On Nov 4, 11:30 pm, "Stacy" <stacy2003_yo...@yahoo.com> wrote:
> I want to implement a graphic equalizer in S/W.
> I assume it is a bunch of bandpass filters with boost/cut at their
> respective frequencies.
> Has anyone else done this or know of any links?
Digital Stereo 10-Band Graphic Equalizer Using the DSP56001
Application Note APR2/D, Motorola Inc.
I can't find it on the Motorola or Freescale web site, but
there seems to be a copy available here:
Reply by robert bristow-johnson●November 6, 20072007-11-06
On Nov 5, 3:53 am, "mnentwig" <mnent...@elisanet.fi> wrote:
also, if the word width is wide (and i think 32-bit fixed is pretty
good, and the native double-precision is more than wide enough), then
you can implement the Graphic EQ as a cascade of the parametric EQs (i
might call it "peaking EQ" since, i think the language supports the
shelving filters as a class of "parametric EQ") with fixed frequencies
equally spaced apart in log frequency (and with the parametric EQ
bandwidth nearly equal to that spacing). this is an alternative to
the parallel BPF each centered at these fixed frequencies with gains
attached to each. i believe the parallel BPF structure gets less
noise (most certainly if the untruncated double-precision output of
each BPF is added before rounding) then the cascade structure. this
is why i tossed in the word width caveat.