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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