I need some help identifying the source of a rattle

Inconnu · #1 08-08-2006, 05:50 AM

Hi !

I've bought my first upright 6 months ago and I have a rattle problem that I can't seem to identify. I'll explain the context of it, and I guess some of you might have suggestions... I'd appreciate it !

When I bought the bass (from a respected local luthier), I realised a few days later that the tailpiece wire was rattling. I brought it back to the shop and the luthier replaced it by a flexible steel cord (just as many on this forum or elsewhere recommand).

The rattle problem was solved when I played the bass at the shop but a few days later it was back when I played at home. Actually, it sounded more like a new type of rattle that would stop as soon as I put my finger on the top of the bass, near the f hole on the lower string's side.

I brought it back to the shop, the luthier spent quite alot of time investigating and thought he found the solution : the new tailwire was vibrating on the tailpiece so he put a piece of leather to cut out the vibration. Again, the rattle could not be heard when I played the bass in my luthier's shop but it came back a few days later at home.

The luthier is 100% sure it's a metallic rattle. I know that when I put my finger on the top of the bass, near the f hole on the lower string's side the rattle is attenuated... but as my luthier says, I happen to cut out the low frequencies when I do that, so it's logical that whatever is rattling stops to rattle !

I don't want to bring it back to my luthier's shop (since the problem seems to magically stop at his shop and comes back at my home). So I'm starting to investigate the problem myself. I know that they are no cracks or open seems on the bass. It's a few years old Strunal that looks almost new. The bridge does not sink down, the physical integrity of the instrument is 100% OK.

I was wondering, though, if the problem could be related to :
- Too much humidity in my home (it really isn't dry in here)
- End pin rattle
- It's a laminated top, maybe a piece of lamination starting to unglue ?
- Anything else ?

Could you give me tips on how to diagnose any of these possible problems ? Thanks !!!

nicklloyd · #2 08-09-2006, 11:07 PM

If you remove the endpin rod and screw, does it still buzz?

What notes cause it to buzz?

bribass · #3 08-09-2006, 11:59 PM

I've had mystery rattles that really sounded like they were emmenating from the bottom half of the bass that turned out to be from the nut. A string was sitting too close to the fingerboard, but the buzz didn't sound from there. It was amplified lower down on the instrument and sounded like it was comming from somewhere else. Check the nut.

BG

Inconnu · #4 08-11-2006, 06:21 AM

My luthier checked all fitting at my last visit and no buzz was audible at his shop... I doubled checked right now and everything seems right.

As for the endpin, it seems that the screw can be removed but there's some sort of stopper that doesn't allow me to remove the pin when it is at maximum extention. In that position, though, it doesn't seem to change anything regarding the rattle.

For the last days, the weather here is milder. It is much less humid and the rattle is gone. I'm starting to believe that it has something to do with excess of humidity. Is it a possibility ?

I'll try plugging it a dehumidifier in the music room when it'll get more humid to do the test.

Thanks for your help !

Kam · #5 08-11-2006, 08:59 AM

I had the exact same problem in my apartment during high humidity..it's gone now.

Bassist4Life · #6 08-11-2006, 09:14 AM

I have a feeling that it's the endpin too. Extend the endpin all the way, tighten the screw, and then play it.

What usually happens, it the excess enpin inside the body rattles. I am a public school orchestra director and a lot of instruments pass through my hands. 9 times out of 10, it's the endpin inside the body.

If you endpin doesn't come out all the way, I would get a new endpin. You can get a really decent endpin installed for around 100 bucks. It will have a nice thick brass collar and a srew on rubber tip. And, it shouldn't rattle.

Joe

Bassist4Life · #7 08-11-2006, 09:18 AM

I re-read your post and it seems that you already extended your endpin all the way.

Hmmm.

I've seen this happen a couple of times. Part of the F-hole was rattling against itself. One corner of the inside edge was barely touching the outside edge. It vibrated and rubbed together creating the rattle.

Joe

Doley50 · #8 08-13-2006, 10:47 AM

I had this happen once and it's kind of funny. I had a pair of tweezer
sitting on the desk were I practice and the vibration from the bass made
the tweezer vibrate. It sounded like a buzz.

Just a throught.

Inconnu · #9 08-14-2006, 09:24 PM

I played the bass in a few different rooms in my house, the buzz came from the bass. I guess it's really related to the excess of humidity we often have. It got dryer and cooler this week and the buzz is gone. I'll plug in my dehumidifier this fall and see if it works !