TromboneChat

I’m thinking about ordering another DE mouthpiece. Currently have an LT series piece for small bore. When I went to the website I noticed that the same sizes are also listed under MT series. What’s the difference?
Thanks!

Doug can probably explain a bit better, but the MT size has a smaller diameter cup.

I have a Giardinelli 5M and found it a little small for me, although I liked how it played in my alto. I was able to put my LT rim on, but there was a big step between the end of the rim and the start of the cup. I just got an MT rim (same size) and the step is much less. I suspect a ST rim would have a "reverse step".

Correct, the MT series is smaller at the point where the rim and cup meet.
The same rim number may be available in several different series. For example I make a 101 rim in ST, MT, LT, and XT (and EUPH too). They're all identical at the top surface and inner edge where you would measure the size, but all different farther in where they meet the cup.

So they all have a very different "feel" when playing. The smaller ones will feel tighter, and support high range more at the expense of low range.

Doug actually made me an ST104N rim... I want to say a year or so ago too. So I have an ST104N, XT104N, and Euph104N. In addition to what Doug mentioned, it feels to me like the closer I get to the ST side of things, the less flexibility I have both timbrally and in terms of the dexterity between partials. IE, when I'm on my Euph its easier for me to do lip slurs and I have more options to color but it takes perhaps a little more effort to play on the brighter side of things. When I'm on the ST, my default timbre is a little brighter (and perhaps more idiomatic for the things I use it for), I have a smaller overal timbral palatte of colors to choose from, and my flexibility is neither as quick nor easy as with the Euph or the XT series. However, notes, particularly in the high range, have much better landing spots. So the higher ranges are a little more centered and its easier to articulate/hit notes.

Those differences are also closely related to the relative depths of the associated cups, however.

The best use of something like an ST or MT N104 rim (or any large rim on an ST or MT cup) would be on alto or soprano trombone, or alto horn. Where you don't need low range.

Thanks for the explanations and improved perspective!
Jay