Dual 4 Ohm Sub Wiring Help

I have the jbl system in my '13 DC. I've installed new speakers and a P3SD4-8 sub. Wanting a little more volume out of the system, I've added a lc7i and a

$400 rockford R600x5 prime 5-channel amplifier

rockford R600x5 amp. Wiring the speakers to the lc7i and the amp was no bigge. They sound great with the added wattage.

My question is: The R600x5 runs the sub in parallel. The stock harness has 4 wires to the sub as the stock sub was a DVC. When wiring the lc7i, I need to connect - to - and + to + on the sub. This would give me 2 ohm. But how is the wiring from the sub hooked up. Should I take from stock harness the + from 1 coil (1st pair of wires) and the - from the other coil (2nd pair of wires) and run them to the lc7i on channel 3. Hooking up only + and - on the left and right?

Thanks.

 

The LCi7 will split the incoming signals for a separate bass rca for your amp. I connected only the front and rear speakers into my LCi7, then ran 3 sets of RCA's to the amp. If you already have everything hooked up, just run a set of RCA's from the channel 3 to your amp's sub channel.