I have the Akra slip but its coupled with a catless x-pipe. It has a "bassy drone" (not sure if it's drone or just base) also but at different RPM's...below 1,500 and also between 2,000 and 2,500. My base/drone is louder than yours and I'm also sensitive to the loud exhast noize but I like the extra power it provides so I just find myself up-shifting at around 4,000 RPM (at least
) so no bassy drone!!