[LAD] Mixing audio: Implementing pan and balance

Tim E. Real termtech at rogers.com
Wed Mar 13 08:16:10 UTC 2013

On March 12, 2013 09:22:39 PM Fons Adriaensen wrote:
> On Tue, Mar 12, 2013 at 04:24:49PM -0400, Tim E. Real wrote:
> > Interesting about the crossover bit.
> > Wow, I considered adding selectable pan laws but didn't realize
> > crossovers.
> The rationale behind this is that at LF the L and R signals will add more
> or less in phase, while at HF the phases are random and what gets added is
> the power.
> The mixer app I've been developing has only Ambisonic panning. If you
> want stereo, you use a first order horizontal only bus (3 channels),
> use the -45 to +45 degrees range of the panner, and decode to stereo
> in the master strip. Then it's that decoder that determines the relative
> center gain of the panner, and it's no problem to make it frequency
> dependent so you get -6 dB at LF and -3 dB at HF.
> > I will look at having separate pan controls for each channel on one strip,
> > 
> >  as I'm reminded from talking to Paul that Ardour has this :)
> A2 had this, but no way to change the relative gains of L and R.
> The full matrix from L,R to L',R' has four coefficients. One of
> those factors out as channel gain, so three remain. So a really
> universal stereo -> stereo 'panner' must have three independent
> controls.

Yeah, you're right. Four factors for a two channel strip. 
Either two faders and two pans, or one fader two pans and a balance.

Took me a while of staring at the 'Panning' picture on Ardour's features 
 page. There's the missing link -  the relative gain you mentioned - which 
 is the slider between the L and R icons. 
If I may refer to that little slider as 'balance'...

I can see how the new panner would work for one channel strips too.

Very nice stuff, love the new usage of colours, shading and gradients.

Hey Paul, Robert made an Ardour stylesheet for MusE. It's... uncanny!


> Ciao,

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