So you cut the rca's and wired them directly to your speakers? Thats interesting. I might not be correct but maybe someone could clarify; hooking the rca's straight to your rear speakers could more than likely damage ur amplifier. Also this might be the reason for the bad performance of ur "system". Get a line out converter.
Ok I will try to help.. The wires connected from the rear speakers going to the amp have an inside wire and a shield (PER SIDE) do you have the inside to the + and the outside to the - ?(it doesn't look like it is in the pictures)
If not that is what you need to do. Turn the gains down because if they are set to high you will kill the amp or the speakers or both. So the way this should be wired is. The rca middle wire to + the outside wire to the -, from there, the rca's plug into the "input" on the amp. set the crossover to LP from there wire the subs to the speaker connections on the amp.
*completely lost* but i would suggest cleaning up this mess by using a decent line out convertor...thats what i use in my car...it uses your rear speaker wires coming from your stock deck to create a signal for the subs..this is a much cleaner and simpler way to do this..Loc are cheap also i got my off ebay for like 20 bucks.. Good luck with the install
2005 Lincoln Ls
Front Stage- PG rsd Components 6.5's
Front Stage amp- Memphis mc-16-2004 Bridged 150x2
Rear fill - stock for now
Sub Stage- 15" Re Sx d4
Sub Amp - PA OV1-4000
Enclosure - RNC Enclosures Chambered Transmission Line tuned to 35 Hz
Wiring - Knuconcepts 1/0 Power/ground 10 gauge twisted speaker wire, Konfused Distro Block
Soon to come - Pioneer Avic D3
Refs: Is250, r/t pimp