Double Bass Vibration With the 'A' string.

[StargazerEm]

On my school's double bass I have been hearing an odd vibration sound when playing something on the A string, while playing pizz style. This has just happened recently, after I moved the bass in a vehicle.

I don't think it's a problem with a bump in the fret board because the sound also happens when I play the A string open. The sound seems to be coming from the lower part of the bass.

Could it be the string itself causing the problem? It is obviously strained near the bridge.

When the vibration happen it feels as if there pluses going through the string underneath my finger while holding down the string as the note dwindles.

The vibration doesn't happen all the time either. Sigh... It's frustrating.

I would really appreciate a quick answers because I have a jazz camp to go to on Sunday...

(And I don't really know all too much about double basses.)

 

[DoubleMIDI]

Don't worry about that buzz at the jazz camp, a little buzz here and there is some spice to the music...

Try to get another person to play some notes on your bass and listen closely at the instrument where the buzz is located (or change the role of player and listener).

It could be the string, specially as it happens on different notes. If the winding broke at the bridge such a buzz could happen easily. I would try to change the A string first and hear if the buzz is still there. And when you have the string down look if the string slots in the bridge are rounded and wide enough for the string and lubricate it with graphite from a very soft pencil when they are OK. otherwise round and/or widen the string slot before lubricating and mounting the new string. (It makes sense to do this to all four string slots, one after the other.)

If it would have been on certain frequencies only (independent of the string they are played) I would think there is something loose (screw, wood, ...), but this seems not to be the case. Sometimes it is something simple as the endpin screw or peg screw being loose...

 

[StargazerEm]

Thank you! The winding is breaking at the bridge. So I think I need a new string...

 

[DoubleMIDI]

If you have a steel core string (but only then!) you can get a piece of shrink tube (electronics store) that is just a bit larger in diameter than the string diameter andput some length of it over the position of the break (if the break is clearly visible at the outer surface of the string). Then heat the tube up unless it shrunk around the string. Put it back on the bass (I know the diameter is larger now, but simply ignore that) and tune it up. If you are lucky the buzz has gone and you can use the string as long as you don't have a replacement string.
I rather use this if something like that happens at the pegbox part of a string, but should work at the bridge too. THe string might become a bit more damped that way.

 

[StargazerEm]

I don't know what the strings are since they've been on for before I used the bass so to be safe I'll just tough it out until I get new strings.

 

[DoubleMIDI]

IF you can tell us the silk colours at the tailpiece and the pegbox and maybe also the shape of te ball end (cylindric, barrel, rod) someone may be able to tell you what kind of strings you have. It might be helpful to know this for the decision of a new set of strings (so they are not too hard in tension for you).
If you cannot get shrinking tube, any other flexible tube slightly larger in diameter over the damaged part will help that the windings don't get worse. Even a piece of rubber tube for an old type bicycle valve would do it, but might damp a bit more because of its softness and thickness.