I have a question on some speakers for the EMX512SC. Can I use two Kustom KCP215H speakers as mains? Running 2 of these on the "main" channel. They are rated at 4 ohms. Buy Kustom KPC215H 2X15 PA Cabinet Pair | Unpowered Cabinets | Musician's Friend Thanks. I'm not sure about the ohm/output.