TromboneChat

I just got my Edwards tenor slide back from Chuck Ward, and it works great...

Put the horn together, and used my Doug Elliott MB109/MB J/J8 with it, which I usually use with my Bach 50B.

Long and short: The horn doesn't sound flat in the upper partials, the horn sounds absolutely dead, like it's barely resonating.

I have experienced too-large mouthpieces making a horn very flat in the upper partials, but the partials are fine: instead, the sound up and down the horn is simply dull.

Mouthpiece, or horn?

Could be there is something down in the crook that is causing turbulence. Look inside with a small flashlight. Can't see anything? Run a snake through one side then look at the opposite side to see if something is visible. Nothing?
Is the water key cork sealing tightly? Is the water key not straight?

Longshot: your end bow (crook) could be leaking at the ferrules.

Hope something from this message is helpful.

It's the horn. Something obvious would have to be wrong with the mouthpiece for it to cause that kind of issue. Fill with water to test for leaks and loose parts and stuff stuck inside. Call Mr. Ward.

If I read it right that you have used MB J setup with tenor, then I think the mouthpiece is simply too big for tenor.

I feel it’s probably just a matter of the bass mouthpiece not being a good match for the horn. Tuning issues or lack of resonance would all be consistent with this. I’ve used tenor mouthpieces on tenor that were too deep and open and made the horn play dead. I’d at least test it with a tenor mouthpiece before blaming the horn.

Thanks, I don't know the horn well enough to know it's the cause, but since the horn is in tune with itself (excepting the usual partials) with this MP, the fact that it isn't exceptionally flat in the uper register is throwing me...

Try an appropriately-sized tenor trombone mouthpiece! Report back.

My limited experience: Screw-on rim and shank mouthpieces can sometimes feel “dead” to the player compared to a solid mpc. I don’t know whether the threads (or the space between the threads) contribute to that. It’s just something you get used to: it feels different, not bad.

Remember that what is heard in front of the bell (the audience) sounds very different than what you hear behind the bell. All things being equal, I think that mpcs with a screw mechanism tend to project a little more than solid-state ones.