13w7 Distorting???

[fjolivo]

My system:
4runner
Pioneer avh 6050dvd Head unit
1 Polk Audio sr 6500 (getting the other pair probably)
2 JL Audio 13w7
1 Alpine pdx 1.1000 (hooked to 1 sub, getting another amp of this)
1 Apline pdx 4.150

The subwoofers sound pretty nice but... When I need it to be loud it produces some kind of weird noise (not in every song). Ive been researching and it is maybe because of the poor signal strenght... the head unit is pretty nice, it has 4v preamp, but the RCAs are 7meters long and ive been thinking that there must be the problem... If there is... What should I do? a buy a subwoofer processor? like the Soundstream Bx-20z? or the Powerbass Xba-2? or the kicker KQ30? all of them increase the preamp power (In case that it is what Im needing) I want SQ and some strong bass... If there is anything you know about how to improove the SQ, please let me know, my speakers signal might have the same problem even when they arent distorting much...

Thanks for the help...

[DSkip]

Set the gains properly like I mentioned in your other thread. I think thats the bulk of your problems right now.

[hc_416]

its the pdx. I have the exect same amp and it just won't run right. I bouth the pdx and to alpine type x ran off a alpine 9887. It just doesn't like to work. THe amp was shipped with the wrong fuse's check them first they should be 25's not 20. If you can get the pdx to work right it is great, but its very fickle and just not worth the time. hell i will sell you mine if you are instresed.