[Peter Wieck]

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