I have a portable dvd player that has audio left and right outputs. Could i hook up my rca cables from my amp to those outputs on the dvd player and have it work? I was thinkin that i could turn the volume to zero on my H.U. (so power is going through remote turn on wire). Then i would be able to adjust the volume of the subs with my dvd player right?

ok if you just want to hook it up to your subs then i'm guessing the dvd player has its own speakers built into it. so yes you could hook it up that way but no will not be able to control the volume of the sub with the dvd player. it probably won't sound to great with the dvd speakers and the sub anyway. you would be better off hooking it to an aux on your deck if you have one. which i'm guessing you don't if you want to hook it up that way.