Double Bass What does a bass bar problem sound like?

[victorvran]

I just picked up an old German plywood shop bass, and when I finally got it home, started to notice a buzz. It comes and goes, but when it's there it almost sounds like the bass is played through an overdrive pedal.

I have spent the last two days reading bass bar horror stories, and I want to know what a bass bar problem sounds like. Apologies if this is a repeat thread, but I couldn't find this info anywhere.

So far, when the buzz is there, it's on almost every note. The top is a little bit sunken in by the bridge, but from what I understand this is fairly typical of old plywood basses. It seems to be stable. When I place a finger inside and pull the top up (away from the back) the buzz seems to go away. I can't find any glaring seams, and it isn't long endpin buzz. Bass bar? Sound post?

Any ideas?

 

[Matt Liebenau]

You might have better luck on the double bass side. Hope you get it worked out.

 

[victorvran]

Oh man, long time bassist...noob-ass poster. I'll move it, thanks!

 

[Steven Ayres]

The top is a little bit sunken in by the bridge, but from what I understand this is fairly typical of old plywood basses.

Table sinkage not an uncommon problem, but rather than being inherent to old plywood, it generally comes from poor maintenance, particularly soundpost mishaps. With a failed bass bar you will generally be able to see deformation of the table under tension, usually more toward the failed end of the bar but possibly near the bridge as well.

Get hold of a dental or mechanic's mirror and a good light, and take a look through the f-holes.

 

[victorvran]

Table sinkage not an uncommon problem, but rather than being inherent to old plywood, it generally comes from poor maintenance, particularly soundpost mishaps. With a failed bass bar you will generally be able to see deformation of the table under tension, usually more toward the failed end of the bar but possibly near the bridge as well.

Get hold of a dental or mechanic's mirror and a good light, and take a look through the f-holes.

Thanks, I definitely plan on that...but what am I looking for? If it's loose, will it be visibly so?

 

[Steven Ayres]

If it's loose, will it be visibly so?

Because of the downward force, you will probably be able to see space between the bar and the top.

 

[Turnaround]

A loose bass bar can cause the kind of buzz you are experiencing. If you tap the top along the length of the bass bar, you will often hear a "clack" if the bar is loose. That's a pretty sure sign. But you can have a loose bar without the clack. Visual inspection is best.