messing around with bore tapers without knowing anything

[bloke]

Someone traded me a few parts (several years ago) for a very distressed Yamaha YBL-322 (single rotor - copy of Conn 72H) bass trombone bell section.

Hopefully, both of us got the good end of the deal.

Since then, I've completely restored that bell section (just about perfect).

I had a c. 1960 (small) F. E. Olds bass trombone with a TUNE-ABLE duo-bore slide (.554" - .564").
It's very well-built, thus heavy (whereas most modern-day players might not care for it).
The slide (after taking it apart and truing everything) works very well, but (again) heavy.
I customized a King balancer (bass trombones typically don't feature balancers) to take the pressure off my middle finger (cheaper than buying one of those ergo-gadgets).

I HAVE the Olds bell section, but it's undersized (sorta King 5B-ish), the F-attachment bore is stuffy (only the same bore size as the bottom tube: .564"), and (tuned as sharp as it can possibly tune) it played HOPELESSLY below A=440, so the SLIDE was the perfect donor for this "cost no money" bass trombone (which sounds nice, and is pretty easy - WERE I ANY SORT OF PLAYER - to play in tune).

THE POINT OF THE POST:
Having the luxury of tuning BOTH the bell section AND the slide, I've found that - with the PLAYING slide tuned roughly 3/4 of an inch longer than originally intended, and the main slide on the bell pushed in most of the way - the IN-TUNE-NESS-WITH-ITSELF is optimized (centering around A=440), and (per typical, with a tuba that's easy to play in tune) the 3rd position C (1st valve) and 4th position B-natural (valves 1 and 2) tend somewhat flat...
...so its "happier" (as far as "the western tuning system vs. trombones" is concerned) with more capillary tubing and less expanding bugle.

Mrs. bloke says this instrument "sounds nice".
(I can't play it worth dog sh!t - trust me; she's listening to me playing overtone series - plural.)
I'm using a Schilke 59.
I can play it for a longer period of time (up to "high" B-flat) with a (slightly smaller) MiraFone (from long-long ago) bass trombone mouthpiece stamped ".562" (It's pretty similar to a Schilke 58.)

see...?? I wasted y'all's time ONCE AGAIN !!!

...or maybe not...(??)

[Bassboner]

The advantage of the TIS is to get the constant taper through the bell. I'm personally not a big fan of the Yamaha bones. Maybe you should give that Olds bell section a chance with the slide it was meant to be with. The 59 is a nice mouthpiece, but as a tuba player, you might be able to play something a little bigger to offset the bell dimensions. The Olds valve is a little funky, but it plays great, or at least mine did. Anyway, lots of people find the Yamahas inoffensive, and that's probably the best thing you can say about it.

I only performed one concert on that Olds bass - Holsts Perfect Fool. Not very frequently performed. Check that out some time. It starts out with bones. The bass bone and the tuba (and tympani, I suppose) lay down an alternate meter from the rest of the orchestra at about the 3 minute mark. In the recording below, the low brass didn't really lean on it as much as we did.

[bloke]

The particular model of Olds just sounded plain ol' "bad" as a bass trombone, and the Olds bass trombone (all put together) played about 25 cents flat with the slide tuned as short as it could be tuned. (ie. FAIL)
It's only a 9-in bell and the small end of the bell is not much larger than the size of a large bore tenor, so I might use the bell to replace one on a school owned large bore tenor that gets trashed.

You don't seem interested in my topic, which is the fact that - when I made the conical part of the instrument shorter and the cylindrical part longer - the tuning characteristics (how in tune the instrument is with itself, for use in western music) evened out.

The topic wasn't "I should have given that wretched Olds bass trombone a chance," but I guess it's okay if that's your topic.

Were it a 24 or a 22 Roberts, of course I wouldn't have tossed the bell section in the parts bin.
Rather than one of those remarkably fine models, it is either this model or a similar piece of restaurant wall decor:



Here's the brought back-from-the-dead YBL-322 (Yamaha copy of Conn 72H) bell section mated up to the duo bore Olds tunable playing slide:





Being that 72H is a real bass trombone, this copy of that model (yet with a duo bore slide) sounds like a bass trombone...
... and yeah, that's a drilled-out-to-fit-Yamaha King counterweight (that I added yesterday).
Like I said, the slide is pretty heavy and a single valve isn't quite enough counterweight for this playing slide. I could buy one of dozens of pieces of plastic sold on the internet to help support the instrument with my left hand, but - just for now - more weight on the back helps noticeably.

If I practice enough with this 59 mouthpiece, I might be able to play high B flats and C's for more than 15 minutes, but that's about all I can do for now. I really can't imagine myself being able to handle anything larger than a 59, yet (again) anything very much smaller starts not sounding like a bass trombone.

I really did a bang-up job saving the Yamaha bell section. If I had an hour or two to spare, I polish it and shoot some clear on it, and it would look like a million bucks. In the meantime, I think there are about 40 sousaphones here (along was other exquisite banged around pieces of brass) demanding my attention prior to the second full week of July.

... I have played some affordable bass trombones that play remarkably in tune with themselves (whereby the basic positions of the slide ask for very little favoring from one overtone to the next). One of them is the JP Rath 333 which I sell. I'm thinking my price when I sell those might still begin with a "2" (even after the hyperinflation we suffered a few years ago and the current tariffs), but I like what I spent for this Yamaha/Olds even more than my dealer cost of the JP333Rath. ... and I've played a lot worse out of tune (really expensive) bass trombones compared to this bass trombone that I stuck together that probably cost me a total of $1XX.

[York-aholic]

If I understand correctly (never a given), the inner and outer slide tubes for the bell section’s tuning slide are cylindrical. So there are always two cylindrical interruptions to the bell section’s conical/tapered profile.

So in essence your “frankenbone” (do NOT Google that) plays more in tune when you shorten those two cylindrical interruptions as much as possible (with the “missing” length made up for in the “tuning in slide” spot). Is that correct?

I am very trombone ignorant. I would assume that on a tbn that was designed for “tuning in slide”, there wouldn’t typically be any cylindrical inner/outer tubing on the back end of the bell. Is that true also?

I suppose I should become more knowledgeable about trombones but there really aren’t many spare brain cells left in my head.

[bloke]

Yeah, about the only other type of "trombone" that sometimes can be tuned in two different places is a valve trombone
- bell section
- the cylindrical bow at the far end of the so-called valve section.

Trumpets and trombones are sometimes incorrectly labeled "cylindrical brass" because they have long cylindrical sections vs. "conical brass" which have shorter and proportionally shorter cylindrical sections.
Of course, all brass instruments are conical, whether they are more or less so.
The tapered mouthpipe tube of a trumpet is apparent/easily visible. With trombones, it's hidden inside the first several inches of the top inside slide tube of the playing slide. Fancy schmancy trombones feature interchangeable mouthpipe tubes.

Just in case someone doesn't understand how a playing slide can be tunable, it's those two approximately four inch long tubing overparts. Rather than being soldered on solidly, they can slide back and forth with the hand brace, but be locked in place with a threaded rod and knurled nuts.