So I'm having a problem with my subs. 3 10s in a box, one input, probably wired in parallel. I run them on a 2 channel kenwood amp. If I run them only on channel 1, their just fine even at full volume. If I run them bridged (positive on channel 1 positive, negative on channel 2 negative) then they work just fine for low volume but when you crank em, rather than clean bass they make random vibrations, almost like their all hitting at different times instead of at the same time. Any advice? they are single voice coil 4 ohm MTX Blue Thunders if that matters. I'd really like to get them working when bridged, more power, and much louder!