Ok i know that i might possibly get shot for asking this but i just can't quite get it straight. I have a old Keilwerth 1951, it's a big bore horn. So which mouthpiece type was supppose to be better for this?? Was it the big chamber or the smaller chamber?? Longer face or shorter? I've read conflicting info about this and i'm just confused. I now use a Selmer C* and it's fine, i have no intonation problems except way up high but that's probably just me. But there is a stuffiness in the D2 which i really don't like. So if i were to consider another mp am i looking for a Large chamber or a small chamber for this horn??