the bass disappeared, preouts?

im using a Clarion DXZ775USB and it was connected to a pos 425w jensen amp (temporary, better stuff in order). well to avoid tearing everything apart waiting for new rear coax's i just ran a pair of 6x9's off one channel of the amp and 2 200w rms 12's off the other ( i know ittl destroy the speakers but they were on there way to the trash anyway). so today i went to power the new rear speakers from the head units amp and the subs from the sub out (RCA's were previously on the front because of the 6x9's) well there is next to no bass now... even with the gain cranked it wont get loud... reset the headunit and have all the x overs set right... even tried then set to through and still nothing... played a 50hz tone and put a multimeter to the amps outputs and got less than a volt AC the clarion is brand spankin new and i havent been grounding out the power or anything stupid like that.. could the preouts have gone bad? mind you there 6v if it helps ... if not what can i do to fix oh and i even tried using another amp... buddys brand new (i opened the box) sony xplod 1200w max version (the walmart one) and i couldnt get any sound from that.... pwr and grounds are all good.. good remote too and also i've gone from 0-max on the sub gain, regular sub volume (redundancy anyone) and all the internal HU settings... even gave it a hard reset a few time.... tomorro im trying new rca's and maybe trying a diffrent deck to see any other ideas.... i damned well hope i didnt fry some preouts... i never put them in a comprimising position

wouldnt let me edit my first post. if it is the preouts... can they be grounded like soo many pioneer have to be after a while

Are you using the subwoofer preamp outputs?  Are they turned on?  Where is the subwoofer level and Xover set in the HU?  How is the HU EQ set?  How is the Xover on your amp set?Support the12volt.com