On March 12, 2013 09:56:15 AM Fons Adriaensen wrote: > On Tue, Mar 12, 2013 at 01:23:02AM -0400, Tim E. Real wrote: > > I noticed our app uses this pan formula: > > vol_L = volume * (1.0 - pan); > > vol_R = volume * (1.0 + pan); > > > > where volume is the fader value, pan is the pan knob value > > which ranges between -1.0 and 1.0, and vol_L and vol_R are the > > factors to be applied to the data when sending a mono signal > > to a stereo bus. > > > > When pan is center, 100% of the signal is sent to L and R. > > At pan extremities, the signal is boosted by 3dB. > > 6 dB actually.
Sorry I thought the wiki pages were referring to power so I expressed it as power. > > > But according to [1], we should be using a Pan Law [2], > > > > where pan center is around 3dB to 6dB down and pan > > extremities is full signal. > > There are two independent issues involved here: > > 1. The attenuation at the center w.r.t. to extreme L and R. > 2. Whether the center or the extremes should be 0 dB. > > (2) is very much a matter of taste and of virtually no practical > consequence : you will adjust the fader (channel gain) to get > the right balance anyway. > > Regarding (1), if you take psycho-acoustics into account you'd > want -6 dB at the center for low frequencies and -3 dB for high > frequencies, with a gentle crossover at around 500 Hz or so. > So the SSL compromise of -4.5 dB makes sense. > Note that unless you use the panner to move a sound around > during a mix, all of this hardly matters: you will adjust > the balance anyway and compensate for whatever the panner > is doing. > > Returning to (2): for a panner (mono -> stereo) I'd prefer > 0 dB at L and R. For a balance control (stereo -> stereo) > I'd prefer 0 dB at the center position. OK thanks. Makes sense to me. That obeys the pan rules. Interesting about the crossover bit. Wow, I considered adding selectable pan laws but didn't realize crossovers. 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 :) Tim. _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/listinfo/linux-audio-dev
