I have been reading the mods for the s38 and the s26. Does anyone have any ideas for the N Center? I have one that does not keep up that well with my S38II mains. It has some reverberation that is audible at high volume. Would the polyfill clean that up? How much do you put in with a ported speaker? How about crossover mods? I would get the S Center if i could find one!!!