MOTM

Dave Bradley (09:42 AM 10/5/1999) wrote:

 >> Intresting stuff, can be done with a parametric eq, but as with all
 >> filters, the sound will depend on the actual circuit used and there
 >> are plenty of variables here :)
 >
 >The MOTM 420 is 3 resonant bandpass filters. Fixed resonance, but
 >individually tuneable filters so you can do similar interesting things. I
 >plan to use mine a lot for formant types of things, not just swooshing
 >around with the LFOs.

Is someone was gonna go nuts on a filter bank, my vote is for a full 
Formant filter. I have a custom 4-band in my Moog modular, and it's awesome.

(I know you know this Dave, but...)

A Formant filter is basically a number of bands (4 is common, I've seen 
overkill at 8) where each band has a variable center freq, a cut/boost 
control, and a fine control for resonance - usually a 10 turn pot.

The point is to mimic the nasal sounds of the oral cavity. The 10-turn pot 
on resonance is required in order to be able to hang the filter stage 
*right* on the edge of feedback - RIGHT on the edge.


 >> I am not too familiar with these other "fixed filter banks" .  What
 >> are the controls per section/band, if freq is fixed, what center
 >> frequencies are used ?
 >
 >The Moog fixed filter banks are fixed frequency AND resonance, so no better
 >than a common graphic eq. Just a gain control for each band. If I remember
 >right, there is an 8 band and a 12 band version, each with an additional low
 >and high shelving control.

I remember the Moog filter bank being only cut, no boost. Sweet sounding 
stages though. :)


Mark