I currently have 2 Alpine Type R 12's; Each running 2 ohms off a MRD-M500. I have 2 1F Caps, and a Lighting Audio battery They are in a Slot Ported Bandpass box. They sound AMAZING!! I make people think I have 18's all the time. I want to sell this stereo and go bigger. I dont wanna lose the SQ, but I want more bass. What should I replace this with? Im keeping the batteries and Caps. I need box, amps, subs. Might keep amps I really like them. I listen to 25-45Hz bass mostly. Any help would be appreciated. Oh yeah, im not rich either!