Mogens V. wrote:
William Sommerwerck wrote:
IMHO the best way to get a good classical recording is to use a good
hall
to make the recording and put the microphones on the right place.
Yes, but how do you do that with existing, commercial recordings,
which is
what the OP was asking about?
Well, a couple points. If it's popular/pop music, one may choose to not
even bother 
If it's classical, one may choose another recording.
Nevertheles, even though I prefer recordings the way they were made (and
hopefully intended) by the rec engineer, I never opted for a surround
system, to much criticism from friends (a gots-to-have these days).
With two-channel audio the engineer, no matter how good he
is, has to make a compromise. With live music, most of the
reverb one hears comes from places other than the soundstage
area. However, with two-channel recordings, all of that hall
reverb comes from up front. The home listening room adds
reverb, of course, but it is much different from what the
hall would deliver. The engineer is stuck with that
situation when making two-channel recordings.
Using a home-based reverb synthesizer (which may take the
mono attribute of a recording and reverberate it to surround
speakers) or a reverb extractor (which may take the L minus
R part of the recorded source material and send it directly
to the surround speakers, usually after applying some delay
and maybe additional reverb) helps to overcome this problem.
This is the case if either technology is well engineered and
the levels are not goosed too much and the room is decent
and the speakers are located properly. The result will get
some ersatz reverb out into the room and help to make a bad
situation a bit better. No system can properly duplicate a
real-world hall, but extracted or synthesize reverb in
combination with two or three channels up front is a much
better approach than basic two-channel stereo.
I'd prefer a good stereo with full range fronts and tonewise matching
rear speakers for pseudo-quadro/surround for films _and_ for a more
spacious experience for at least some music.
I have absolutely no interest in center speakers and subwoofers.
Well, if one's main speakers are solid bass producers a
subwoofer may not be required, particularly with lighter
weight musical source materials. However, a really good,
really well integrated subwoofer can do several things
better than full-range speakers operating alone.
First, it takes pressure off of the satellite amps. They no
longer have to deal with low bass.
Second, it takes pressure off of the satellite woofer
sections. They no longer have to deal with low bass, which
can be very important if those woofers in the satellites are
not particularly potent.
Third, set up right (close to two or more room boundaries) a
subwoofer helps to eliminate boundary-related suckout
artifacts that one gets with typically set-up satellite
speakers that are positioned well out into the open. With
the proper crossover frequency, the sub operates below its
suckout cancellation point and the satellites operate above
theirs.
Fourth, good subs will get the bottom octave better than
most full-range speakers. Yes, most music does not go down
to 20 Hz, but in many cases hall ambiance does go that low,
or even lower, and so a good subwoofer will do a better job
of simulating the subjective "space" of a good hall better
than most full-range speakers.
As for the center channel, look at it this way. During a
live performance a centered soloist will be generating two
arrival clues: one for each ear. However, with two-channel
reproduction and a "phantom" center a centered soloist
generates four arrival clues: one from each speaker for each
ear. This is abnormal, both in terms of inter-system
frequency-response cancellations and also in terms of focus,
particularly when listening from anywhere but the sweet
spot, and has only been lauded by traditionalists because
they are not aware of just what a centered soloist sounds
like in a real-world hall. Going to a center channel (even
one that involves "deriving" a steered center feed from the
L+R part of a stereo source) gives the listener the more
realistic two arrival clues.
Yes, you still get cancellations and other artifacts between
the center channel speaker and the left and right mains, but
having an additional channel reduces their impact compared
to what they sound like with only two channels.
Uhh ohh, I'm most surely going to be lectured now :-D
But not lectured in a nasty way, at least by me.
Howard Ferstler