Bromo wrote in message news:w9fyb.365343$Fm2.365365@attbi_s04...
Agreed - however, as we all do not sit in anechoic chambers whilst
listening, our room acoustics will predominate in all cases, be it 2, 6 or
10 speakers!

Room acoustics will still be very important, but the important thing
about multichannel is that it can provide the right perceptual cue at
the right level at the right time from the right direction, whereas
two-channel has to rely on a treated room to simulate such things, and
then such simulations cannot be accurate (though they may still sound
nice).

Given real world experiences, and real setups (I have a 5.1 system that
plays great stereo -- Thiel) I have found your actual room acoustics will
tend to add or subtract far more from your "being there" experience than the
number of speakers. This was a rather expensive conclusion to come to as I
could have saved a lot of money by just getting the stereo system.

I agree with you actually, but for a different reason. I think the
multichannel world's gotten too caught up with the number of channels
as a measure of quality, because it says nothing about something else
equally or even more important --- what goes into those channels!

A better model is to expand on what Ambisonics has done (I'm not
advocating Ambi, by the way), and use an acoustic reconstruction
theory which is then rendered on playback by some number of speakers.
Simplistically, the theory would specify the kind of acoustical
phenomena (hopefully derived from a study of human perception so we
only deal with the ones that are going to matter to the hearing
system) it's going to encode. The playback system will know how many
speakers it has, and where they're placed, and render the captured
acoustic information as accurately and pleasingly as possible (again
this has to be modeled perceptually instead of something simple and
convenient like least squares). The capture system (the mics and
their placement) can also be parametrically defined by this theory.
The big advantage of such a system is scalability, and efficiency of
transport --- we don't need to guarantee 12 channels or whatever of
bandwidth, just the same constant bandwidth for the a particular set
of acoustic information. Of course, the theory engine itself has to
be scalable and separate, so it can be replaced or expanded as our
knowledge and experience grows. IMO, this is the one big problem with
Ambisonics --- it captures information at only one point in space,
which is perceptually unrealistic, but many of the other things it
does are very elegant and even beautiful.

I have not experienced the "shoutiness" you are complaining about - perhaps
room acoustics are to blame here - or perhaps speakers/amps being overdriven
- or perhaps you ears are being overloaded - I noticed that during rock
concerts in my younger days.

I think it may the room acoustics, or turning up the speakers to hear
something that's being masked by the room, so the rest of the spectrum
is very loud. I've recently switched to a hybrid dipole speaker
(Linkwitz Orion) which reduces room interaction significantly, and
things have improved greatly, including the shoutiness.

My setup can play very comfortably in the 85dB-90dB range - though I rarely
go above 75-80dB since I feel most comfortable at these softer levels and
can easily be drawn in to the music at those levels.

I actually listen softer, like 65 to 72 dB SPL. This is just a guess:
my volume knob is at -20 to -13 dB relative to digital full-scale,
and the system's calibrated to do 85 dB SPL C-weighted pink noise at
+0 dB on the knob. So depending on program material (eg. highly
level-compressed stuff), the actual SPL may vary a bit.

At the end of the day - if you are really happy with good 5.1 presentation
of music - then that is all that really matters - after all, this is a
passion and entertainment for most of us, nothing that would make the
difference between life-or-death.

And despite our best efforts so far - the ultimate "being there" experience
is -- being there!

Yes, I agree. I could not say it better.

--Andre