What part of the Mouthpiece most greatly affects focus?

[MountVernon]

I'm curious if I want to make my mouthpiece more open, without the sound spreading, is it the throat that I want to keep the same?

[Andy Cooper]

If you are using Frost threaded backbores and have a #28 throat at this time, then order the #27 throat in the same backbore. Do not have your present #28 modified.

[MountVernon]

how do you know it's not my throat that needs to be the same, and the backbore opened?

[Andy Cooper]

[stuartissimo]

[MountVernon]

Focused sound as in, no air in the sound, very pure.

[Brassnose]

I play AR resonance with a 40 (i.e. 4 mm) throat and have basically played all backbores from 40XS to 40L and 40L Classical. The XS provides a very focused and dense sound and I sometimes tend to overshoot notes. The larger the backbores get, the broader the sound gets.

I pretty much agree with stuartissimo in that the density of sound (and the slotting to some extent) are affected but the XS backbore is by no means tight. It still blows quite open.
_________________
2019 Martin Schmidt eXcellence
1992 Bach 43GH/43
1989 Kühnl & Hoyer Model 15 flugel
1980/2023 Custom Blessing Scholastic C 😎
1977 Conn 6B
1951 Buescher 400 Lightweight
AR Resonance, Frate, Klier

[MountVernon]

So, am I looking to open the throat or the backbore?

[JayKosta]

[Andy Cooper]

Knowing what mouthpiece you actually play would be a big help. In looking over your past posts it would seem that you are using a Frost 5 or 6 TF - trumpet flugelhorn mouthpiece. It might be the TC model, but since you said the cup was like a Bach 5V - the TF would be closer.

Here is the Curry TF in 3C size compared to a Bach 5V. The Frost is probably similar

https://trumpet.cloud/mpc/index.html?mpc1id=VA4580002&mpc2id=VB005700&backcolor=blue

It should be marked on the mouthpiece - something like 5TF or 6TF.

The Frost TF would have a proprietary backbore matched up with a throat size appropriate to the cup. (I don't see how he managed to get a Flugel cup to play with a #28 throat.)

The Backbore is shorter since with a cup that deep, the horn would play flat with a standard length backbore.

If this is the mouthpiece, it was designed to play the way it does. You would need to contact Frost to modify it but it would be hard to say what it would play like after modification.

If you want a different sound why not try something like a Bach 6. Nice medium dark, focused sound with a lot of core. You can bore the throats out on a Bach with out doing much damage. It would also not be a big deal to have one cut and threaded for backbores.

[ek1986]

In my experience, keeping the backbore the same but opening the throat will only provide more core to the sound. If this same route is overdone, intonation (and stamina) will suffer.

EK