How to wire 2 amps with speaker level inputs?

Got a 4 channel arc audio 1200.6 running active fronts. Want to use my other amp for my subs. Before I got the arc I had a jl amp with an output I ran to the other amp. Hope I made that clear

 

Does your 4 channel have an RCA output? If so, you could run speaker level into the 4 channel and RCA’s out to the sub amp, otherwise you’ll need a line out converter with six channels of output to run four to the 4 channel and 2 more to the sub amp.

 

Thanks. Yes I think I got it figured out. I can use my rear inputs for the other amp and just set the 4 ch to 2 ch. Just talked with Mr Marv and he got me back on track

 

No worries, audio can be tricky sometimes.