First, is the L7 a dual 4 or dual 2 ohm voice coil? The 12 inch L7 is 750 watts rms so any amp that puts out around that many watts at the right ohm load would be fine. It primarily depends on how much you are willing to spend. Having an L7 must mean that your willing to spend some money. Having that said, please don't waist your money on junk amps such as Sony, Pyramid, and Pyle. Suck it up and dish out some cash on a quality amp. Once you tell me what ohm your L7 is I will further help you on deciding on an amp.