Hey guys i only have 2 sets of RCA outs from my head unit, is it possible to hook up a 4 channel amp as well as a mono block amp and have all the speakers (Front L&R, Rear L&R, Sub) being powered off the amp? At the moment i only have RCA's going to the mono block amp which is obviously powering the sub.

Also how do i connect a 2 amp system up? I can only seem to get one amp to work at a time.

Would have been better to start this thread in the Audio section, better responses. Maybe a nice kind Moderator will move it for you.

What you are going to do is get some RCA Splitters ($5-$10) for a cheap one and you will need two of these, then hook one splitter onto the L input side of the RCA and take one of the now split ends into each amp (one into the L, Rear Channel on the 4 Channel amp and the other on the L Input on the mono block)

Repeat the process for the R side of the 4 Channel and Mono Block.

Also depending on the amp, when i say L, or R, i am referring to the Left and Right Channels which may just be identified by the colors be it red or white !

You don't necessarily need splitters depending on the amplifier. If your amplifiers have output RCAs, then you can just buy an extra set of RCA cables and run the cables from the output RCAs into the input of the other amplifier...

On my old head unit, I only had 2 sets of RCAs but had a mono block and a 4 channel amp. I had to run the 2 sets of RCAs into the 4 channel amp and another set of RCAs running from my 4 channel amp RCA outs into the mono block. Worked like a charm.

But if you don't have the option of running RCAs from one amp to the other...splitters will suffice as peaandham suggested.

I have Kicker amps (X350.4 and X750.1), i think splitting them may be the best option for me.