my gain is usually turned up 1/4 and the sound is very loud, louder then the sub, and only starts when i turn up the volume to 45 out of 60. If i turn up the gain at 1/2 then it sounds like it bottoming out or popping at around volume 30. My head unit is the DEH-7300BT. The bass is set at 0 if thats what you were wondering.