Comb filtering/phase cancelation question...

[Claymore]

Correct me if I'm wrong but from what I understand, when two pickups are in parallel and in the middle notch at 50/50, there is comb filtering which results in a mid-scooped effect. Sounds amazing when playing solo but doesn't really cut through in a mix. Somewhere along the line, I remember reading that if you wire a capacitor in a certain way to one of the pickups, it will stop this from happening. You will be able to have your blend at 50/50 with no phase cancelation. Did I imagine this in a dream?...or is this a real thing? If it is possible, how do I wire said capacitor? Up to this point, I have just been slightly favoring one pickup over the other to avoid this, like 55% neck/45% bridge pickup. Thanks in advance.

 

[sunbeast]

You are likely referring to something like the Rickenbacker “vintage tone” capacitor found on all 4001 basses and available on a switch on modern 4003 basses. It is a small value capacitor placed between the hot lead of the pickup and whatever comes next in the signal path (volume, tone or blend). It affectively cuts some of the bass from the bridge pickup, but also eliminates some of the phase-cancellation when blending pickups.

The Rick value is a .0047uf capacitor, but this cuts quite a bit of bass from the bridge pickup (probably even more so on a bass with a pickup closer to the bridge than a Rick, so that a soloed bridge pickup may not be useable any more). You can experiment with any larger value (somewhere between the .0047uf up possibly as high as .1uf) to find the ideal compromise of bridge pickup tone loss vs blended pickup tone advantage. You could also put the cap on a switch like the Rickenbacker method so that it could just be engaged when blending pickups.

 

[Claymore]

That is helpful. I'm going to experiment with this as I love adding switches on my instruments that may or may not be an improvement.

 

[Claymore]

Phase cancellation?

Being as you just mentioned this in another thread, I figured you might be the guy to ask. Would you care to weigh in on this?

 

[fermata]

I've experimented with a few different values, and .01uF in series with the bridge pickup seems ideal: it improves the blending while not totally wiping the bass frequencies. (Larger values don't improve blending as much.) Granted, the bridge pickup will sound a bit thinner soloed; put the cap on a switch for the best of both worlds.

 

[Claymore]

I've experimented with a few different values, and .01uF in series with the bridge pickup seems ideal: it improves the blending while not totally wiping the bass frequencies. (Larger values don't improve blending as much.) Granted, the bridge pickup will sound a bit thinner soloed; put the cap on a switch for the best of both worlds.

Thanks for the tip. I think I'll do exactly that.