Bell repair = deadening sound?

[sirisobhakya]

Some of my underclassmen (who play much more frequently than I) mentioned this. I also noticed that a Bach 50B3 whose bell has been heavily hammered (it had creases and dents like the surface of the moon) sounds “more dead” (strong fundamental and sparse upper harmonics) than my YBL-830 and also a 50B that is in very bad shape but not yet repaired.

I get the theory behind it: work hardening and something along those lines that I learned in the first year of university. And everyone knows that denser material deadens the sound. But how much? It is very difficult to compare since every horn has its own sound from the start and the nature of the damage and repair can be vastly different. Have anyone done any in-depth research/experiment on this?

Long question short: if I have a visible (>3-4cm) on the bell, which one is better sound-wise; Repairing it or leaving it like that?

[mrdeacon]

Sometimes horns that have had rough past lives play like absolute garbage while other times they play better beat up then they did when they were brand new.

Personally I don't like have creases or large dents in my instruments and I get them fixed but I know some players who swear by their beat to hell instruments.

Usually when a bell plays reallllllly reallllly bad the bell has usually been thinned a lot by working out the dents, it's been over buffed or has had a bad lacquer job done. Those three things can mess up a bell pretty bad.

I know that's not very helpful haha but it's one of those things where you don't know if anything will change until you have the repair done. At that point you will either notice no change or you will notice a difference, whether it that be good or bad.

[Pre59]

And everyone knows that denser material deadens the sound.

That would depend on how far you want to project. I've always found that lightweight variants sound lively to the player but don't project as well.

[imsevimse]

I don't have much experience of before and after such heavy work, but I have a few memories of situations where bells were hurt and it had effect how the horn blows.

First time it was a King 3b that got hurt when I had it in a gigbag. The wire in the bell that helps to hold its shape must have snapped and the shape was not round anymore. That horn felt dead after. I took it to a repairman but he could not fix it.

The second problem was a Holton 180 that I bought on ebay. It had a sharp dent in the bell that I took out. It was a good horn when it arrived but was dead after I had worked on the dent. I had not used a hammer. All I had done was to use pressure with the round knife that is the right tool for these things. When took it apart again and put the bell on the floor I noticed it was not completely round. My work had made the shape oval. After I had fixed this the horn was back to good again.

I remember I worked a lot on a Edwards horn with a very thin bell that had hundreds of small dents in the bell from mutes. I must have made the bell thinner at least slight but I checked the horn before and after and there was no difference to notice.

I have never used a hammer on a bell. There has never been a need of that on any of my ebay horns. I managed to solve everything with the knife with the round blade that I've got.

To sum from my experience:
It seems small dents in the bell does not have any effect. Shape is important. If the bell is not round it effects how it blows a lot. If a bell has been worked so the metal gets thinner? I have no real experience on before and after but it is logical how thick the bell is effects how the horn blows. Better or worse? I don't think you can predict such thing. Don't use a hammer if you can avoid it, many bells can be shaped with very light pressure.

/Tom

[timothy42b]

And everyone knows that denser material deadens the sound. But how much?

Actually, no, we don't all agree on that.

I do agree with Tom's post on shape.

[doctortrombone]

If the bell no longer has any lacquer on it, you may want to try annealing it. I've done this with several bells that have been overworked, especially ones that had deep dents from slides rattling around in the case for years. You need to maintain some sort of heat sink on the bell rim so the solder doesn't ooze out. I've found that this improves sound quality on some horns.

Of course, it could also he unrelated to the bell. Maybe another repair wss botched. Check for air leaks and poorly-fitted joints. Best bet? Buy a cheap Chinese borescope and look it over from the inside.