On Sun, Feb 14, 2010 at 6:31 AM, <fons@xxxxxxxxxxxxxxx> wrote: > On Sat, Feb 13, 2010 at 10:16:24PM -0500, Monty Montgomery wrote: > >> I'm aware of how to construct digital IIR filters :-) I was hoping >> you had a URL to a nice official analog topology. The specific >> implementation details matter. > > I'll make a nice drawing later. Right now I have > to finish my LAC paper !! Uh, I was hoping for an official recommendation from the spec, not an intuited circuit that works. I didn't know of any officially recommended one, but the way you were talking about it, I thought you did. Either from the original only sort-of-standard RIAA curve or the eventual IEC specced version. I don't need a schematic of a simple RC bandpass, thanks :-) >> > The channel EQ you'll find on most digital mixers is >> > not linear-phase at all, nor acausal. >> >> OK. Time to become incredibly overspecific: >> >> Every digital EQ implementation I'm aware of for Linux is linear >> phase. I wrote a few of 'em. > > The only examples I know of are the FFT based EQ > in Jamin, and the octave band filters that come > with jconvolver. Uh, those are linear phase and acausal. Also beware of JAMin's using the FFT for non-time-invariant effects, it will modulate the audio that passes through. Not a problem for FFT, huge problem for things like compressors. Monty _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
