Double Bass Wierd Sound Post Noise

[pmckee]

I just got back from school and pulled out the "lender" bass that has been sitting in my closet for the past four months. It sounded fine in April, but upon playing it last night this very noticable buzz was produced. It's an internal buzz, not a fingerboard buzz. I am 90% sure it is coming from the sound post. The problem only occurs when playing in the lower register. It is a really old carved bass so it has survived many years of abuse, but this is a new development in the time I've spent with it. I was wondering if anyone could give me some advice. I appreciate it. Thanks,
Pat

 

[accutone]

I am not a luthier and I am sure one will chime in, but I am speaking from the point of view of someone who has owned more than a few old, beat-up, sub $2,000 basses.(Even a few sub $500 basses back in the day. ) My home remedy was the following:

Just to be sure, make sure that there isn't a loose string end vibrating against something. (Its a long shot in your case, but I would check.) I don't know if you are in San Diego or Boston, but especially if you are in San Diego (dry this time of year as you know,) you might try putting a Dampit in the bass. It won't fix the buzz overnight, but one of my old basses used to dry out and develop a buzz and this helped. Check for newly opened cracks or an open seam also. (Take a very thin piece of steel and run it along the seams and see if you find an opening.) All that said, a buzz in an old bass can be hard to track down and you will probably have to go to a luthier. If he can locate the problem easily, he may be able to fix it without opening the bass. (If it is the soundpost, perhaps it has slipped as the bass has expanded or dried out, and he may be able to reset it, shim it, etc. and it should be worth the $) Of course, the soundpost transmits sound within the bass, so I would guess that a buzz may be heard there that originates somewhere else.

Finally, if the bass has to be opened to get to the root of the problem, the value of the instrument will dictate whether that is a worthwhile investment. In my experience with cheaper instruments, it often isn't.

Good luck.

 

[pmckee]

Hey thanks a lot. I am in San Diego right now, but it is pretty humid. I think I might weight this out and see if the buzz disappears by itself.

 

[Silversorcerer]

I think the buzz you are hearing may be the endpin and not the sound post. Sound posts generally do not buzz. If they are loose or poorly fit, they will fall over inside the bass, but I have never heard of a soundpost producing a buzz. A loose endpin is usually the first buzz that one hears in a bass. Try setting the endpin at a different lengthe and see if it disappears or moves to a different note. Next check all the seams and make sure there is no separation along the edges. An internal buzz if it is not the endpin could be a loose bass bar.

 

[wxfloyd]

I recently purchased a used Romanian ply bass that, upon inspection of a local luthier, had a buzz when really digging into it, especially on the lower notes. At first the luthier thought it was the bass bar coming unglued from the underside of the top. So he put it up on the bench, inserted a light, and couldn't find anything to prove it was a loose bass bar. For a moment he was baffled, but then remembered about the loose seems on the bass side bottom bout that he mentioned earlier. he pulled out a couple of clamps and clamped down the seems (two spots). He pulled it off the bench and dug into it again. No buzz!! turned out it was just the loose seems vibrating.

Long story short, if you can't figure out whats going on, take it to a shop and see if they can find out where the buzzing is coming from.