Double Bass Need advice! small buzz... bass bar problem?

[clochard]

Greetings folks,
Here is my problem. Please read and react : I need advice

One morning my bass (Eberle ply) started emitting a buzz.
Description :

• The buzz is inside the bass, between the neck and low-E "shoulder".
• It only shows while playing the G, either open on the G string or on the D string.
• First chat with the luthier showed that the buzz is reduced if pressing the fingerboard upwards while playing.

Diagnosis (yet to be confirmed, will be on next meeting with luthier) : bass bar problem.

Things to consider :

• Strings have been changed without any effect on the matter. [edit]
• Weather conditions have been most harsh lately, "basswise", with a very hot and sticky / "moist" atmosphere (it's summer and I'm on the middle of the ocean).
• The luthier in my area has most likely not seen a bass for years, if ever.

Two approaches suggested by the luthier :

1. glue the buzzing thing without opening the poor bass ;
2. open it and fix it.

Both ways were not music to my ears... the first seeming like a "jobber solution", the second implying an operation for which I'm not sure he's equipped for, considering that this shop does mostly violins and guitars.

I'd like to hear from the community on things I should verify or try to troubleshoot this problem.

Many thanks to anyone that could try to shed some light on the matter.

--
Bass is an Eberle Ply bought less than two years ago, mounted with obligatos, a full circle pup installed on a tough bridge, the standard and replaned ebony fingerboard. If more info is needed, I'll gladly update this post with details.

 

[clochard]

Post re-written with more details and questions.
Thanks to anyone willing to give some advice, hints, etc..

Hugo

 

[El-Bob]

is you neck joint tight enough? maybe one of the screws is loose or stripped? something similar happened to my guitarists ibanez and when he changed his strings it fixed itself

 

[Bob Branstetter]

I think you have jumped to a conclusion without much evidence to go along with it. Loose bass bars are not as common as you might think. A buzz like you describe could come from most any loose seam/joint or even the endpin on the bass. Buzzes frequently sound like they are coming from places far away from the actual problem location.

Have you tried looking inside the bass with a light and a long handled inspection mirror? If you don't have a mirror that like that, they are available at most auto parts stores for under $10. You need to look at the ends of the bar since that is where they normally come loose. The lower bout end is by far the most common. If the bar appears loose at the lower bout end, strike the location on the outside of the top with your palm or hand. If the bar is loose, it will usually make a slapping sound when you hit it.

If you do actually have a loose bar, it can frequently be re-glued and clamped by loosening the seams of the lower (and possibly middle) bouts. Don't let anyone try to glue it by pouring in glue through the ff holes or without clamps. It absolutely has to be clamped as well as glued. If your violin/guitar luthier does not have the proper clamps for this job, find someone who does.

 

[clochard]

Well Bobs, thanks for the advice.

What worries me is that the "diagnosis" was made by the luthier, after seeing the bass, but without looking inside. The fella was suffering a severe hangover (he got up to see my bass in emergency on a gig day - long ackward story) and left it at that without taking it to the shop.

So indeed, some info is lacking. Will be hunting for it and will be posting as this story unfolds. Evidently, I hope it's something else...

Also : thanks for the much needed precision. I kinda needed to know how you magicians fix a bass bar. Glued and clamped. Got it.

 

[Bob Branstetter]

I would seriously question the opinion and qualifications of any luthier that would suggest a loose bass bar without bothering looking inside - hangover or otherwise.

 

[clochard]

Greetings Bob and fellow tbers ;

Update on the situation ;
second meeting with luthier revealed that the problem was *not* a loose bassbar - it's fine.
We ended up spending 2 hours refitting the bridge feet and nut, and the buzz is gone. Gone!

Explanation : (unsure and probably not accurate, but it's what I left that guy with) with age and weather conditions, the bass has moved and the previous setup wasn't so accurate anymore. A oh so slim unfitting of the bridge was causing the middle G (open G string and first G on the D string) to buzz in the bass's right-hand-side shoulder.

If the buzz comes back... I guess i'll then update this tread once more.

Thanks to M. Branstetter for the advice, which was most needed at the time.

Walk on...

 

[bonaventura]

Greetings Bob and fellow tbers ;

Update on the situation ;
second meeting with luthier revealed that the problem was *not* a loose bassbar - it's fine.
We ended up spending 2 hours refitting the bridge feet and nut, and the buzz is gone. Gone!

Explanation : (unsure and probably not accurate, but it's what I left that guy with) with age and weather conditions, the bass has moved and the previous setup wasn't so accurate anymore. A oh so slim unfitting of the bridge was causing the middle G (open G string and first G on the D string) to buzz in the bass's right-hand-side shoulder.

If the buzz comes back... I guess i'll then update this tread once more.

Thanks to M. Branstetter for the advice, which was most needed at the time.

Walk on...

I have been reading this thread with more than just interest because I have what seems like exactly the same thing.

From one day to the next (it has been fairly humid here, 65 to 70%, for months) my 14-year old carved Gruenert started emitting a faint but distinct buzzing sound.

Location: inside the bass in the middle of the upper right bout (E string side) but out away from the fingerboard.

This buzz is most noticable when I really dig in on open A or open G, sometimes on Bb on the A string.

It will stop when, while playing one of those notes, I press in on the top just next to where the bass bar runs. It will also stop when I hold the bass back firmly against my body or leg while playing.

I have listened many times over very carefully, and it is not coming from anywhere else.

Could this be a malfitting bridge, too?

What can I do about this, or what can a luthier do (short of open bass surgery)?

Thanks for any comments ...

 

[bonaventura]

just to tie up the loose end there...

I've corrected the problem I had (above) and it was also (like Clochard's problem) NOT the bass bar. And amazingly, like Clochard's solution, it was the foot of the bridge on the E string side.

There is a slight gap there between the foot and the bass top, and because I have a Realist inserted there, and some of the piezo foil was sticking out, well, it emitted this faint buzzing noise. The really odd thing was, the sound sounded like it was located in the upper bout. If anyone can explain how that happened, I'd be interested.

So anyway I took off the Realist and... it still buzzed, just not as loudly. I realized at this point that the gap (which had always been there) had been exaggerated by the fact that the bridge had moved out of center about 1/8 inch.

I re-centered the bridge and re-inserted the Realist so that the gap was no longer there. The buzz was gone. I played a gig last night with the bass and had no buzz.

Thanks to Bob Branstetter for responding to my frantic email.

 

[clochard]

Bonaventura : I'm glad my anxious posts hepled you solve the problem. So far, my (bad-)buzz is gone, and so is yours.

However, any further reader should keep in mind that it is very unlikely that the cause of such a buzz would be the "unfittedness" of the bridge - unless it has been moved significantly.

Nonetheless, it does seem rather sane to verify the accuracy of the whole basic set up of the bass (strings, bridge, nut) in the hunt for an annoying buzz.

I'm taking my bass to its original luthier (on "the continent") for a general set up, take 2. He will be able to tell me more about its evolution (2 fast years have passed) and potential problems, excluding bass bars and bridge feet. Will post updates if any other significant facts arises.

 

[bonaventura]

Clochard, yes, your follow up post was what really helped. If you hadn't taken the time to go back in and report on your solution to the problem, I would not have had the benefit of your experience.

I am going to replace the bridge at some point soon, and ordered a Despiau Superieur *** from Bob Gollihur. It was not only the gap in the foot that made me decide to replace it. It is also about 14 years old and starting to warp.

Bill