I would not recomend this set up

They very well may be good quality amps and subs but they are not a good match for each other

PS

A gain control on an amplifier is an input sensitivity control designed to match your signal voltage input from your HU to your amp for optimal performance

it is not a volume control

There are definatly applications to over drive subwoofers but but to put 50% + more power to a subwoofer than it was designed to handle is suicide for that subwoofer