This thing sounds crazy. I'm not into loud stuff, but man I like this. It is loud, but I'm gonna go with it. I like to crack the throttle and just make it fire hard once. This thing sounds like a SHOTGUN going off. BOOM, BOOM, BOOM. It's not high pitched like a backfire, but almost as loud! This thumper sounds cool with the HMF. I will probably quiet it down with a TEC, to save the riding areas, but it's fun to snap it real quick for now!!!