Adding a 4 channel amp?

I'm thinking of adding a 4 channel amp,<>.a href="http://www.sonicelectronix.com/item_1009_Visonik+V417SX.html>." rel="nofollow"http://www.sonicelectronix.com/item_1009…/a Right now I have a Nitro BMW-482 1000 watt amp <>a href="http://www.sonicelectronix.com/item_2640_Nitro+BMW-482.html>" rel="nofollow"http://www.sonicelectronix.com/item_2640…/a connected to 2 12" Kenwood subs <>a href="http://www.sonicelectronix.com/item_18045_Kenwood+KFC-W3012.html>" rel="nofollow"http://www.sonicelectronix.com/item_1804…/a with 400 watts rms each. My HU is just a cheap entry sony stereo and a great Equalizer, the Clarion EQS746 <>.a href="http://www.sonicelectronix.com/item_6655_Clarion+EQS746.html>." rel="nofollow"http://www.sonicelectronix.com/item_6655…/a Can I add the 4 channel amp to the car and just do the Big 3 and still have everything working fine?