I have a 900watt 4 channel amp that I have bridged to 2 kicker cvrs. The amp was given to me but a 2 channel amp would be fine for subs.

edit: Redz how many watts is your alpine?

 

these speakers max at 400 watt tho right?

 

the peak power handling on the 12'' cvrs is 800 watts.

 

That's the point, a two channel is fine, and honestly basically unnecessary. When you consider that sub sound is multidirectional and most of what you hear is reflected, stereo subwoofers dont make a lot of difference. The money is better spent on a better mono amp.

 

so how many watts would you deem neccessary for the 4 channel door and deck amp?