Re: [LAD] Mixing audio: Implementing pan and balance

On 03/12/2013 08:08 PM, Tim E. Real wrote:

> But having said that, yes I'm wondering about a true 'stereo pan' feature.
> How would such a feature work?

there is no one true stereo pan.

a pan law for intensity stereo (i.e. a panned image or an XY coincident
microphone pair) would increase one channel and decrease another such
that the total energy remains constant. a cosine/sine law is usually
used, because

cos^2 + sin^2 = 1

ardour3 attempts to do this, by allowing you to reduce the width (by
introducing crosstalk), and then letting you move the compressed image
left or right. sort of works, but only for pan-potted stuff.

a pan law for run-time stereo (i.e. spaced omnis) would have to use
delays, leaving the original level intact.

the ardour3 panner gets this type of signal horribly wrong, because you
_never_ want to introduce crosstalk in spaced omnis - instant
comb-filtering hell.

for stereo techniques that incorporate both run-time and intensity, such
as ORTF, NOS, EBS, you-name-it, you need different amounts of gain
change _and_ delay.

that's why nobody wants to use a ready-made stereo balance control - it
is almost guaranteed to do the wrong thing for the source material at hand.

best,

jörn

-- 
Jörn Nettingsmeier
Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487
Meister für Veranstaltungstechnik (Bühne/Studio)
Tonmeister VDT
http://stackingdwarves.net
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