i have the rca cables that work going to my rockfordfosgate amp which powers my 6X9s then i have 2 positive and 2 negative wires connected from that amp to my alpine amp for my subs... it works i was just wondering if anybody knew why the other rca cables didnt work cuz id rather have those hooked up to my amp than loose

 

bad rca's?

 

i dont think so ive tried 2 pairs

 

Your old amp, is it 2-channel just driving the rear speakers or 4-channel running the front and rear? The two outputs on your head unit, are they front and rear? When you say "2 outputs" I assume you are talking about two stereo pairs (4 RCA jacks), and not just 2 RCA jacks for left and right.

Make sure your new amp is set to accept input from the RCA cables. Disconnect the speaker level inputs. Then unplug an RCA that is driving your old amp and connect it to the new one. You should hear something; only the subs may be working so it will just be bass.

Once you have the sub amp accepting RCA level input, you can put a Y connector in the line of one of the RCA's to the old amp and the new one. Engage the low pass filter in the new amp and also the high pass filter in the old amp if it has one (the HPF prevents bass signals from going to the small amp and speakers. The sub handles all the bass and the other amp and speakers only the higher frequencies).

This is about the best you can do with the equipment you have. Ideally you'd replace the head unit with one that has a sub output (a total of 3 outputs). This gives you control of the sub level and frequency characteristics from the head unit.

 

its 2-channel powering just the 2 6X9s they are 2 steroe pair outputs. thanks for the help man