A really inexpensive option you might try is to get a Delrin cup extender for the Imperial. I love using one with my Imperial cup on my Eb. I feel like it adds just a bit of depth to the sound and makes it a bit more suitable for ensemble work. Ahh, thank you! -- I do have one of those extenders ...

Hi! I thought I would toss this out in case anyone had thoughts. I'm sure there are thoughts! :-D I have an Eastman Eb tuba (EBE853) that I love playing. I'm in the following mouthpiece situation: Sellmansberger Imperial w/ #2 rim : the most fun and easiest to play, but the stainless-steel resonance ...

I just thought I would weigh in (at the weight of an Eastman Eb) and say that the Sellmansberg II has become my go-to mouthpiece for ensemble playing on my Eastman Eb. I still prefer the Imperial for solo work, but the Sell II gives the EBE enough extra low-end oomph to really fill out the quintet ...