Going to reawaken this thread...
I have here for overhaul a modern Yamaha bass clarinet, and the pads have moderately aggressive resonators. The 18mm pads have 8mm resos, the 22 and 26mm pads have 14mm resonators. Some of both of these are 1-1.5mm Fromm the tone hole contact ring.
I'm curious whether these are stock? This is a relatively new model...YCL221-II. I was going to try the MusicMedic Roopads for bass and they are all plain and unpunched. As they are generally very tight, flat and hard (the Roopads), I don't really see a problem, as basses have played fine with plain pads forever, but am curious whether this is the way Yamaha supplies them.