I had the JF345 set on a Yamaha BB415 last year. the B sounded AWSOME! I first tried on it the DR Hi Beam 45-130, but the B was totally different from the other strings, and it lead me to think that the bass was not that good. I gave a try to the Thomastik, and BOOM, pure love. the B, even being a .136 had clear notes, balanced with the rest of the set, both in tension and feel, and even a dark sounding bass like the BB415 sounded clear and well defined.