Problems with uneven and boomy sound using RS II

[hgrind]

I'm using the Upton RS II on my upright bass. I run it through a Phil Jones Bass Buddy to the mixer. I get a little boomy sound sometimes and the sound is very uneven across the register. I can hear what I play on the E, A, D strings and an open G, but as I move up the G string, the sound disappears more and more, and I'm not able to hear what I play in my in-ear monitor or through a PA-system. My bass is very even across the register, and if the acoustic sound would be reproduced when amplified, this shouldn't be a problem.

What could be wrong? I'm not very good with technical stuff, eq etc.

Thanks in advance for any help!

[drurb]

Originally Posted by hgrind

I'm using the Upton RS II on my upright bass. I run it through a Phil Jones Bass Buddy to the mixer. I get a little boomy sound sometimes and the sound is very uneven across the register. I can hear what I play on the E, A, D strings and an open G, but as I move up the G string, the sound disappears more and more, and I'm not able to hear what I play in my in-ear monitor or through a PA-system. My bass is very even across the register, and if the acoustic sound would be reproduced when amplified, this shouldn't be a problem.

What could be wrong? I'm not very good with technical stuff, eq etc.

Thanks in advance for any help!

If you get a boomy sound only "sometimes," it sounds like the fit of the pickup is variable. It should be quite snug but movable. Too loose is not good, too tight is not good. If it is a bit too loose, a single layer of scotch tape over one (or two) surfaces can work wonders. If it is too tight, further sanding is in order.

The sound will also vary as a function of which side of the pickup is facing up. Try flipping it over. A less-boomy sound should be achieved with the "R" facing away from the body.

The RS II definitely has a "sweet spot." Change the position of the pickup slightly until you find it. After you do, I suggest marking the pickup with a pencil so that you can return it to that position.

Be sure to use the "passive" input on the Bass Buddy. That is the one that the manual lists as having a 4M-ohm input.

Hope this helps.

[bolo]

All of drurb's advice and hints are excellent. +1 to everything he said. And in addition:

The Highs

How is the EQ on your preamp and the PA set? If the volume declines as you go up the G string, I wonder if one or both of the EQs have the bass and/or low mids boosted or the highs cut. This may not apply in your situation, but IME it seems like some soundmen like to simply boost lows and cut highs for any "bass" instrument they come across.

The Lows

IME the RS II like many other piezos can really pick up a lot of infrasonics (even after the redesign from the RS I). Especially like in my case when you have the p/u flipped over with the "R" symbol facing the bass. A high pass filter will give you better control over that low end boominess.

[hgrind]

Thank you!

I'm going to look into the fitting into the bridge again. I think it sits quite tight. I have to loosen up the E-string to move it.

I'm aware of the not boost lows and cut highs thing, but I don't think I follow it all the time.

I'll try the things you have suggested.

[bolo]

Originally Posted by hgrind

I have to loosen up the E-string to move it.

Wow. That is VERY tight in my view.

Be patient. The problem with sanding the bridge or the pickup is that if you go too far and the p/u becomes too loose, then you have to start thinking about using shims or getting the pickup reconditioned (i.e. new wood casing).

I should know. I have fit three (or four?) different RS's on the same bridge seeking that optimal fit and tone.

[drurb]

Indeed, it seems the pickup is far too tight. This tends to "choke" the piezo element. As bolo suggested, easy does it on the sanding. Go very slowly. In my experience, when the RS II is fit correctly, it will not move on its own even when the case is taken on and off but it will be loose enough so that you can move it with your hand.

Thanks to bolo for the high-pass filter suggestion. As an ardent supporter of using one with piezos, I can't believe I neglected to mention it! I suggest that you get hold of one of fdeck's little HPF/Pre-amp gems.