Loud with throttle is right. I decided on the Thunderbikes after many hours of downloading sound clips and reading other posts. Also, Dinqua's write-up on them helped convince me. (By the way, I received them in Oklahoma just one week after ordering.) I like the deep tone at idle and the way they sort of let you sneek out of the neighborhood. Then cruisin down the insterstate at 60mph and could barely hear them over the wind, twisted the throttle and was up to 80mph in a blink (well maybe a couple blinks). They sounded like a V-8 on high octane. Love these pipes (so does the wife)!
