When it comes to soprano mouthpieces, I can tell you that it is ALL about the chamber. Same exact facng and the same exact tip opening with the same exact reed on the same exact horn but with different mouthpiece chamber designs and you’ve got very different results.
So. let’s talk chambers, and let’s start simple. There are only two aspects to any mouthpiece: what is there and what is not there, meaning the physical solid mouthpiece and the invisible empty space inside the mouthpiece. When I speak about chambers in soprano mouthpieces, I’m speaking about the entire empty space. Now, you have heard terms like baffle and throat used in describing the inside of a mouthpiece. I try to avoid those terms most of the time unless I think they can be useful in a specific discussion. I don’t ever think about baffles or throats; I think about the single entity, the chamber. Why?
Because the precise shape of the chamber rules! A very little wider or shorter or higher or longer or lower in the mouthpiece and…..changes, big changes. I spend 95% of my time on defining and refining the precise chamber of a given mouthpiece because it rules the sound and, to a great degree, the response as well, especially for a particular horn.
In my soprano mouthpieces, here is the short of it on chamber:
ALMA : large chamber, wide, deep, sits lower
OPEN SKY 2 : medium chamber, moderately narrow, very deep, sits lower
MISSING LINK : medium chamber, moderately wide, moderately deep, sits central
AXIEME::medium small chamber, moderately narrow, less deep, sits central
METROPOLITAIN : medium / large chamber, moderately narrow, very deep, sits higher