I have a Yamaha YCL-221(2)S Bass Clarinet and had been using the Yamaha 4C mouthpiece that came with it but was always unhappy with both the sound (regardless of reeds) and response, especially in the higher register, where I was always struggling to hit clear notes straight off. I thought the response was due to my technique and the sound (tone) was due to the fact that bass clarinet is plastic. The tone just always sounded like I was blowing down a plastic pipe. After some internet research as to what mouthpieces bass clarinet jazz players used, I bought the Vandoren B50 mouthpiece, and whoa! Immediate improvement in playability, it is much more free-blowing and the thing I am really impressed with is the actual tone. My tone no longer sounds 'plastic', you can really hear the reed and it sounds vastly better, it sounds vastly more natural and wooden, and no longer has that awful plastic tube tone. It has saved me a fortune because I really thought I would need to get a wooden bass clarinet to improve the tone. I had presumed that the plastic instrument itself was the issue. For that improvement alone I would thoroughly recommend this mouthpiece, but it is also vastly more free-blowing and I can jump between octaves much easier, trying to sound like Eric Dolphy. I use strength 3 reeds and it doesn't need loads of air pressure to get a full sound, which is something I was concerned about. I really am very pleased with it, it has transformed my tone and playing. Money very well spent. I use a leather strap style BG ligature, Vandoren 3 reeds and play Jazz. I also got a mouthpiece tooth protector, I use them on all my instruments. There was no gradual adjustment to this mouthpiece, the change was immediately noticeable and straight away I thought "yes, excellent, finally" and haven't used my Yamaha 4C since.