I'm looking for a circuit that I can build to make the sub an active unit, so I need power supply, amp and preamp diagrams, this won't be my first pcb build but I've never designed one and wouldnt know how to so any help would be greatly appreciated, the subs requirements are 600w rms 1200w peak and at 4 ohms, in the back of the plastic enclosure is a recess covered by a steel plate, the recess measures 200mm wide, 400mm tall and 85mm deep, so what I'd like to do is utilise this space for the amp, power supply and preamp. As its an injection moulded enclosure I assume that the manufacturer would have done this rather than have two moulds. Anyway any help would be much appreciated, and in return I will do this as a how to for other newbies, then everyone can learn from my mistakes along the way.