Hi bruceg,
You'd connect the Carver's second set of speaker outs to the "high-level" (also known as "speaker level") inputs on the EP125. This should work fine so long as you can run the A & B speaker outputs on the Carver at the same time.
You could also connect the Carver main speaker outputs first to the EP125 and then to the main speakers. The EP125 simply extracts a low-level signal (for the subwoofer) from the speaker-level inputs and passes the main signals on to your main speakers. There is no degradation of the amplified signal from the Carver to your main speakers.
Regards,
Alan
Re
