Prochamber with Flowmaster Super 40's.... im not really liking it. The tone is great but it's REALLY REALLY quiet, i swear at normal cruising speeds I can't tell a difference from the stock H. At a take-off, revving or if you really get on it (especially if your driving by a wall) then its audible but even then it's pretty quiet. The tone is definately perfect though, but as far as volume this thing is a joke. Felt no power increase either. I'll probably leave it on for a while, maybe get another pipe later... maybe a UPR X which is what i was considering? Never heard an H in person. And now im actually wondering if the X-pipe is all that raspy like people say? B/C I was told by several that the PC was also somewhat raspy and made a lot of whoosing noises etc.... I don't hear anything, at really low RPM's it sounds pretty throaty but thats it.