Mouthpiece Fit?

[harrisonreed]

There seems to be a lot of emphasis on the rim size/diameter, which is important. IMHO the cup depth, throat and backbore also play a considerable role when it comes to core sound, tone quality and range flexibility etc.
I'm currently switching back and forth between 3 bass pieces that have the same rim size/diameter, but different cups and throat/backbore specs.
Has anyone else made similar observations?

Yes, the main aspects of the mouthpiece, cup and shank, are so important. But you can't take advantage of it if the rim doesn't fit your face.

[Matt K]

Think of the rim size as a floor. It doesn’t matter what the bottom does if the rim doesn’t work for that size. So a 12C rim is basic at going to be awful on a Schilke 60 depth cup and there’s really no amount of tweaking that would make that work. Similarly, a 1.14” rim can only go so shallow before your lips are making contact with the cup. But once you get something that starts to make sense, the more sensitive you can be to the point where things like a change in shank taper are quite noticeable. I find for example the difference between an L8,L9,and L10 to be the difference if I just go down to a smaller cup too or stick with the L depending on what I’m playing. (I like a J/J8 for commercial and L/L10 for most everything else).

[boneberg]

There seems to be a lot of emphasis on the rim size/diameter, which is important. IMHO the cup depth, throat and backbore also play a considerable role when it comes to core sound, tone quality and range flexibility etc.
I'm currently switching back and forth between 3 bass pieces that have the same rim size/diameter, but different cups and throat/backbore specs.
Has anyone else made similar observations?

Yes, the main aspects of the mouthpiece, cup and shank, are so important. But you can't take advantage of it if the rim doesn't fit your face.

My assumption was that the rim does "fit your face" and has been found out often by "trial and error". Recently I have been amazed (positively), given the same rim size, what a difference a good combination of cup depth matched with throat/backbore could make.

[greenjambone]

I'll also mention that did the same as Harrison, trying to use a 6.5AL on small tenor for a long time. Doug solved that one for me.

Same for me! As soon as he put me on the XT 104 (103.5 on my .508 bore), my endurance improved and I don't have those drastic shifts. Haven't thought about going back to a smaller size.