On 1 Jul 2003 14:59:52 GMT, "chelvam" wrote:

I may be wrong but I think a good set up can create sound beyond the
standard 60 deg. Stereo system can produce sound at almost 80 degrees and
beyond and in some tracks I do hear sound travel from rear to front and vice
versa.

Yes but that sound is spurious, not real, although it may be pleasing.
It is the sound of the listening room.

Once I attended a demo using Qsound recording (Roger Water -Amused to death)
to produce the surround effect. The guy toed out the speakers and the room
was fully padded. I could hear the sound at 90 deg and the racing car was
going in circles. Unfortunately, due to the extensive padding everything
sounded "dead". Some liked the effect. No surround here just two speakers.

Well, one can fiddle with phasing and try to simulate the HRTF but it
is still not the real ambience of the recording site.

How wide should a stereo system sound? I believe, IMHO, as wide as a stage
set up. The only thing I dislike about the stereo recording is the crowd's
applause is always coming from the front instead from the rear or around us.
In orchestra, the sound do not come from the rear but front. the only thing
that would come from the rear is the huge pipe organ.

What I dislike is the decay of ambience/reverb TOWARDS the front!

The next question, what additional benefit that we get from extra rear
speakers? Well some say ambience. what is ambience?
Ambience retrieval-the ability to capture the distinctive sound of a given
space.... (extracted from the absolute sound mag). So the sound of
performance in Carnegie Hall is more captivating due to the ambience
retrieval of the hall. So a recording of Harry Belafonte in Carnegie Hall
consist of the actual instrument sound and together with the ambience of the
Hall itself. Now how do we expect it to sound in our room?. The recorded
sound plus the room's signature. The ideal room would be one with limited
room interacting but without sounding dead in that case you get the right
ambience in your own room.

Sure and the effective use of MCH will supercede much of your room
sound if done right.

Now the next question, should the ambience have any direction? Polk audio
recommends the rear speakers to be connected out of phase. We all understand
that in out of phase mode the sound appears to come from everywhere. That's
what ambience do, they are secondary reflection form the original sound. The
correct combination of both is what matters most.

There are many ways to make phony ambience pleasing, beginning with
the Hafler circuit.

In a way, the surround/multi channel simplifies things for us.

Many things are simplified but not all.

Kal