Low pass filter would be any type of band-pass filter that acts as a hard cut

The statement is false.

 

A Low Pass Filter is not a Band Pass filter.

 

The West coast looks like a high pass filter.
The high frequencies are on solid ground.
The low frequencies drop off into the Pacific Ocean.

The East coast is a low pass, low frequencies are up, high's fall off into the Atlantic.

A bandpass filter looks like Devil's Tower.
A certain range of frequencies are up, or pass, and everything on either side falls off in level.

A low pass filter needs an accompanying, and overlapping high pass filter to be a bandpass. So to speak.
Hard cut describes how fast the frequencies fall off in a given filter.
It has nothing to do with the type of filter.

You must have read this on the internet because it throws around just enough tech buzz to sound plausible to the uninitiated. Good catch on your part to think it wasn't right.

 

So what's the issue with it?

 

Loose pickup or PU hardware?
Loose hardware elsewhere transferring to the strings?

 

A Low Pass filter lets low frequencies pass through.

A Band Pass filter lets a certain bandwidth of frequencies pass through.

A High Pass filter lets high frequencies pass through.


The cutoff frequency determines at what frequency the signal is cut off, and attenuated (so in the case of a Low Pass filter, it determines the point at which high frequency content will begin to attenuate. In the case of a Band Pass filter, it determines the centre frequency around which both high, and low frequencies will begin to attenuate. In the case of a High Pass filter, it will determine the point at which low frequencies will begin to attenuate.)

The rate at which the attenuation will occur, is determined by how steep the filter is - commonly ranging from a gentle 6dB per octave, through 12dB / 18dB, to a very steep 24dB per octave.

The steeper the filter, the more harsh and aggressive it's resonant peak is likely to be.

The Resonance, or Q control determines how pronounced the resonant peak is, in the case of both High, and Low Pass filters. But on a Band Pass filter, it determines the width of the frequency band - or bandwidth - around the centre frequency (as set by the cutoff point), either side of which, low & high frequencies will be attenuated.

Hope that clears things up.

 

Try raising your action - your strings will be both further away from the pickup, and you will have less fret noise/clack. If you don't like high action, at least you will know if the problem is pickup height. Was your old pickup lower?

Have you tried other strings? Some strings are more clacky than others...

I don't think electronics are your problem, but maybe check if you have 250K pots. I'm not sure what pots work best with stacked pickups, but some single coils can sound harsh with higher value pots.

 

It would probably help your problem to some extent, but not necessarily solve it. For starters, just open the control panel and check the values (if you don't know them from memory). If you have two 500K pots, it's easy to test the sound difference - just clip a 250K resistor between the tip (hot) and the sleeve (ground) on your output jack. You can try a few resistors with different values, maybe between 100-500K.

A somewhat different approach would be to clip a relatively small capacitor (maybe 1000 pF) in the same place. While pot resistance helps dampen the resonant peak, capacitors move the peak to lower frequencies. It's a different kind of effect, but if you're trying things, it's worth experimenting to see if it helps. Again, try a few different values, maybe 330-2200 pF.

It's just a few bucks to get a couple different resistors and capacitors + alligator clips at an electronics store.

I only have experience with SCPB-1 and it sounds good. Not metallic, but warm. SCPB-3 (quarter pounder) has it's fan base around here too. What pickup was in the bass before you replaced it with the stacked Duncan?

 

I don't know if I have experienced any type of clacking with any of the pickups mentioned. I wonder if it could be the type of strings, or something electronic that is off....
Are you talking clacking like Steve Harris, or what...I am having trouble envisioning what is going on here.