Uh Oh - Bell rim buzz - HELP!

[Mike-ICR]

With the holiday season here I've been recruited to play with a number of small groups. I dusted off my 3+1 EEb (the best choice for all the groups) and discovered a BUZZ! In rehearsal I thought it was something else in the room vibrating so I tested it at home and it was still buzzing. It only happens on open notes (Fundamental Eb and 2nd line Bb mostly).

I looked all over for broken solders and loose screws but found nothing. I tried touching different parts of the horn while playing and found nothing except for the upper part of the bell. The buzzing dampens (doesn't stop) when I touch the bell just above the leadpipe and it STOPS when I pinch or hold the rim.

I tried surgical tubing around the rim but the buzz didn't stop and it killed the resonance. What do I do?

[Mike-ICR]

A standard "French" rim bell (no kranz) very rarely causes a buzz. I would still suspect that SOMETHING ELSE on your tuba is buzzing. I'm SURE that you checked all of the valve caps... and with a 3+1 comp-style tuba, there are several solder joints where metal is simply laid together and soldered (with no formal "brace"). These are prime areas for solder joint failure.

I thought so too. I've never seen a standard rim buzz like this before. The leadpipe-to-bell and bell-to-top bow are the only spoon (soldered with no formal brace) connections. I inspected those and eliminated them at first but the bell-to-top bow connection isn't very visible. I only checked by trying to "wiggle" the bow away from the bell (and the touch test while playing). I'll take a closer look. Thank you.

DP- was your bell trouble with a plain rim or a wreath?

[Roger Lewis]

I have found a loose lyre screw to be the culprit on a number of occasions. Check it out just in case.

Roger

[Art Hovey]

I had a similar bell-rim buzz on a couple of old tubas. The rim of the bell is wrapped around a wire, which rattles on certain notes because it has somehow become loose.
(You have already found the location of the loose area.)
I solved the problem on both tubas with a pair of pliers by gripping the rim where it buzzes and bending it down slightly to tighten the brass on the wire.

To illustrate, imagine grasping a hammer or baseball bat with your right hand. The bat represents the wire, and your fingers represent the brass bell material that wraps around it. Now use your left hand to tighten the grip of your fingers by squeezing between the knuckles and fingertips. Do the same thing with the pliers to make the brass wrap more tightly around the wire.

If the horn is already a little bit beat-up the repair won't show. If the finish still looks good and you don't want to mess it up then protect it with a layer of denim.

[Mike-ICR]

I played it last night at rehearsal and tried a few things. First, I completely removed the lyre screw and 4th valve keeper (that flap that holds the 4th valve down like on the 3+1 euphs). That didn't help but I kept them off for the rest of the testing anyway. I re-checked all the solder joints and couldn't find a problem. I checked the rim for gaps or cracks and didn't find anything. Holding the rim while playing still works.

Today I plan to "flush" the bell rim (like LJV suggested). If that doesn't work I'll try the clothes pin method. That should help me pin point the problem and then I can try Art's idea.

Thanks, all. I'll report back with results!