From: chrisc@gold.gvg.tek.com (Chris Christensen)
Newsgroups: rec.audio.pro
Subject: Re: QSound?
Date: 12 Sep 92 17:50:36 GMT
Organization: Grass Valley Group, Grass Valley, CA

In article <TONYB.92Sep10133901@titania.juliet.ll.mit.edu> tonyb@juliet.ll.mit.edu ( Tony Berke ) writes:
>In article <5172@gold.gvg.tek.com> chrisc@gold.gvg.tek.com (Chris Christensen) writes:

>   [Chris' text edited]
>   When you switch to mono the only thing that should collapse is
>   the stereo image.

>   Monitoring a recording in mono will graphically point out out serious phase
>   errors.  I have actually mixed in mono once the stereo image was determined
>   (amplitude stereo).  I have found that if it sounds good in mono it will
>   still sound good in stereo........

>   A good stereo recording should *still* sound good in mono!

>This would seem to reflect an inherent bias towards intensity stereo.
>Or more likely, my incomplete understanding of the topic ;-)  Won't
>any near-coincident stereo technique suffer from comb filtering in
>the upper octave(s) for off-axis sources, or do the directional
>characteristics of the mics keep that from happening when things are
>going correctly ?

I use microphones that have textbook perfect off axis response so the
problems associated with non-linear (with frequency) comb filtering is
minimised.

I have been "warned" about the comb filtering effects of a
near-coincident stereo technique but I haven't suffered from it. I
have done over two hundred recordings in this manner and achieved
rewarding results with no surprises!

The way that I set up my stereo array (most of the time) has the left
and right mic pointed away from each other and they pretty much keep
out of each others way.  Yes there is a comb filtering effect at the
spacing of the mics to some extent but since they are not totally in
each others space this affect is at a level way below the main record
level.

I do throw caution to the wind when I set up my Triad Stereo Mic
Array.  This is where I put the center mic in between the Left and
Right mics. Oh and the center mic isusually mixed in a few dB lower
than the Left and Right mics.  I really hate the "hole in the middle"
sound of some recording techniques!

The capsule to capsule distance ends up being about 4" inbetween the L
and R  to the center capsules.  Also for those who are interested the capsules
are about 1/2" in dia.

I do not even try to encode any phase information other than what occurs
between the capsules and I find the intensity stereo very rewarding
indeed!  This Triad  array produces a smooth image of the orchestra or
choral ensamble as wide as from the second violin chairs on the far
left to the percussion that is on the far right.

I do not attempt in any way to capture a stereo image that isn't
anything like the actual image in the hall.  Or to record any
additional location cues because I can already determine where the
insrtuments are located.

(texted edited)

>Another problem I had origionally is that the MDR V6's that I use
>have, on my head, no deep bass, a hump in the midbass, and no extreme
>treble.  When I go home and listen on my Stax Lambda's or my
>loudspeakers, I hear some new things, and sometimes what I hear is
>bloated bass because I picked a mic position that overemphasized it.
>This sort of problem hasn't cropped up in a while -- now that I realize
>the failings of the Sony's, I can compensate.  I can also take my glasses
>off and squash the 'phones against my head to get a better seal (I refuse
>to get a crewcut just to make better recordings!!!).

Running the risk of insulting you and your Stax Lambda's or your
loud speakers.......I have "tested" my Sony's accuracy many times.

If I can take the 'phones off and hear the same frequency response
betwen the 'phones and the live source that I am convinced that my Sony's
are accurate to within my ability to discern that difference under direct
comparison techniques.

I have two pairs of the MDR-V6's and there is a slight, barely
noticable difference between them but I still feel that they are
netural in their sound reproduction.
-- 
Chris Christensen                  The opinions I express are my own,
chrisc@gold.gvg.tek.com            and sometimes they are wrong!
916-478-3419 FAX 916-478-3887      After all, I *AM* only human.
Newsgroups: rec.audio.pro