Where'd my bass go? Need help!

[CappsCity]

Before I installed my Pioneer DEH-P550MP HU, I had the factory cd player (non-monsoon sound system) and I had a line level converter to convert the rear speakers hi-level to a low-level input for my subs & amp I had in the trunk. With the gain turned up to 20%, I had some great bass (a little too much even). After I installed my head unit, I decided to run some Lightning Audio (LBIX-6) twisted pair RCA cables from the Subwoofer output (non-fading) from the Pioneer to the amp. Now with the non-fading output turned all the way up, the SLA on the HU turned all the way up and the gain on the amp turned all the way up, i BARELY get any bass. What's the deal? I knew Lightning audio wasn't the greatest brand, but can it be THAT BAD?! I mean I could cough and produce more bass than they're putting out now. Need help!

[grass]

heres what popped in my head

1) check your crossover points, if your amp is in 120 and up or so, then you'll barely get any bass

2) make sure you have your balance correct, not to the right, the right side has no bass in the tracks (or maybe the left, either way one of em has no bass)

[CappsCity]

i have the amp filters off for now so i'd be able to tell if it's working. One the head unit, all filters are off as well. so filtering is not an issue. I'm not sure what you mean by your second statement as i'm using the non-fading/subwoofer output.

[grass]

non fading is still affected by balance, i think, not sure, never had one :)

do you move your subs to a different box?

[CappsCity]

subs and amp are in the exact box/position as they were when i use the line level converter from the rear speakers signals.

[grass]

what kinda amp? sub? double check that you put the rca's in the back of the head unit in the non fading spot, i hooked my rca's to the front's on accident and took me forever to figure out what was wrong.

[embe]

Whenever this happens to me it's usually a crossover problem.

But, for some reason, I've found there is an audible difference setween high-low convertors and RCA input.

[MattBatt]

It sounds like a Phase problem check your speaker connections from the amp to the speakers. they should be +to+to+ and -to-to-
another way to tell is if you send the balance to one side or the other and the bass gets better.