Double Bass bridge alignment > sound

Maple

Maple

Supporting Member
Feb 25, 2016
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San Francisco Bay Area
#1
Several months ago, I started getting really frustrated with the sound I was getting from my bass. I had previously dialed in a Yamahiko and Ischell combination. Rooms I used to sound good in, I was now struggling with nasal sounds that I had to notch out. I had also been messing with strings and wasn't sure if it was just the strings. I was getting weird resonances around A 220 Hz
Last month, I took off the Ischell out of frustration, only to put it back on, again out of frustration.

And then last week, I noticed the bridge feet weren't sitting properly on the top! The top of the bridge was maybe a cm closer to the nut than it should have been so the feet were sitting on edge. Hmm. I must have bumped it or maybe was careless when swapping strings.

I set the bridge back to where it should have been and immediately, the resonances seemed to be gone. I played in a couple ensembles a few days after that and the tone was great once again! Then last night, another room that I usually struggle in was also just good and solid.

It's incredible what a little thing like that can do.
 
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#2
I've had this experience a number of times. It can occur if the bridge starts to lean toward the fingerboard, and also if the bridge gets knocked sideways so that it moves the strings toward either the bass or treble side of the fingerboard.

The "paper test" is a good thing to get the feel of. It consists of trying to slide a piece of paper under all four sides of the bridge feet to see if there is any tilt that might not be apparent to the naked eye. If you find tilt, there are a number of ways to correct it. Some people loosen the strings to correct it, while others gently whack the bridge back into place under full tension with some weights object. I'm in this second group, and for some reason my tool if choice is the spine side of a Kurt Vonnegut paperback novel. I don't know why, but it's important to me that it be Vonnegut. :D

There's also another thing I encountered with an old bass I used to have that involved the relation of the bass foot to the bass bar. If the strings were perfectly centered on the FB, the bass response suffered. But if i moved the bridge over a few mm to the bass side, the E string roared. I suspect that the bridge was too narrow, but back then I didn't think of this and just kept it skewed toward the bass side a little. To this day, while I understand that luthiers is a science to those who work on basses often, it remains about 50% voodoo to me.
 
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#3
Timely thread for me. My bass had been feeling really "off", the g string way too low and the E and A very stiff and higher than usual. I was concerned that the top may have sunk a bit or ?. I played with string heights which helped a little. Everything looked ok, but I decided to bring the bridge closer to the G string side. A couple of nudges, maybe 1/16-1/8" and bingo, all was back to normal.
 
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#4
Chris Fitzgerald said:
I've had this experience a number of times. It can occur if the bridge starts to lean toward the fingerboard, and also if the bridge gets knocked sideways so that it moves the strings toward either the bass or treble side of the fingerboard.

The "paper test" is a good thing to get the feel of. It consists of trying to slide a piece of paper under all four sides of the bridge feet to see if there is any tilt that might not be apparent to the naked eye. If you find tilt, there are a number of ways to correct it. Some people loosen the strings to correct it, while others gently whack the bridge back into place under full tension with some weights object. I'm in this second group, and for some reason my tool if choice is the spine side of a Kurt Vonnegut paperback novel. I don't know why, but it's important to me that it be Vonnegut. :D

There's also another thing I encountered with an old bass I used to have that involved the relation of the bass foot to the bass bar. If the strings were perfectly centered on the FB, the bass response suffered. But if i moved the bridge over a few mm to the bass side, the E string roared. I suspect that the bridge was too narrow, but back then I didn't think of this and just kept it skewed toward the bass side a little. To this day, while I understand that luthiers is a science to those who work on basses often, it remains about 50% voodoo to me.
Click to expand...

"Catgut Cradle," no doubt.
 
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#5
To move the bridge, I like to reduce the tension a bit. Without detuning, I just pull the E and G strings off so they run slack against the wings. This keeps enough tension to move the bridge about, by hand, without is slipping. But next time, I’ll try the tapping method. For that, Vonnegut is a great choice - I find his books good for putting things into alignment. I also have Henry Miller on the shelf next to his. I might have to experiment with both.
 
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#7
Gary Upton recommends grabbing the strings with your finger and pushing the bridge top with your thumb, while holding the bridge bottom with the other hand. I've done it to my rental bass without problem:

 
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#8
Maple said:
To move the bridge, I like to reduce the tension a bit. Without detuning, I just pull the E and G strings off so they run slack against the wings. This keeps enough tension to move the bridge about, by hand, without is slipping. But next time, I’ll try the tapping method. For that, Vonnegut is a great choice - I find his books good for putting things into alignment. I also have Henry Miller on the shelf next to his. I might have to experiment with both.
Click to expand...

If you want the nexus to perplex us, Miller's the guy.
 
#9
Chris Fitzgerald said:
I've had this experience a number of times. It can occur if the bridge starts to lean toward the fingerboard, and also if the bridge gets knocked sideways so that it moves the strings toward either the bass or treble side of the fingerboard.

The "paper test" is a good thing to get the feel of. It consists of trying to slide a piece of paper under all four sides of the bridge feet to see if there is any tilt that might not be apparent to the naked eye. If you find tilt, there are a number of ways to correct it. Some people loosen the strings to correct it, while others gently whack the bridge back into place under full tension with some weights object. I'm in this second group, and for some reason my tool if choice is the spine side of a Kurt Vonnegut paperback novel. I don't know why, but it's important to me that it be Vonnegut. :D

There's also another thing I encountered with an old bass I used to have that involved the relation of the bass foot to the bass bar. If the strings were perfectly centered on the FB, the bass response suffered. But if i moved the bridge over a few mm to the bass side, the E string roared. I suspect that the bridge was too narrow, but back then I didn't think of this and just kept it skewed toward the bass side a little. To this day, while I understand that luthiers is a science to those who work on basses often, it remains about 50% voodoo to me.
Click to expand...

You have good taste, sir. I use “Looking at the Double Bass.” Should we start a thread on how different books we use to whack the bridge back into position affects tone?
 
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