Modified Backbores vs. Non-Modified?

[ablazek]

I saw a comment on here from a respected mouthpiece maker a while that mentioned how a backbore that is modified to a larger size will have slight differences in shape and/or size from a backbore that has not been altered. This would make it more a hybrid backbore, rather than a true backbore in the desired style/size. Ex: a standard Bach C cup mouthpiece, which comes standard with #10 backbore, is enlarged by a 3rd party to a "24 size/shape" backbore.

Q: Would this new, modified backbore be significantly different from the 24 backbore that is standard with Bach A cups, or a custom C cup that had a 24 backbore from the beginning? Would other backbore alterations (117, 7-Schmidt, others) differ significantly as well, or not?

[delano]

Deleted by Moderators - obscenities are not permitted on the TH. This includes abbreviated and thinly disguised. Please refrain from violations.

[Norman]

[Jerry]

It depends upon who does the alteration.

[James Becker]

When we open a Bach #10 to a #24, our most requested backbore alteration, a very small portion near the exit does not get cut with our reamer. Other than that most of the #10 shape is altered, and we haven't had any complaints. Of course, if you're willing to wait for factory made to order mouthpieces we can certainly source them for you. With the majority of orders we receive for altered mouthpieces, we're able to process them on site in a day. The choice is yours.
_________________
James Becker
Brass Repair Specialist Since 1977
Osmun Music Inc.
77 Powdermill Road Rt.62
Acton, MA 01720
www.osmun.com

Our workshop is as close as your nearest UPS store https://www.ups.com/dropoff?loc=en_US

[jaysonr]

Osmun's #24 is fantastic.
_________________
Isaiah 40:8
3 John 2

[delano]

[trombahonker]

Hey Alec, hope you're well man!

I've got some thoughts for this. Specifically on your question, I think it's a pretty minute difference. You're more likely to experience variation between the modifications, even if done by the same person and tool. For instance, I have four Osmun-modified 1 1/4C mouthpieces with their 24 backbore. With a simple pencil test, it's clear that two of them are pretty dramatically larger in volume than the other two. Why? Who knows. They mostly play OK individually, but they all sound different. Actually, one is pretty terrible, but it was second hand, so who knows what's been tinkered with in it.

Something that may be worth thinking more about is the throat shape. This seems to be a place most mouthpiece modifications don't take enough into account. Is it just a straight reamer pushed in from the cup? Or was a jeweler's or taper pin reamer used, and again, from the backbore or cup? None of these are right or wrong, but for a specific mouthpiece/backbore/bore ratio, it can be critical. I've had the experience of asking for a conical throat and being stared at blankly like "uh...I use the 24 bit for that throat size..."

One of the "classic" mouthpiece makers once demonstrated to me how simply moving the location and shape of the throat, you can essential destroy or fix a mouthpiece, and then how you can tweak it to noticeably impact the resistance point. A Bach 1 1/4C with a straight-reamered 24th (this is how a lot of shops do this...) and a 24bb will probably be inconsistent and mediocre for most players. But opened with a taper pin reamer from the cup some (which moves the throat down the backbore), then brought closer to the cup by reaming some from the backbore...that will probably be pretty good.

That's a long way to say that it's likely you're experiencing the "what the heck, I have two 24th/24BBs from the same place...why are they both different????" It's probably the throat shape more than the backbore variation. This is why Parke and Stork mouthpieces play so damn well without modification - they've really thought about the throat shape in relation to the backbore and cup. Laskey too, although he's sort of defunct. Most other makers and modifiers don't seem to have placed as much importance on throat shape.

Best of luck!

[jaysonr]

[zaferis]

An interesting thread.. as many trumpeters I've gone through my share of tweaks and experimentation even with my current setup, that honestly I love.

This passed week I was leading a HS trumpet clinic with 40 students - naturally the conversations lead to mouthpieces. In doing this I noticed that I don't play on, nor stayed with, mouthpieces that I've had modified. Except for my C Trumpet. Bb, (commercial and legit), D, Eb, picc, Flugel, and Cornet (Bb and Eb) I use "stock" unmodified pieces.

I had the throat opened up for the mouhpiece I use on my Bach L-bore C-plays much better than the standard.

I'm thinking that opening the throat (just drilling to a larger size) changes the "balance" of the mouthpiece and if you don't then adjust the shape of the cup as it meets the throat and then the throat as it transitions to the backbore we're changing the piece more drastically than we think. Changing one little aspect has impact on others.

I have learned NOT to open up a mouthpiece I've been playing on, but to keep that one and order a new one with the modification that I'm interested in.

good luck
_________________
Freelance Performer/Educator
Adjunct Professor
Bach Trumpet Endorsing Artist
Retired Air Force Bandsman

[ablazek]