dheflin44 Messages: 47 Registered: November 2012 Location: Carrollton, TX
Baron
Hi j0nny,
A lot of sub plate amps have high-level inputs as well as the normal low-level RCA inputs that connect to an AVR's pre-outs. To use the high-level inputs just connect them in parallel to the same speaker wires as the main L/R speakers. Note unlike an actual speaker, the high level amp inputs have a very high impedance so you don't have to worry about overloading your main speaker's amp.
This is not the ideal way to connect signals to your plate amps, but it beats buying a new receiver or ditching flanking subs all together.