Jim (Broadstone), how have you been connecting the sub to the Behringer? If by any chance you have been using an XLR-to-RCA adapter or adapter cable at an output of the Behringer, most such adapters short the inverted signal on XLR pin 3 to ground (XLR pin 1). The output circuits of some components will not be happy under that condition, and damage could conceivably even result in some cases. (There is no problem using such an adapter at XLR inputs, as you indicated you are doing).
Regarding the possibility of connecting the sub to amplifier outputs, assuming the sub can accept speaker-level inputs, your amp is class D, and apparently uses some version of the ICEPower class D modules. Some ICEPower versions have large DC voltages on both their + and - output terminals. I would therefore not connect a powered sub to the outputs of your amp without first getting an ok from Peachtree. Or if Peachtree indicates that the 220 has that kind of an output, using specialized adapters that have been available which utilize capacitors to block the DC.
Best regards,
-- Al
Regarding the possibility of connecting the sub to amplifier outputs, assuming the sub can accept speaker-level inputs, your amp is class D, and apparently uses some version of the ICEPower class D modules. Some ICEPower versions have large DC voltages on both their + and - output terminals. I would therefore not connect a powered sub to the outputs of your amp without first getting an ok from Peachtree. Or if Peachtree indicates that the 220 has that kind of an output, using specialized adapters that have been available which utilize capacitors to block the DC.
Best regards,
-- Al