My outlaw LFM2 sub makes a loud pop or boom when the power is turned on or off on the reciever, when you manualy change tracks on a cd, when you change chapters manually on dvd's or change menues or when the previews change, and when certain light switches are turned on or off. What could cause this??? The system, Denon AVR 5700 connected via line level output, a Y cable splits the signal to each sub. I am using a Monster power bar to connect everything. I have tried: just one sub with Y, both subs, Shack audio isolator (this just added a hum to the system). Nothing seems to work, and then I used the high level (speaker cable to sub then out to speakers) and this eliminated the pop. However it seemed that the subs did not put out as much sound as when hooked up to the LL on the reciever? And I don't like the dubble run of speaker cable. So, is it the recievers LL out??? Or is it some type of ground loop or earth loop in the houses electrical wiring? And if it is what can be done. I am thinking of trying the Jensen Sub 1RR, any thoughts??