In my xj i run infinity all around, componenets up front, with the tweeter drilled just above the speaker, sounds amazing. Power them off my pioneer 7700 mp, works fine until i buy a 4 channel amp for them. (also has ipod ability which is amazing) for my subs i have two jl 10's and a memphis audio m class monoblock amp. Sounds amazing and is really well balanced for everyday use. If your looking for cheap, i just picked up an MTX 420 watt monoblock amp and two inifity 12's off of crutchfield.com for like 280 bucks, sounds great and is really loud.....