Mystery rattle, HELP!

[theweed42]

So, my wonderful flatback has developed a maddening rattle. It seems to be coming from somewhere in the lower back around bridge height, although I can never tell exactly where. It sounds like a blown speaker.

I've tried almost everything I can think of, including checking for open seams, changing strings, taking off my Realist, and adjusting the soundpost, bridge and tailpiece. Nothing helps.

Twice I have taken it to my luthier, who lives two hours away. But when I get there and unpack it, it refuses to buzz. Both times it's played completely fine. Then, when I get it home, the rattle starts back up in a day or two. Talk about maddening.

My luthier doesn't want to perform major surgery on it unless he can hear it buzzing. But I am at my wits end with this thing.

Does anyone know what could be causing the problem? Would a different shop be able to find the problem based on my description?

[MattyBass]

Maybe it is the endpin... : )
When mine isnt in my designated position it can rattle...

Best of luck

[JtheJazzMan]

Buzzing on a certain note or open string? Have you checked the bass bar? Have you had a good look around all the inside seams looking for glue drips?

[theweed42]

Matt: I tried adjusting that, no luck

J: I'll have to get a mirror to inspect it. It's not a brand new bass, though, so wouldn't glue drip buzz have shown up before now?

[JtheJazzMan]

Glue drips start to buzz when they separate from the wood leaving a flap that can vibrate against the wood, so theres no telling when it could happen.

[William Hoffman]

Originally Posted by JtheJazzMan

Buzzing on a certain note or open string?

?

[Eric Hochberg]

Since the buzzing stopped when you took the bass out of your area, maybe the humidity was higher there, the wood expanded and a crack (or bassbar, or brace) tightened up and stopped buzzing.

[tornadobass]

I had a mystery buzz on my 4 year old Romanian roundback. Two luthiers couldn't find the source.

Finally, when the humidity in my house settled in above 40% this spring, the buzz went away and hasn't come back. The humidity indoors has been in the 50% range all summer with the AC on.

I'm wondering what surprise I'll get by winter when the humidity goes back below 40%

[Jake deVilliers]

Originally Posted by Eric Hochberg

Since the buzzing stopped when you took the bass out of your area, maybe the humidity was higher there, the wood expanded and a crack (or bassbar, or brace) tightened up and stopped buzzing.

Yeah - or maybe the candy wrappers, dust bunnies or fingerboard shavings moved to a different spot when you transported the bass.

[moles]

Yeah, and I thought I was the only one with that crap inside my bass. In my Strunal, it's old paint-soaked masking tape.

Another thought (and I hope this isn't insulting to the OP) is that maybe it's something in the room -? It's happened to me before. A picture or light fixture starts buzzing, and you'd swear it was coming from the bass itself.

[BAJO]

I had that problem with a German Flat Back I had years ago The issue at the end was a loose back brace towards the corners and not the middle of the block.. That took weeks to find out after returning to my luthier with string changes and bridge height adjustments etc..... You'll find it) The weather doesn't help at all!!! Good luck

[theweed42]

Thank you guys for the help and advice. I decided to take it back to the shop where I bought it. They diagnosed the problem in 15 minutes - two popped back braces. Since it would have cost half the value of the bass to fix, they let me trade it in.

RIP old bass, you were a good first bass.

In exchange, I got a 2003 7/8 Paesold. It roars. Takes the edge off the grief, a little. Hopefully the climate is kinder to this one, as it's German.