Hi Carlos

> I guess I didnt word my message to well. yes which filter has the most
> 'growl' but also sounds good and bassy when set to self oscillate

OK - if I understand growl right (that what a Fender Jazzbass can give),
then still it is NOT the filter - its the oscillator waveform.

Quite nice examples are the darker synth basses of Steve Winwood, or
bass of Bernard Edwards in "Your love so good to me" (yes, the bass
player of Chic did one of the greatest synth bass licks I know - and
sorry for these boring old fart examples).



Try this:
1.) Three VCOs, one with asymetric, not modulated pulsewave is very
dominating, the others are saw and triangle but each of them gives maybe
only 10% of the signal.
2.) lot of small manual given vibratos from the modulation wheel.
3.) Lowpassfilter (no matter which one) with only a little(!) envelope
amount, little resonance; filter envelope is more a longer and piano
like envelope.
4.) VCA envelope may be organ or long piano style but without release.
5.) Put some fat and nasty compressor on it (Edwards used a Urei 1176).

Now switch the compressors bypass on and off, and you will see, that
especially the compressor raises the "growl" which basically was
produced by the asymmetric pulse beating a littlebit with of the other
low leveled VCOs.

Florian