From: chrisc@gold.gvg.tek.com (Chris Christensen)
Newsgroups: rec.audio.pro
Subject: Re: L-C-R Panning Survey
Date: 7 Oct 92 01:17:12 GMT
Organization: Grass Valley Group, Grass Valley, CA

In article <BvoGF6.J9v@world.std.com> muller@world.std.com 
(James L Muller) writes:
>In <1992Oct5.222500.18015@guinness.idbsu.edu> Dave Jensen
>   <djensen@claven.idbsu.edu> writes:
>>Q.  Assuming you had access to the three clusters, would you value the
>>ability to have true Left-Center-Right (L-C-R) panning and output
>>capability? (This means when then the channels pan control is panned to
>>center no signal goes to either left or right outputs; if panned to hard
>>left, there would be no signal to center or right outputs; halfway
>>between center and left would result in equal output to left and center,
>>etc.) Please briefly qualify your answer.

Gee somehow I missed the original posting on this.....

Yes I would value this mode of operation and use it.  Ramsa has a
console that has this feature already designed in.

I have done SR for concerts as well as theater out of doors and in
cases where I have done it in stereo only I have been disapointed
except for when I have provided the means for a good solid center
image.

>I can think of several problems with this, just from a pragmatic point of
>view, not to mention the cost of a third amp and speaker cluster and the
>problem of where to put it.  (Speaking of live-show mixing, of course.)

Sorry James,  you missed the point of the posting.  Dave was asking "...if
you had all the equipment to do it,  would you value it?..."

>One is that there already is a problem with how some mixers pan.  In
>the usual (i.e. less expensive?) system, when you pan to one side, the
>opposite is attenuated, but that side is not boosted.  The problem is
>that if you ever pan to the middle, there is a 3 dB boost of that channel.

Missed it once againo Dave carefully explained what he was talking about.
He correctly described L-C-R panning,  not to be confused with L-R
panning.

>This means you may have to change your mix as a result of re-panning
>something.  It's a minor point, but your system could make it worse.

Here is a _good_ point.  The possiblity of doing a "bad" mix using a
L-C-R system is higher than if it were a "plain" stereo mix however an
experienced balance engineer would be able to adapt quickly!

>The second problem is one of when to use and when not to use stereo anyway.
>The precedence effect can make the closest speaker seem like the source
>of the sound unless panning is extreme.  The problem then is that if you
>don't pan enough, or if the speakers are too far apart compared to the
>audience seating, then a lot of people just won't hear any stereo effect
>at all.  Instead of creating a stereo effect, panning just makes everyone
>closer to one speaker hear one mix and everyone closer to the other speaker
>hear a different mix. 

Another good point.  This is the primary reason I will use mono for my
large venue jobs.  I have a system where I can split the feeds to the
speaker stacks and have a R-L coming out of the "left" stack and R-L
coming out of the Right stack.  This is done with a splayed array, of
course.

>Adding a center channel won't help this, and in
>general will make the entire phenomenon harder to figure out.  When do
>you want stereo and when don't you want it??  I must admit I haven't
>really spent much time thinking about this, but it seems to me that your
>system won't help much.  Then too there is the option of taking the L+R
>sum and driving a third (center) cluster.  It won't be quite the same
>because the options of L+C or C+R won't be there...  Interesting...

I guess I am missing the rest of the post because I didn't read
anything that Dave said the proposed the L-C-R as any king of solution
for any problem.

The criteria I use to determine if I use mono or stereo is based on
what my audience want's.  If I am doing a classical concert I am more
inclined to do the SR in mono because classical audiences are usually
more sensitive to mix. ie if you are sitting in the audience far stage
right you will hear mostly the violins and little cellos because
that's how it's panned.

If I am doing a rock or country show then I do stereo for the most
exciting effect.

The use of center fill and other non-Left/Right mixes has/is done
every day of the week somewhere usually with a matrix feed or a
"spare" bus.

Please excuse me for correcting you in public.  I would have prefered
via direct Email.  I hope that you don't mind too much......

The topic *is* interesting and I look forward to the discussion.
-- 
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.