I'm listening to the first one right now and playing with the variable tuning. In eq 1 (deep extension mode) and 1 port plugged it got so low the remaining port started chuffing! This is the first time I've felt the amps on the back of my subs any more than luke warm. They're not hot, but definitely warmer than usual. It's very deep (truly subsonic, what an experience!) and extended bass so I repeat, careful with the volume until you listen through this one.