Hello Robert, sorry for the late answer, hope this helps nevertheless! > I spent a very long time trying to get the multi band processor shown > in man sox to work. > It seems the manual is older then the code which has changed. Hmm. I am in currently rewriting some of the SoX code for (open-source) SoX-VST-Plugins for DAWs (with bit-exact identical behaviour to the command-line version) and as far as I can tell, the compand and mcompand parameters work as described in the manual. > I needed a processor that would take audio from various not so great > sources, adjust the dynamic range to suit a talk radio stream, and try > and correct the frequency balance. One source consistently has poor > room acoustics. Another has levels that vary wildly and a range of > audio frequency bandwidths. > > compand works as advertised. Perhaps not that clearly. > mcompand does not work as implied. It does some of what mcompand does > but not all. I find the transfer function definition in SoX a little bit weird, but it is extremely flexible. You do not define some compression ratio or some compression threshold directly, but define base points of that function. Your functions look okay, but you could consider rounding off the corners of the transfer function by adding a knee value of e.g. 4dB. > I would encourage comments suggestions and improvements. What you could do is factor out the common parameters and just put in the changed values instead; you already did that in part, but putting this further would make your script more modular. As far as I can see, your transfer functions, gain and initial volumes are very similar for all of the bands, hence the modular approach could be helpful. The crossover frequencies look okay for me. I find your release times of 1.2s or even 2.0 quite extreme, but if they work for your sound material, that's fine. Hope this helps! Best regards, Thomas _______________________________________________ Sox-users mailing list Sox-users@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/sox-users
