12 inch alpine type R. (300w at 4 ohms; 600w at 2 ohms) with keenwood 300w at 4 ohms. Or 500w at 2 ohms. This is my old stuff that I recycling back. Unfortunately my old Subwoofer is 2ohms per coil. So with this Amp I can only setting up at 4 ohms because the amp is not stable at 1 ohm.