14 Feb
2010
14 Feb
'10
12:51 p.m.
On Sun, Feb 14, 2010 at 6:31 AM, <fons(a)kokkinizita.net> wrote:
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
On Sat, Feb 13, 2010 at 10:16:24PM -0500, Monty
Montgomery wrote:
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 :-)
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 !! 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.