain the same perspective in the space where
the recording was made and don't move with you. That's why the only place
where the imaging is best is when you, the listener, are located in the
acoustic focal point of the microphones. I could illustrate what I mean with
a diagram, but I don't believe that graphics are supported on bulletin boards
such as this one.

Of course, what I just said presupposes a REAL stereo recording, not some
multi-miked fiasco where there is a forrest of microphones all pan-potted
into position and where the only "image" the recording has is of a bunch of
musicians lined up in a straight line from the left side of the sound-stage
to the right side.
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Robert Peirce Robert Peirce is offline
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Default Need advice for a small room

There is imaging and there is imaging. I relate what I want to hear to
what I actually do hear at a live performance.

From a reasonable distance, I can't exactly pick out that the bass is

here and the drums are there. They sort of merge together. I think it
is a function of the "included angle" of the performers from my
listening position. It is one thing if you are on stage, maybe in the
middle of the group. It is another thing if you are 50 or 100 feet back
in the hall.

I am trying to preserve the illusion of being back in the hall and I get
that from my Apogee Divas. The fact that the apparent image doesn't
shift much when I move about the room is a good thing. If I'm 100' from
the stage and I move a few seats one way or the other I am not going to
notice much difference and I am still going to have an image of the
group in pretty much the same place.

I am trying to translate that from a fairly large listening space, about
400 sq. ft., into something much smaller, about 140 sq. ft. I recognize
that small monitors can give me pin-point imaging from the sweet spot,
but that illusion is being much closer to the stage, perhaps on the
stage. I am after the back in the hall illusion and I need something
different for that. I just don't know what it is.

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Default Need advice for a small room

I can see I am running the risk of sounding like the guy from a few
weeks ago who denied the idea of a perfect amplifier in favor of his
euphonic preferences.

I don't deny the goal of perfect sound, which to me is live,
unamplified, music in a real space. I have even heard sound
reproduction that comes very close to that. My problem is every time I
have encountered those conditions they existed for a relatively small
space in the room. Move out of that space and the soundstage collapsed.

My problem is I do not have a dedicated music room for one person. My
space is multi-purpose. I have a small sofa, which I guess, is the
prime listening spot. However, I also have a desk and chair a few feet
behind the sofa which is where I spend a lot of my time. Sometimes I
have a few friends over to listen to music, drink a little wine, wonder
around the room and chat. One time I even rolled up the rug, moved the
furniture and turned the space into a small ballroom for about 30 people.

In all those cases I had the illusion of a live group at the front of
the room. The sound wouldn't stand up to critical listening from the
sweet spot, but it was very good sound for everybody and that is what I
am after, except the space will be about 150' instead of 400'.

For a while I was very enthusiastic about the Steinway-Lyngdorf system,
as described recently in TAS. The idea of tuning a smaller, possibly
odd-shaped, room sounded very good. Then I discovered they don't
actually tune the room. The tune the sweet spot. I'm sure the sound in
that spot is just wonderful, but what is it like a few feet away?

Because of my experience with the Apogee planar speakers, I am now
thinking something from Magnepan might work. They even have a speaker
designed o mount on the wall, which makes a lot of sense for a very
small room.

However, I don't want to limit myself, but I don't want to go the sweet
spot route either. Therefore, I am open to suggestions from people who
have first-hand experience in this area, but under the circumstances, I
cannot be interested in the comments of people who just want to tell me
how wrong I am and what I should really be doing to get perfect sound
forever.
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Andrew Haley Andrew Haley is offline
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Robert Peirce wrote:

Therefore, I am open to suggestions from people who have first-hand
experience in this area, but under the circumstances, I cannot be
interested in the comments of people who just want to tell me how
wrong I am and what I should really be doing to get perfect sound
forever.


I have a suggestion to make: Sound Reproduction: The Acoustics and
Psychoacoustics of Loudspeakers and Rooms by Floyd Toole. Beware of
anyone who tells you of easy solutions to this problem, but being
well-informed won't hurt.

Andrew.


http://www.amazon.com/Sound-Reproduc...dp/0240520092/



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Robert Peirce Robert Peirce is offline
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Default Need advice for a small room

In article ,
Andrew Haley wrote:

I have a suggestion to make: Sound Reproduction: The Acoustics and
Psychoacoustics of Loudspeakers and Rooms by Floyd Toole. Beware of
anyone who tells you of easy solutions to this problem, but being
well-informed won't hurt.

Andrew.


http://www.amazon.com/Sound-Reproduc...cs-Loudspeaker
s/dp/0240520092/


No doubt, but I lack the luxury of using some of the ideas spelled out
here. My current listening room was purpose built and has worked well.
Now I am in a situation where I will have to make do with what I can
find and I will be limited with what I can do with the space.

The room dimensions are unknown at this point, but they will be fairly
small. I will be forced to have only two (or four with separate woofers)
fairly small speakers near the front of the room and limited room
treatment beyond furniture and rugs. Yet I want to be able to hear a
decent soundstage from just about anywhere in the room. Given those
constraints, actual experience in solving this problem is likely to
prove more helpful.

Regardless of room constructions and shape, there are speakers that work
well if you are in a single position but not so well if you are not, and
speakers that possibly aren't the best for a fixed location but provide
good sound throughout the space. I'm not going to find that out from a
book. I could learn something by going around and listening, which is
what I did twenty years ago, but that has become almost impossibly
difficult today.

From experience, I am skeptical of most mini-monitors, yet I remember

the Spica speaker from years ago throwing a broad stable sound stage.
On the other extreme, large panel speakers like I have now can do the
job but they won't fit in a very small room. I am reasonably confident
others have the same goals I do and have solved, or at least made
inroads into, this problem.

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Robert Peirce wrote:
In article ,
Andrew Haley wrote:

I have a suggestion to make: Sound Reproduction: The Acoustics and
Psychoacoustics of Loudspeakers and Rooms by Floyd Toole. Beware of
anyone who tells you of easy solutions to this problem, but being
well-informed won't hurt.

http://www.amazon.com/Sound-Reproduc...dp/0240520092/


The room dimensions are unknown at this point, but they will be fairly
small. I will be forced to have only two (or four with separate woofers)
fairly small speakers near the front of the room and limited room
treatment beyond furniture and rugs. Yet I want to be able to hear a
decent soundstage from just about anywhere in the room. Given those
constraints, actual experience in solving this problem is likely to
prove more helpful.


Do you really think that actual experience from a few here will be
more helpful than Toole's book, which addresses this issue, and is
based on the largest body of research in this area? You may get
information about someone's room, but with no guarantee that it
applies to yours.

Regardless of room constructions and shape, there are speakers that
work well if you are in a single position but not so well if you are
not, and speakers that possibly aren't the best for a fixed location
but provide good sound throughout the space.


This is to do with the directivity of a loudspeaker and the way that
it interacts with a room. Many loudspeakers that have an excellent
frequency response on axis are very ragged off-axis. The most
desirable trait, from your point of view, is that the directivity of
your loudspeakers should be constant, or at least only gradually
changing, over most of the frequency range. Loudspeakers with higher
off-axis radiation will help. But -- and this is only my subjective
experience, based on a few examples -- some rooms will never sound
very good, no matter what you do.

I'm not going to find that out from a book.


But, strangely, you will find it out from Usenet!

Andrew.
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On Sat, 28 Apr 2012 15:23:55 -0700, Robert Peirce wrote
(in article ):

From experience, I am skeptical of most mini-monitors, yet I remember
the Spica speaker from years ago throwing a broad stable sound stage.
On the other extreme, large panel speakers like I have now can do the
job but they won't fit in a very small room. I am reasonably confident
others have the same goals I do and have solved, or at least made
inroads into, this problem.



Interesting comment. I have found that small monitors on good, sturdy stands
image better than most large speakers (the "infinitely small" sound-source
theory) when fed true stereophonic material (no, multi-miked, multi-track
recordings made with a forest of microphones with each instrument pan-potted
into place across the soundstage, or divided into three mono groups, right,
center, and left, don't qualify as stereo.) and I think the best imaging
speakers I ever heard were a pair of Rogers' LS3 "BBC monitors" that a friend
of mine once owned. They had no bass to speak of, but that's another story.

Big bipolar panel speakers throw a huge soundstage but they don't do image
specificity very well, in my experience. I have a pair of Martin-Logan
electrostatics now, and due to their curved surface, they act like a line
source at higher midrange and treble frequencies and they image pretty darn
well too, having some of the characteristics of the large panels (like
Maggies or Apogees) and some of the characteristics of small monitors.
They're not as good as those BBC monitors though. Of course, the imaging must
be on the recording for any speaker to reproduce it realistically. You'll not
get any imaging (especially image height and front-to-back depth) from any
rock/pop recording where the sound is totally a product of the studio, or
most jazz recordings where close-up miking and three-channel mono are the
order of the day.
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Robert Peirce Robert Peirce is offline
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Default Need advice for a small room

In article ,
Andrew Haley wrote:

Robert Peirce wrote:
In article ,
Andrew Haley wrote:

Regardless of room constructions and shape, there are speakers that
work well if you are in a single position but not so well if you are
not, and speakers that possibly aren't the best for a fixed location
but provide good sound throughout the space.


This is to do with the directivity of a loudspeaker and the way that
it interacts with a room. Many loudspeakers that have an excellent
frequency response on axis are very ragged off-axis. The most
desirable trait, from your point of view, is that the directivity of
your loudspeakers should be constant, or at least only gradually
changing, over most of the frequency range.


Thanks. I couldn't exactly describe the desired characteristics of the
speaker but I think that is pretty close. The panel speakers I have
probably aren't terribly directional, especially since half the sound is
bouncing of the front wall. The mini-monitors I have described as
working well only at a point are probably highly directional.

So, where does one find information on small, non-directional speakers
that can get down to, say, 25-30Hz, probably with the addition of
woofers?
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In article ,
Audio Empire wrote:

Big bipolar panel speakers throw a huge soundstage but they don't do image
specificity very well, in my experience.


Yes. That is what I am after. The image (Apogee Diva) isn't as
specific but it is very stable from many points in the room. On the
mini-monitors I have run into the image is great at one point but the
soundstage collapses if you get too far away from that point.

I like to listen from multiple locations in my current room and am
willing to trade-off really great sound at one point and nowhere else
for very good sound everywhere.

I am prepared to hear there are exceptions. For example, I have been
told the Steinway Lyngdorf S-series actually does this very well; I had
started to come to the conclusion it wouldn't. There are probably many
other small speakers of which I am unaware that also can serve my
purposes.

The key is very good sound everywhere at the expense of close to perfect
sound at one spot.



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On Mon, 30 Apr 2012 15:58:37 -0700, Robert Peirce wrote
(in article ):

In article ,
Andrew Haley wrote:

Robert Peirce wrote:
In article ,
Andrew Haley wrote:

Regardless of room constructions and shape, there are speakers
that work well if you are in a single position but not so well if
you are not, and speakers that possibly aren't the best for a
fixed location but provide good sound throughout the space.


This is to do with the directivity of a loudspeaker and the way
that it interacts with a room. Many loudspeakers that have an
excellent frequency response on axis are very ragged off-axis. The
most desirable trait, from your point of view, is that the
directivity of your loudspeakers should be constant, or at least
only gradually changing, over most of the frequency range.


Thanks. I couldn't exactly describe the desired characteristics of
the speaker but I think that is pretty close. The panel speakers I
have probably aren't terribly directional, especially since half the
sound is bouncing of the front wall. The mini-monitors I have
described as working well only at a point are probably highly
directional.

So, where does one find information on small, non-directional
speakers that can get down to, say, 25-30Hz, probably with the
addition of woofers?


With the addition of proper subwoofers, ANY small speakers will "get
down" to 25-30 Hz. The thing about small speakers is that price-wise,
they're all over the map. You can go for a pair of Magico Q1's
(approx. 14" X 14" X 9" - two way) for twenty-five THOUSAND dollars a
pair, to a pair of Usher "Tiny Dancer" 2-way for about $2,700 a pair
down to the similar (and also excellent) Monitor Audio BX1s at less
than $500/pair. Hint: The British are really good at making this type
of speaker and most British speaker brands have these small
stand-mounted speakers as part of their product lineup.

I have heard the Magicos, and they are magic, but I've also heard the
BX1s and they too are amazing for 1/50 the price with an on-axis
frequency response of 55 to 30KHz +/- 3 dB! But whatever you decide on
don't forget to budget for some decent stands.
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In article ,
Audio Empire wrote:

with an on-axis frequency response of 55 to 30KHz +/- 3 dB!


That's the problem. Apparently, what I am looking for is a speaker that
has an off-axis response very similar to its on-axis response. That
seems to explain a soundstage that stays focused from various points in
the room, unless I completely mis-read what Haley was saying.

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Robert Peirce wrote:
In article ,
Audio Empire wrote:

with an on-axis frequency response of 55 to 30KHz +/- 3 dB!


That's the problem. Apparently, what I am looking for is a speaker
that has an off-axis response very similar to its on-axis response.


In practice that's extremely hard to do: the best you can hope for is
something that's reasonably well-behaved. Even that won't guarantee
you a good soundstage everywhere in the room, because stereo isn't
really adequate for that. A separate subwoofer is good advice,
though, because the ideal speaker placement for lower bass may not be
the same place as that for the rest if the spectrum.

Andrew.

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In article ,
John Stone wrote:

How about this:
http://linkwitzlab.com/Pluto/intro.htm

and the upgrade:
http://linkwitzlab.com/Pluto/Pluto-2.1.htm


Can't say. I bookmarked both URLs for later review.



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On Tue, 1 May 2012 08:38:24 -0700, John Stone wrote
(in article ):

On 5/1/12 9:12 AM, in article , "Robert
Peirce" wrote:

In article ,
Audio Empire wrote:

with an on-axis frequency response of 55 to 30KHz +/- 3 dB!


That's the problem. Apparently, what I am looking for is a speaker that
has an off-axis response very similar to its on-axis response. That
seems to explain a soundstage that stays focused from various points in
the room, unless I completely mis-read what Haley was saying.

How about this:
http://linkwitzlab.com/Pluto/intro.htm

and the upgrade:
http://linkwitzlab.com/Pluto/Pluto-2.1.htm



I can't say. I have heard the Orion at the "Burning Amp" DIY audio show and
they were very good, but I don't know how wide their soundstage is , or how
stable their imaging is off-axis.
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On Tue, 1 May 2012 07:12:53 -0700, Robert Peirce wrote
(in article ):

In article ,
Audio Empire wrote:

with an on-axis frequency response of 55 to 30KHz +/- 3 dB!


That's the problem. Apparently, what I am looking for is a speaker that
has an off-axis response very similar to its on-axis response. That
seems to explain a soundstage that stays focused from various points in
the room, unless I completely mis-read what Haley was saying.


Well, since 30 KHz is well beyond the best human hearing, I suspect that
these speakers will still have good response to AT LEAST 15 KHz off-axis.
That's why I mentioned them.

You'll just have to make a short list and go listen....
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"Robert Peirce" wrote in message
...

I am prepared to hear there are exceptions. For example, I have been
told the Steinway Lyngdorf S-series actually does this very well; I had
started to come to the conclusion it wouldn't. There are probably many
other small speakers of which I am unaware that also can serve my
purposes.

The key is very good sound everywhere at the expense of close to perfect
sound at one spot.


If and when I ever have to move to a smaller apartment, I would relish the
chance to experiment with multiple small computer speakers suspended from
the ceiling. I would be able to aim them any which way I want, reflect some
sound from front and side walls, establish a center channel with wide
dispersion, and have multiple surround speakers anywhere I want. The number
of these speakers would make up for any lack of power put out by each one,
and a subwoofer would take care of bass duties. All this while remaining
relatively invisible and needing no Wife Acceptance Factor.

Gary Eickmeier


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"Andrew Haley" wrote in message
...
Robert Peirce wrote:


That's the problem. Apparently, what I am looking for is a speaker
that has an off-axis response very similar to its on-axis response.


In practice that's extremely hard to do: the best you can hope for is
something that's reasonably well-behaved. Even that won't guarantee
you a good soundstage everywhere in the room, because stereo isn't
really adequate for that. A separate subwoofer is good advice,
though, because the ideal speaker placement for lower bass may not be
the same place as that for the rest if the spectrum.


Not hard to do. It's called an omni.

But omni is not necessarily the ideal radiation pattern. What you want is
time/intensity trading in both the direct and early reflected domains. This
plus a certain speaker positioning scheme that is very easy to do and very
beneficial no matter what speakers you have. Just think of your walls as
mirrors, and position the two stereo speakers 1/4 of the room width in from
side walls and out from front wall. If you make a drawing of this, you can
see that the two actual and six reflected (virtual) speakers are positioned
in an even lattice equidistant from each other, for a solid, even, deep,
wide soundstage that can "project" any program material like a 3-dimensional
canvas on which you paint the recorded sound. Notice also that we position
speakers for imaging, not frequency response. For that, we can EQ and use
subwoofers placed in the corners of the room.

Take a look at my earlier response below, the last post in the current
thread. I said it would be fun to take a bunch of small speakers, like
computer desk speakers or home theater sattelites and hang them from the
ceiling and position and aim them to create this magical sound field that
has all of the characteristics of depth, imaging, time/intensity trading so
you can walk all around and get even imaging everywhere. It would be done
with techniques similar to Mark Davis's experiment in creating the
Soundfield One speaker. Add a center channel and surround speakers placed
ideally for your small room, and voila - a sonic Holodeck.

Gary Eickmeier




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Gary Eickmeier wrote:
"Andrew Haley" wrote in message
...
Robert Peirce wrote:


That's the problem. Apparently, what I am looking for is a speaker
that has an off-axis response very similar to its on-axis response.


In practice that's extremely hard to do: the best you can hope for
is something that's reasonably well-behaved. Even that won't
guarantee you a good soundstage everywhere in the room, because
stereo isn't really adequate for that. A separate subwoofer is
good advice, though, because the ideal speaker placement for lower
bass may not be the same place as that for the rest if the
spectrum.


Not hard to do. It's called an omni.

But omni is not necessarily the ideal radiation pattern. What you
want is time/intensity trading in both the direct and early
reflected domains. This plus a certain speaker positioning scheme
that is very easy to do and very beneficial no matter what speakers
you have. Just think of your walls as mirrors, and position the two
stereo speakers 1/4 of the room width in from side walls and out
from front wall. If you make a drawing of this, you can see that the
two actual and six reflected (virtual) speakers are positioned in an
even lattice equidistant from each other, for a solid, even, deep,
wide soundstage that can "project" any program material like a
3-dimensional canvas on which you paint the recorded sound. Notice
also that we position speakers for imaging, not frequency
response. For that, we can EQ and use subwoofers placed in the
corners of the room.


Well, hold on. Placing the speakers at exactly 1/4 of the room width
is going to maximally excite the second mode. Notching that out isn't
going to be so easy, especially if you want to be able to listen in
more than one position. Placing subwoofers in the corners is
efficient, but it also maximally excites *all* of the room modes.

I repeat to the OP: don't believe any simple solutions. I recommend
CARA http://www.cara.de which alows people to do some simulations.

Andrew.



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"Andrew Haley" wrote in message
...

Well, hold on. Placing the speakers at exactly 1/4 of the room width
is going to maximally excite the second mode. Notching that out isn't
going to be so easy, especially if you want to be able to listen in
more than one position. Placing subwoofers in the corners is
efficient, but it also maximally excites *all* of the room modes.

I repeat to the OP: don't believe any simple solutions. I recommend
CARA http://www.cara.de which alows people to do some simulations.

Andrew.


I can only suggest to you that if the room is large enough for realistic
reproduction, and if the radiation pattern is not pure omni, or mostly
direct, but rather has a D/R ratio with negative directivity, then most of
these classical engineering "rules" go out the window. There will be no
serious comb filtering, no room mode problem, no notches or bad peaks. The
reason is that if the direct field is not as strong as most are used to,
then it will not add and subtract in equal proportions to the early
reflected sound. This is the sea change that permits us to position speakers
for imaging, not for frequency response.

The CARA series looks interesting, but I'm not so sure it isn't just another
look at frequency response only, like most of them out there. It is loaded
with pink noise signals and - horrors - sine waves! What the devil use are
sine waves in room acoustics studies?

In my old age curmudgeon phase, I am thinking more and more that the best
test records are well-recorded music and effects that have things happening
all around. Test signals are just a starting point, and you should adjust
levels and EQ by ear more than meters.

Gary Eickmeier


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Gary Eickmeier wrote:
"Andrew Haley" wrote in message
...

Well, hold on. Placing the speakers at exactly 1/4 of the room width
is going to maximally excite the second mode. Notching that out isn't
going to be so easy, especially if you want to be able to listen in
more than one position. Placing subwoofers in the corners is
efficient, but it also maximally excites *all* of the room modes.

I repeat to the OP: don't believe any simple solutions. I recommend
CARA http://www.cara.de which alows people to do some simulations.


I can only suggest to you that if the room is large enough for
realistic reproduction, and if the radiation pattern is not pure
omni, or mostly direct, but rather has a D/R ratio with negative
directivity, then most of these classical engineering "rules" go out
the window. There will be no serious comb filtering, no room mode
problem, no notches or bad peaks.


C'mon Gary, you must know this is nonsense. Below the transition
frequency, speakers are mostly ominidirectional anyway, and you
can't get away from room modes. We cannae change the laws of physics,
captain!

The reason is that if the direct field is not as strong as most are
used to, then it will not add and subtract in equal proportions to
the early reflected sound. This is the sea change that permits us to
position speakers for imaging, not for frequency response.

The CARA series looks interesting, but I'm not so sure it isn't just
another look at frequency response only, like most of them out
there.


Certainly not.

It is loaded with pink noise signals and - horrors - sine waves!


I have no idea what you are talking about.

Andrew.

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On Wed, 9 May 2012 06:07:59 -0700, Gary Eickmeier wrote
(in article ):

"Andrew Haley" wrote in message
...

Well, hold on. Placing the speakers at exactly 1/4 of the room width
is going to maximally excite the second mode. Notching that out isn't
going to be so easy, especially if you want to be able to listen in
more than one position. Placing subwoofers in the corners is
efficient, but it also maximally excites *all* of the room modes.

I repeat to the OP: don't believe any simple solutions. I recommend
CARA http://www.cara.de which alows people to do some simulations.

Andrew.


I can only suggest to you that if the room is large enough for realistic
reproduction, and if the radiation pattern is not pure omni, or mostly
direct, but rather has a D/R ratio with negative directivity, then most of
these classical engineering "rules" go out the window. There will be no
serious comb filtering, no room mode problem, no notches or bad peaks. The
reason is that if the direct field is not as strong as most are used to,
then it will not add and subtract in equal proportions to the early
reflected sound. This is the sea change that permits us to position speakers
for imaging, not for frequency response.

The CARA series looks interesting, but I'm not so sure it isn't just another
look at frequency response only, like most of them out there. It is loaded
with pink noise signals and - horrors - sine waves! What the devil use are
sine waves in room acoustics studies?

In my old age curmudgeon phase, I am thinking more and more that the best
test records are well-recorded music and effects that have things happening
all around. Test signals are just a starting point, and you should adjust
levels and EQ by ear more than meters.

Gary Eickmeier



My current rig, which consists of a pair of Martin-Logan Vantages and a pair
of Aethena self-powered subwoofers in the corners was improved a hundredfold
by using my amp's built-in DSP-based computer EQ system. This works by
following the amp's VF display instructions on where to place an included
microphone for each test.

Not only did it EQ my speakers to be flat in frequency response at my
listening position, but it also, finally, got the crossover right between the
main speakers and the subs. I had been trying to do this by ear for the
better part of a year without much joy. After the EQ program had done its
stuff, I never again felt the need to touch the sub-woofer's controls! I'm
very happy with the sound of my system, frequency-response wise at this time.
I even find that the system images better than it did before it was EQ'd and
I put that down to the smoothing of the frequency response in the room.
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Default Need advice for a small room

On Apr 26, 9:23=A0am, Robert Peirce wrote:
For me, stereo is about the imaging. =A0I can't tell if my room is down
3db at 400hz, and frankly, I don't care as long as it sounds good. I
don't even go in for room treatment of any sort. =A0Every room, including
a concert hall is going to have peaks and dips. =A0I just live with that.

Right now I have a pair of Apogee Divas in a room that is about
15.5'x25'. =A0Maybe I just got lucky, but I can walk just about anywhere
in the room and the image is locked in place. =A0The only place this fail=

s
is if I stand within a foot directly in front of one of the speakers.

I am planning to move and most of the rooms I am looking at tend to be
on the order of 10-12'. =A0Sometimes they are almost square. =A0I was all
hyped up on one product as a possibility for such a room until I found
out it was more about getting correct response from the room then the
kind of imaging I am after.

So, are there any imaging nuts out there who are dealing successfully
with small rooms? =A0What are you doing?


Yikes:

Coming in late, I get to see what has already been discussed to-date.
Cutting to the chase, I would refer you to advice published in the
early 1960s from no less than Acoustic Reseach on speaker placement.
Given that they specialized in acoustic-suspension 'bookshelf'
speakers of conventional/conservative (today) design, this will not
apply in detail to your speakers, but it will do so in general.

Take the longest wall in your room. Place one speaker (A) about two
woofer-diameters in from one corner. Place the other (B) about midway
between the first speaker and the other wall. Experiment with the
placement of speaker B until you have the what you perceive as the
best placement. Start with both speakers as close to the wall as
possible, moving only speaker B until you are happy. Then A out from
the wall (or not) and so forth. In/out from the wall affects bass
primarily. Distance from the walls and each other affects soundstage
primarily. Asymmetrical placement reduces/eliminates standing waves
and cancellation waves as well as multiple sorts of room effects.

This will give you the widest "sweet spot" available - closest to what
you (apparently) perceive in your present location.

Repeat the process on the shorter wall.

AR suggested at the time that if there was a listening audience and if
the listening room was used for other purposes than music, the long-
wall placement would quite regularly 'win' as it gave the greatest
audience spread. If for a single listener in a dedicated room, the
short-wall would win as the sweet spot could be made quite small. And
the natural progression to that concept is headphones.

OPINION (typical rant removed): I find the concept of a tiny sweet
spot as antithetical to the listening experience and about the
furthest thing from duplicating a live setting as is possible (except
for headphones). If I *must* keep my ears within a 12"/31cm cube in
order to realize the best possible performance from my speakers - that
is simply nuts.

Peter Wieck
Melrose Park, PA

AR3a
Maggie MG-III
Revox Piccolo
ARM5
AR14
AR Athena
Dynaco A25

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Peter Wieck Peter Wieck is offline
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On May 10, 11:55=A0am, ScottW wrote:
On May 10, 6:10=A0am, Peter Wieck wrote:

On Apr 26, 9:23=A0am, Robert Peirce wrote:


=A0 I felt the same way...until my Quads created an oh so small, but oh
so sweet...spot.

ScottW


I would never dispute the sweetness of the spot - but I would dispute
the adequacies of the speakers and/or the forced placement in the room
if that spot were the only truly sweet option.

Point being that headphones will accomplish that ideal at a fraction
of the cost, time or trouble.

Peter Wieck
Melrose Park, PA



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On Thu, 10 May 2012 06:10:57 -0700, Peter Wieck wrote
(in article ):

OPINION (typical rant removed): I find the concept of a tiny sweet
spot as antithetical to the listening experience and about the
furthest thing from duplicating a live setting as is possible (except
for headphones). If I *must* keep my ears within a 12"/31cm cube in
order to realize the best possible performance from my speakers - that
is simply nuts.

Peter Wieck
Melrose Park, PA

AR3a
Maggie MG-III
Revox Piccolo
ARM5
AR14
AR Athena
Dynaco A25


While I agree with you in theory, the reality is that the "sweet spot"
concept is part of the baggage that stereo recording methodology carries with
it. I've mentioned this before, but it doesn't hurt to reiterate:

When you are at a live, unamplified concert, and you move around with respect
the stage (or other locus of performance) your ears go with you and your
perspective changes with location. When listening to a recording, and you
move around the room, your surrogate ears, the microphones, and ultimately,
(in the case of multi-miked, multi-channel recordings) the final mix has one
set perspective because the "mikes" DON'T move. That being the case, there
is only ONE set place where the perspective is correct, IOW, there is only
one place in front of the speakers (right to left) where the listener is on
the same axis as the surrogate ears. Naturally, this is the place where the
imaging and soundstage snap into sharp focus. If you aren't in that spot, you
still hear a sound-field, but the focus will be gone. An analogy would be a
3-D visual image. As you move the right-eye image and the left-eye image
closer together and further apart, there is only one relative position where
these two images coalesce in your mind as a single 3-D image (assuming, of
course, you are wearing the glasses) with depth as well as height and width.
That's because your surrogate eyes are a pair of lenses on a camera that are
a set distance apart. That means that when viewing those images they must
give the illusion of being the same distance apart to your brain, or you
won't see the stereo effect - with or without the glasses.
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On Thu, 10 May 2012 11:53:52 -0700, Peter Wieck wrote
(in article ):

On May 10, 11:55=A0am, ScottW wrote:
On May 10, 6:10=A0am, Peter Wieck wrote:

On Apr 26, 9:23=A0am, Robert Peirce wrote:


=A0 I felt the same way...until my Quads created an oh so small, but oh
so sweet...spot.

ScottW


I would never dispute the sweetness of the spot - but I would dispute
the adequacies of the speakers and/or the forced placement in the room
if that spot were the only truly sweet option.

Point being that headphones will accomplish that ideal at a fraction
of the cost, time or trouble.

Peter Wieck
Melrose Park, PA


Not really. Unless we are talking about binaural recordings, 'phones don't
really do stereo very well. The images are usually inside one's head (I mean
spatially, not as in "sound is made in the brain rather than the ears) when a
stereo recording is played. But good binaural can be extremely realistic
sounding (until one moves one's head and the image moves it).
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Gary Eickmeier Gary Eickmeier is offline
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Default Need advice for a small room

"Audio Empire" wrote in message
...

While I agree with you in theory, the reality is that the "sweet spot"
concept is part of the baggage that stereo recording methodology carries
with
it. I've mentioned this before, but it doesn't hurt to reiterate:

When you are at a live, unamplified concert, and you move around with
respect
the stage (or other locus of performance) your ears go with you and your
perspective changes with location. When listening to a recording, and you
move around the room, your surrogate ears, the microphones, and
ultimately,
(in the case of multi-miked, multi-channel recordings) the final mix has
one
set perspective because the "mikes" DON'T move. That being the case,
there
is only ONE set place where the perspective is correct, IOW, there is only
one place in front of the speakers (right to left) where the listener is
on
the same axis as the surrogate ears. Naturally, this is the place where
the
imaging and soundstage snap into sharp focus. If you aren't in that spot,
you
still hear a sound-field, but the focus will be gone. An analogy would be
a
3-D visual image. As you move the right-eye image and the left-eye image
closer together and further apart, there is only one relative position
where
these two images coalesce in your mind as a single 3-D image (assuming, of
course, you are wearing the glasses) with depth as well as height and
width.
That's because your surrogate eyes are a pair of lenses on a camera that
are
a set distance apart. That means that when viewing those images they must
give the illusion of being the same distance apart to your brain, or you
won't see the stereo effect - with or without the glasses.


No. Not analogous.

There need not be a single "sweet spot" nor a single perspective that was
viewed by some single stereo microphone.

The example in my Mars paper - which I think I sent you - was of an
imaginary recording made with one microphone per instrument, then played
back on speakers that have similar radiation patterns to the instrument they
are reproducing, and are placed in positions that are geometrically similar
to the original. Such an ideal system creates a sound field that is
spatially a duplicate of the original. You can move around in it just like
live. The realism of it depends on the size of the room being similar to the
original, or what the original would be good in. And most notably, neither
the recording nor the reproduction have anything to do with the number of
ears on your head or the spacing between them or any single position of any
microphone during the recording. Stereo is not a head-related system like
binaural, nothing to do with the human hearing mechanism, but rather the
creation of sound fields in rooms.

It is confusing when we begin to simplify the system down to fewer channels,
especially if it gets all the way down to two channels, because then we
begin to think that the two speakers are reproducing EAR SIGNALS, which they
are not. The only aspect of playback that relates to the human hearing
mechanism is the summing localization that is employed to create the phantom
imaging between speakers. Discrete surround sound with the center channel
gets us some of the way away from that confusion, but the nature of the
system remains the same, and the confusion will always be with us. But even
with a simplified-down system there needn't be a single sweet spot or single
perspective on the instruments, if you employ a proper radiation pattern,
speaker positioning, and a good room.

Gary Eickmeier


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On Fri, 11 May 2012 06:02:09 -0700, Gary Eickmeier wrote
(in article ):

"Audio Empire" wrote in message
...

While I agree with you in theory, the reality is that the "sweet
spot" concept is part of the baggage that stereo recording
methodology carries with it. I've mentioned this before, but it
doesn't hurt to reiterate:

When you are at a live, unamplified concert, and you move around
with respect the stage (or other locus of performance) your ears
go with you and your perspective changes with location. When
listening to a recording, and you move around the room, your
surrogate ears, the microphones, and ultimately, (in the case of
multi-miked, multi-channel recordings) the final mix has one set
perspective because the "mikes" DON'T move. That being the case,
there is only ONE set place where the perspective is correct, IOW,
there is only one place in front of the speakers (right to left)
where the listener is on the same axis as the surrogate ears.
Naturally, this is the place where the imaging and soundstage snap
into sharp focus. If you aren't in that spot, you still hear a
sound-field, but the focus will be gone. An analogy would be a 3-D
visual image. As you move the right-eye image and the left-eye
image closer together and further apart, there is only one relative
position where these two images coalesce in your mind as a single
3-D image (assuming, of course, you are wearing the glasses) with
depth as well as height and width. That's because your surrogate
eyes are a pair of lenses on a camera that are a set distance
apart. That means that when viewing those images they must give the
illusion of being the same distance apart to your brain, or you
won't see the stereo effect - with or without the glasses.


No. Not analogous.

There need not be a single "sweet spot" nor a single perspective
that was viewed by some single stereo microphone.

The example in my Mars paper - which I think I sent you - was of an
imaginary recording made with one microphone per instrument, then
played back on speakers that have similar radiation patterns to the
instrument they are reproducing, and are placed in positions that
are geometrically similar to the original. Such an ideal system
creates a sound field that is spatially a duplicate of the
original. You can move around in it just like live. The realism of
it depends on the size of the room being similar to the original,
or what the original would be good in. And most notably, neither
the recording nor the reproduction have anything to do with the
number of ears on your head or the spacing between them or any
single position of any microphone during the recording. Stereo is
not a head-related system like binaural, nothing to do with the
human hearing mechanism, but rather the creation of sound fields in
rooms.

It is confusing when we begin to simplify the system down to fewer
channels, especially if it gets all the way down to two channels,
because then we begin to think that the two speakers are
reproducing EAR SIGNALS, which they are not. The only aspect of
playback that relates to the human hearing mechanism is the summing
localization that is employed to create the phantom imaging between
speakers. Discrete surround sound with the center channel gets us
some of the way away from that confusion, but the nature of the
system remains the same, and the confusion will always be with us.
But even with a simplified-down system there needn't be a single
sweet spot or single perspective on the instruments, if you employ
a proper radiation pattern, speaker positioning, and a good room.


While much of what you say is true, with two channels, there is only a
very narrow range of listening positions where the aural images are in
focus. This has to be. Microphones aren't ears and they don't even ACT
like ears and in fact we don't want them to act like ears, because if
they did, we would have binaural recordings, not stereo recordings.
But they do build-up a snapshot of the performance from a fixed
perspective. It doesn't matter whether this perspective is the result
of some co-incident microphone technique such as M-S or ORTF, or
whether it's the result of widely-spaced omnis, or whether it's a
studio-mixed sound-field made up from the outputs of dozens of
microphones recorded to dozens of separate channels all mixed down to
two. The result, on the listener's end is the same. A fixed
perspective that does not move when the listener moves.

You are right again when you say that the only way around this is to
have a microphone and channel per instrument and a speaker on the
listening end per instrument all arranged exactly where the original
instrument was arranged during the recording process. This would give
the playback a similar image specificity to a real performance. Bell
Labs noted this in their 1933 stereophonic experiments. They started
with one channel per instrument (not recorded, of course, merely
piped-in by hard-wire from another, remote location) and kept reducing
the number of channels (on both ends) until but two remained. They
noted that it was entirely practical to convey the stereophonic
effect with merely two channels, but they also added the caveat that
with two channels, the optimum stereo effect was achieved only at the
point in front of the speakers where the sound-fields from the two
channels intersect.
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On Fri, 11 May 2012 16:11:51 -0700, ScottW wrote
(in article ):

On May 11, 6:02am, "Gary Eickmeier" wrote:
"Audio Empire" wrote in message
...

Snip

You can move around in it just like live. The realism of it depends
on the size of the room being similar to the original, or what the
original would be good in. And most notably, neither the recording
nor the reproduction have anything to do with the number of ears on
your head or the spacing between them or any single position of any
microphone during the recording.


All very nice theory, but reality is most of us are dealing with
stereo recordings.
One reason I think the Quads image so well is there lack of wide
dispersion and therefore reduced reflection interference. Best
imaging systems are in either highly damped (non-reflective rooms),
near field setups, or controlled dispersion IMO.
Frequency response doesn't have a lot of correlation with imaging to
me.

ScottW


I can't speak for the Quads as I've never lived with a pair, but I can tell
you that the reason why the Martin-Logans image so well is because of their
curved screens, I once had a pair of Innersound flat panel electrostatics in
my listening room for about three months and they drove me mad. The flat
panel ES element required that the LISTENER (notice the lack of a plural,
here) do an elaborate set-up involving holding a small flashlight in one's
mouth and pointing ones' head dead-ahead. Then one moved the panels until one
could see the flashlight reflection, equally, in the center of both panels.
Then one had to sit as if one's head was in a vise or the imaging would
collapse and the highs would go away. If you sat perfectly still, OTOH, they
did sound marvelous.

With the M-Ls, the curvature of the screen, meant that starting in the upper
midrange, the section of the curve facing the listener acts as a line source.
So wherever you sit, as long as you are on axis with both curved surfaces,
you get a decent image. Indeed, the sweet spot is very wide with these
speakers and can comfortably accommodate several listeners at once.


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Audio Empire wrote:

While much of what you say is true, with two channels, there is only a
very narrow range of listening positions where the aural images are in
focus. This has to be. Microphones aren't ears and they don't even ACT
like ears and in fact we don't want them to act like ears, because if
they did, we would have binaural recordings, not stereo recordings.
But they do build-up a snapshot of the performance from a fixed
perspective. It doesn't matter whether this perspective is the result
of some co-incident microphone technique such as M-S or ORTF, or
whether it's the result of widely-spaced omnis, or whether it's a
studio-mixed sound-field made up from the outputs of dozens of
microphones recorded to dozens of separate channels all mixed down to
two. The result, on the listener's end is the same. A fixed
perspective that does not move when the listener moves.


Well, I hope you can see that this "fixed perspective" is a property of the
reproduction and not a basic property of the system. In fact, if you have a
multi-miked recording (which is NOT in incorrect technique in any sense)
then there IS no "perspective" from which the recording was made. If you had
the multitrack master, if it was recorded that way, then you could actually
pipe each mike thru a channel of its own out to a speaker positioned where
it was and you would have my example.

You are right again when you say that the only way around this is to
have a microphone and channel per instrument and a speaker on the
listening end per instrument all arranged exactly where the original
instrument was arranged during the recording process. This would give
the playback a similar image specificity to a real performance. Bell
Labs noted this in their 1933 stereophonic experiments. They started
with one channel per instrument (not recorded, of course, merely
piped-in by hard-wire from another, remote location) and kept reducing
the number of channels (on both ends) until but two remained. They
noted that it was entirely practical to convey the stereophonic
effect with merely two channels, but they also added the caveat that
with two channels, the optimum stereo effect was achieved only at the
point in front of the speakers where the sound-fields from the two
channels intersect.


Yes, again, playback only situation, not systemic. And I thought they ended
up with a three channel system.

The movie people are always one step ahead of the pure audio people. You can
see that at least with DD 5.1 surround sound, you can be anywhere in the
audience and perceive the center channel dialog as coming from the center of
the screen.

Stereo theory is constantly confused with binaural theory due to the
widespread use of the two channel system. We've got to shake that off and
start from scratch. I really like your example of the Innersound
electrostatics driving you mad. I had the same reaction to the Acoustats.
The classical theorists would think this an ideal situation, if the two
channels were "ear signals" meant to be piped to your ears. All that would
be missing would be crosstalk cancellation to get all the way to binaural
and total confusion.

I hope that your listening experience with the curved panel electrostatics
also includes a more natural, realistic sound field generated in your room.
Some listeners (Siegfried Linkwitz among others) realize that the reflected
sound can be a part of the realistic construction of the stereo image, and
in fact should be the same frequency response as the direct sound, not an
accidental byproduct of whatever sound comes off the back of a box speaker.

The whole theory of stereo is usually taken wrong because of these multiple
errors and misconceptions, and there doesn't seem to be a path out of it,
because of a lot of folklore and a lack of a single theory on exactly what
it is that we are doing with auditory perspective systems. Two channel
stereo is the main culprit, and multichannel is a partial solution, thanks
to the film people.

But can't we short-circuit all the cut and try fumbling and examine the
macro situation and state it once and for all?

Gary Eickmeier





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On Sat, 12 May 2012 18:23:01 -0700, Gary Eickmeier wrote
(in article ):

Audio Empire wrote:

While much of what you say is true, with two channels, there is only a
very narrow range of listening positions where the aural images are in
focus. This has to be. Microphones aren't ears and they don't even ACT
like ears and in fact we don't want them to act like ears, because if
they did, we would have binaural recordings, not stereo recordings.
But they do build-up a snapshot of the performance from a fixed
perspective. It doesn't matter whether this perspective is the result
of some co-incident microphone technique such as M-S or ORTF, or
whether it's the result of widely-spaced omnis, or whether it's a
studio-mixed sound-field made up from the outputs of dozens of
microphones recorded to dozens of separate channels all mixed down to
two. The result, on the listener's end is the same. A fixed
perspective that does not move when the listener moves.


Well, I hope you can see that this "fixed perspective" is a property of the
reproduction and not a basic property of the system. In fact, if you have a
multi-miked recording (which is NOT in incorrect technique in any sense)


I suppose that depends upon what you are trying to record. If you are
recording a rock-n-roll band, it's fine (since most rock-n-roll
performances can't exist outside of the studio, anyway). It is even
"the correct way" if you are recording a jazz group using the
"traditional" 3-channel mono technique (where the ensemble in broken
up into three groups and the groups are pan-potted right, left, and
center). However, it would be a misnomer to call any multi-miked,
muti-track recording "stereo". It simply isn't ; it is merely
multi-channel monaural sound. And if you think that it is not an
incorrect technique to multi-mike a symphony orchestra, then we are
going to have to agree to disagree, because in my estimation, that
procedure is EVERY KIND OF WRONG!

then there IS no "perspective" from which the recording was made.


I still disagree. The "perspective" is the one chosen by the mix
engineer when he assigns instruments or groups of instruments to their
left-to-right positions by pan-potting them into place. For instance
if he is mixing a jazz quartet where the dominant instrumentalist is a
sax, and he pan pots it equally between left and right, then it will
appear in the phantom center channel. He might then pan the drum kit
to the left, the bass to the right, along with the piano. That's the
"perspective" that the mix engineer (and, ostensibly, the producer),
wants.

If you had
the multitrack master, if it was recorded that way, then you could actually
pipe each mike thru a channel of its own out to a speaker positioned where
it was and you would have my example.


Certainly you would. And as long as the speaker occupied the same
relative space on the playback side that the original instrument
occupied in the record space, then you would have a fair
representation of the original DIRECT sound field (but none of the
venue's ambience).

You are right again when you say that the only way around this is to
have a microphone and channel per instrument and a speaker on the
listening end per instrument all arranged exactly where the original
instrument was arranged during the recording process. This would give
the playback a similar image specificity to a real performance. Bell
Labs noted this in their 1933 stereophonic experiments. They started
with one channel per instrument (not recorded, of course, merely
piped-in by hard-wire from another, remote location) and kept reducing
the number of channels (on both ends) until but two remained. They
noted that it was entirely practical to convey the stereophonic
effect with merely two channels, but they also added the caveat that
with two channels, the optimum stereo effect was achieved only at the
point in front of the speakers where the sound-fields from the two
channels intersect.


Yes, again, playback only situation, not systemic. And I thought they ended
up with a three channel system.


Read and Welch ('From Tinfoil to Stereo' C. 1967 Howard Sams & Co.,
Inc.) say that the Bell Labs stereo experiements settled on two
channels.

The movie people are always one step ahead of the pure audio people. You can
see that at least with DD 5.1 surround sound, you can be anywhere in the
audience and perceive the center channel dialog as coming from the center of
the screen.


They use three discrete channels in front , so I suspect they would
get a strong dialog channel in the center.

Stereo theory is constantly confused with binaural theory due to the
widespread use of the two channel system. We've got to shake that off and
start from scratch. I really like your example of the Innersound
electrostatics driving you mad. I had the same reaction to the Acoustats.
The classical theorists would think this an ideal situation,


I can't imagine why. I would think that the ideal would be a broad,
stable stereo image with wide dispersion that would give listeners a
decent stereo image no matter where in the sound field they sat.

if the two channels were "ear signals" meant to be piped to your
ears. All that would be missing would be crosstalk cancellation to
get all the way to binaural and total confusion.


Binaural only works with headphones. Even then it's not perfect. The
binaural miking setup cannot differentiate sounds coming from the dead
front from sounds coming from the dead rear of the "head".

I hope that your listening experience with the curved panel electrostatics
also includes a more natural, realistic sound field generated in your room.
Some listeners (Siegfried Linkwitz among others) realize that the reflected
sound can be a part of the realistic construction of the stereo image, and
in fact should be the same frequency response as the direct sound, not an
accidental byproduct of whatever sound comes off the back of a box speaker.


Well, as with most domestic situations, it is what it is.

The whole theory of stereo is usually taken wrong because of these multiple
errors and misconceptions, and there doesn't seem to be a path out of it,
because of a lot of folklore and a lack of a single theory on exactly what
it is that we are doing with auditory perspective systems. Two channel
stereo is the main culprit, and multichannel is a partial solution, thanks
to the film people.

But can't we short-circuit all the cut and try fumbling and examine the
macro situation and state it once and for all?


I don't think so. The live sound field is incredibly complex. Each
instrument's sound takes it's own path(s) from the instrument to the
ear. It is also mixed in the air with the other instruments
accompanying it and it is followed by primary and secondary
reflections off of every surface, hard or soft, in the room. How can
one ever decide how many channels is enough to convey all the right
cues for every conceivable mix of instruments in every conceivable
type of venue? I think that just getting two-channel stereo right is
difficult enough (witnessed by the fact that it is so seldom done
correctly) and that's a worthy goal, in and of itself.
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Gary Eickmeier Gary Eickmeier is offline
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Default Need advice for a small room

"Audio Empire" wrote in message
...

I suppose that depends upon what you are trying to record. If you are
recording a rock-n-roll band, it's fine (since most rock-n-roll
performances can't exist outside of the studio, anyway). It is even
"the correct way" if you are recording a jazz group using the
"traditional" 3-channel mono technique (where the ensemble in broken
up into three groups and the groups are pan-potted right, left, and
center). However, it would be a misnomer to call any multi-miked,
muti-track recording "stereo". It simply isn't ; it is merely
multi-channel monaural sound. And if you think that it is not an
incorrect technique to multi-mike a symphony orchestra, then we are
going to have to agree to disagree, because in my estimation, that
procedure is EVERY KIND OF WRONG!


I can only offer you the Telarc and Mercury three spaced omni technique
which won popular acclaim for a long period of time. So much so that Stan
Lip****z found it important to rail against it in his famous article "Stereo
Microphone Techniques: Are the Purists Wrong?".

http://www.aes.org/e-lib/browse.cfm?elib=11494

I claim in my papers that the spaced omni technique is the more correct, for
reasons pointed out in my stereo theory (Image Model Theory, IMT)

http://www.aes.org/e-lib/browse.cfm?elib=5825

Basically, the three omnis are sampling the sound field at 3 locations in
the concert hall, rather than at one central location as with Stanley's
coincident technique and your ideas. There is no single "perspective" from
which you are supposed to witness the sound; if done properly, you should be
able to move around in your playback room and perceive the sound from
various perspectives, just as live. Note also that the three microphones are
picking up not just direct sound, but the room ambience from the left and
right sides and from the center. To play these recordings properly, you do
NOT want that ambience to come from the direct field of your three front
speakers, but from a wide set of incident angles, modeled after the real
thing, and supplemented by surround speakers on delay. Hence, the importance
of the radiation pattern of the front speakers and a correct mix of direct
and reflected emanating from the speakers, with equi-omni frequency response
and room positioning that also models the playback situation after the live
event..

I still disagree. The "perspective" is the one chosen by the mix
engineer when he assigns instruments or groups of instruments to their
left-to-right positions by pan-potting them into place. For instance
if he is mixing a jazz quartet where the dominant instrumentalist is a
sax, and he pan pots it equally between left and right, then it will
appear in the phantom center channel. He might then pan the drum kit
to the left, the bass to the right, along with the piano. That's the
"perspective" that the mix engineer (and, ostensibly, the producer),
wants.


That is the layout of the instruments that the engineer wants, but you may
be able to move around in your listening room and perceive them from various
perspectives. Doesn't work like a visual 3D image or a binaural audio
recording. My IMT sees the reproduction as a model of the real thing, that
you can move around in, rather than a sort of "window" or portal to another
acoustic space, through which you must sit and listen from a single
perspective.

If you had
the multitrack master, if it was recorded that way, then you could
actually
pipe each mike thru a channel of its own out to a speaker positioned
where
it was and you would have my example.


Certainly you would. And as long as the speaker occupied the same
relative space on the playback side that the original instrument
occupied in the record space, then you would have a fair
representation of the original DIRECT sound field (but none of the
venue's ambience).


Why? Where did it go?

I don't think so. The live sound field is incredibly complex. Each
instrument's sound takes it's own path(s) from the instrument to the
ear. It is also mixed in the air with the other instruments
accompanying it and it is followed by primary and secondary
reflections off of every surface, hard or soft, in the room. How can
one ever decide how many channels is enough to convey all the right
cues for every conceivable mix of instruments in every conceivable
type of venue? I think that just getting two-channel stereo right is
difficult enough (witnessed by the fact that it is so seldom done
correctly) and that's a worthy goal, in and of itself.


You are unnecessarily confusing yourself. All of that "complexity" is being
recorded by the microphones and can be reproduced fairly well - well enough
for musical enjoyment - in a loudspeaker playback situation. We cannot get
all the way there because of the nature of the system (the "central
recording problem" of having to run the sound through two different acoustic
spaces), so we must understand what is happening and the limitations of the
system and what we can hear.

All of this does pertain to the OP's initial question, so I don't feel like
we are hijacking the thread too bad, but I would like to take it to a new
thread with a new tack from my usual line, if you would like to follow me
there.

What can we hear?

Gary Eickmeier





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