You can get an rca adaptor that splits your rca's into 2 sets. I think you loose left and right channel tho.

 

sinceone, i am looking to buy those infinity speakers for my moms car. they have them on crutchfield, a more trusted site than ebay.

http://www.crutchfield.com/S-Hxazk16...sp?i=1086012SI

 

If your smart you can find them really cheap on a real website, then have sounddomain price match and get it from a reliable dealer with warrenty for really cheap.

 

I would suggest if you were to get a 4 channel amp i would spend the extra money and get a better LOC... Not to say that the Stinger isnt a good fix just for subs but if u want the max Voltage output from a LOC I would reccoment A David Navone Engineer LOC... here is his site.. and i have used them before... he is amazing... http://davidnavone.com/adaptor_products.htm look for the NE-774