Summary: I have the 400msx which is just a mono version of the 400sx. I have this wire up to 2 MA Audio subs wired for a 2 0hm load and crossed over @ 80hertz w/ 7-8 db of bass boost. This thing makes those subs pound harder then any amp I've had this these subs hooked up to. I'm using the stock headunit hooked up to the high inputs so I haven't found out it's true potential yet.
Summary: Just wired up my 800sx with three MTX thunder 6000's. What a bang!!!!!! Great amp pushing 600 watts to my three tens wired in parallel for a 4 ohm impedance. With the gain at 1/4 my Impala became a high powered vibrator. Great look, great price, and even better preformance.