Double Bass Adjustable Bridge - high and low sides out of sync

[sean_on_bass]

What causes this to occur, in that over time after a setup is done, both sides of the bridge have migrated up or down in height non-proportionately? For instance you find yourself having to raise one side drastically to retain a consistent string height over all strings.

This has occurred on my bass, and after changing from a medium to light tension string has "put the nail in the coffin" so to speak. My G side is maxed out high and E side is maxed out low, and i still have the G side too close to the board for comfort.

I'm guessing this is about the time a setup is warranted from a luthier, but i am new to owning a bass. What causes this, is it normal, and do i just need to go in for a setup to fix it? Will a new bridge be needed?

 

[DoubleMIDI]

Is the bridge centered? I mean same amount of space outside the E-string and G-string towards the edges of the fingerboard at the end of the fingerboard?
The bridge might have been rocked towards the G-string side which can result in a situation you have described. Put the bridge back towards the E-string side if this is the case. This frequently happens during transport if the bridge was knocked insid the bag by accident.

 

[Chris Fitzgerald]

This used to happen to me all the time. As mentioned above, the bridge has probably been whacked over toward the G side. It doesn't take much, but once it's moved, everything feels wrong. How much free/empty board do you have out the outsides of your G and E strings at the end of the board? Is it unbalanced?

 

[Don Kasper]

What causes this to occur, in that over time after a setup is done, both sides of the bridge have migrated up or down in height non-proportionately? For instance you find yourself having to raise one side drastically to retain a consistent string height over all strings.

This has occurred on my bass, and after changing from a medium to light tension string has "put the nail in the coffin" so to speak. My G side is maxed out high and E side is maxed out low, and i still have the G side too close to the board for comfort.

I'm guessing this is about the time a setup is warranted from a luthier, but i am new to owning a bass. What causes this, is it normal, and do i just need to go in for a setup to fix it? Will a new bridge be needed?

You should stand behind the bass and sight down the fingerboard by leaning the bass back, and look down the fingerboard, starting from the scroll toward the bridge. The bridge should appear to be visually centered (equal amounts of overhang on either side of the fingerboard), to the end of the fingerboard - that is, if it was properly installed.
If not, (place the bass on its back), partially loosen the strings and gently tap/move the bridge so that it is centered at the end of the fingerboard - again, sight from the scroll to the bridge, while leaning the bass back.
Also, check that the tailpiece cable is centered at the saddle (the small piece of wood at the lowest part of the top - where the tailpiece cable bends and heads toward the endpin.)
It may be time for a new bridge if this geometry is out of alignment (or, was never properly considered when the bridge was installed.)
Thanks and good luck.

 

[Mgaisbacher]

Also if the G side is maxed out high and the E is maxed low then it may actually be causing your G to be lower and E higher. It seems counterintuitive but it happened to one of my previous basses and Arnold Schnitzer pointed it out to me.

Since the fingerboard is an arch and so is the bridge, if the adjusters are much different then each other it makes the center of the top of bridge off center of the peak of the radius of the fingerboard, which moves the G string closer to the E side of you bass, which is actually making the G lower and E higher since its moving the G towards the peak of the FB and the E away from it, even if the feet are in the correct positions. I would suggest making them both the same and make slight adjustment away from that, if the are 1 or 2 turns different then each other then it won't make much of a difference but if they are bot about maxed out opposite of each other then it will have a major effect.

Hard to explain in words but hopefully it makes some sort of sense.

If when the adjusters are even and the string heights are still not what you want them then you may need the top of the bridge reshaped, that is if there is enough wood to take off.

 

[Chris Fitzgerald]

The above is absolutely correct - you may have actually compounded the problem by adjusting the wheels the way you did. Using the adjuster wheels on a bass is like backing into a driveway with a trailer: to get the trailer to go where you want, you have to turn the wheel of the car in the opposite direction. It takes a while to get a feel for it.

I would suggest making them both the same and make slight adjustment away from that, if the are 1 or 2 turns different then each other then it won't make much of a difference but if they are bot about maxed out opposite of each other then it will have a major effect.

Absolutely right. Once you have them even or thereabouts, then would be the time to check the amount of free board on the outside of the G and E. If my bass were too low on the G and too high on the E, I'd set the wheels even and scoot the bridge gently toward the G side and let the radius of the board do the adjusting. It's amazing the amount of difference even a millimeter or two can make.

 

[bassmanbrent]

Yup, +1 for what was said above about adjusters. You should probably even them out to see where you are at, move the bridge, if necessary, and then raise the bass bar side adjuster to raise the g string height. Raise the sound post side adjuster to raise the e string height if you need to. Seems totally backwards, but that's how they work.

 

[DoubleMIDI]

It might also be possible that
A) the bridge sits in the wrong orientation (E-side bridge end at G-string and vice versa)
or
B) the bridge feet have been mixed up when the bridge was down earlier.

 

[Povl Carstensen]

I have a small mark on each of my adjusters, and try to always keep them "in sync".

 

[sean_on_bass]

THANK YOU all for the suggestions, i am going to work with the bass later today. The comments about the radius and raising one side to adjust the other makes sense, and was something i was thinking about while doing it but couldn't completely conceptualize how it was happening in my head. I'll try to bring both sides to even position and see where i am from there, as well as measuring board end to bridge on both sides to make sure the distance is in balance as well. Will let you know how it pans out.

 

[Chris Fitzgerald]

Also, in my experience, having the bridge set to where the string heights are more playable and comfortable for you is more important than a slight off-ceneteredness of the bridge in relation to the fingerboard. A luthier can fix this later, but you have to play it between now and that point.

 

[bassmanbrent]

Also, in my experience, having the bridge set to where the string heights are more playable and comfortable for you is more important than a slight off-ceneteredness of the bridge in relation to the fingerboard. A luthier can fix this later, but you have to play it between now and that point.

Further to this, if the neck of your bass was installed a little off centre (i.e. not perpendicular to the body), and apparently many have been, you'll likely need to have the bridge a little closer to one F hole than the other in order to have it centered relative to the fingerboard. In other words, having your bridge perfectly centred between the F holes might not actually be the best spot for it. You may need to tweak it slightly to one side or the other in order to centre it in relation to the fingerboard.

 

[Ortsom]

Indeed, but while the post could move with the G-foot, the E-foot best loads directly onto the bass bar to prevent top deformation. In such a situation, where the FB is not centred over the top, consider either offsetting the notches in the crown, or using a wider (FB --> G side) or narrower (FB --> E side) bridge.

 

[sean_on_bass]

Hey all. So i went ahead and evened out both sides of the adjustable bridge and it largely fixed the issue. Haven't even bothered measuring it yet because it felt so much better. I'm thinking i simply got on a tangent of trying to raise or lower each side, one at a time, over the last year. This resulted in the current situation.

I do notice my light gauge G string is significantly thinner than the medium gauge G i had on before. I think this created a bit of illusion as to how high the string feels off the board.

Thanks again for all the great advice.