1200w Amp good for 400rms sub?

what model # sony amp is it?

the guys were right before, most sony stereo amps are not stable to a 2 0hm mono load.  dont worry though, you have options.

for what i would assume to be around the same price you can find a sony xmd500x. this is a mono amp running 500 rms @ 2 ohm mono

or you could spend a little bit more and find a better performer such as jl, phoenix gold, etc...

i know it sounds funny but the load (subs) you show (hook up) the amp will greatly affect how it performs.

ill probaly go tomorrow then, what should i tell the guy? He doesnt speak fluent english it was hard to understand what he was saying but there were around 7 workers there who could speak fluent english. I dont know the difference between bad wiring and good. So I would rather go back to the shop I just dont know how to explain it to them to make them understand that it is not the proper amp for the sub.