HPF/LPF built into a bass?

[Pat Harris]

I have a Muckelroy fretless bass guitar with his Muck preamp in it AND a passive tone control.

The bottom end is wide open, so I use an external HPF for that. However, when running it in active mode, there is some magic that can happen between the passive tone knob and the high band of the preamp. Basically, you can create a nice little resonant Q up top if you pull the passive tone down and then bump the treble control up. I like this a lot, because you can still get those high mids in the 2-4kHz "attack/envelope" range, but then lop off the hissy wide open high-highs.

Pretty sure nobody in the band or crowd cares or notices, but it's something I like.

 

[The Rage]

I think the Tonepump pre in the euro Spector basses have a built in HPF at 40hz

 

[brianrost]

the roll-off isn't nearly as steep: just 3 dB/octave for passive vs. 12+ dB/octave for active.

Actually 6dB/octave. Audio filters are 6dB/oct per pole, most passive filters are single pole (one resistor/capacitor pair) but they may be cascaded for more poles and steeper rolloffs.

 

[fermata]

Actually 6dB/octave. Audio filters are 6dB/oct per pole, most passive filters are single pole (one resistor/capacitor pair) but they may be cascaded for more poles and steeper rolloffs.

D'oh! Thanks for setting the record straight! I had 6dB/octave in my head and then second-guessed myself.

Speaking of cascading filters, I once put together a two-pole passive HPF. If anyone is looking for the proverbial 'suck knob,' that'll do the trick!