I got it narrowed down to 3 hifonics amps.-- z500d Zeus series puts out 500x1 @ 2 ohms. --z1000d Zeus series puts out 750x1 @ 2 ohms. --bx1000d Brutus series puts out 500x1 @ 2 ohms . All of these are class D mono amps. It is for an Alpine type-r 12" sub that is dual 4 ohm(500 watts rms) in a sealed box. It will be wired for 2 ohms.