My friend just bought these for his car, Amazon.com: Infinity 609CS 270W (Peak) 6-1/2 x 6-3/4 Two-Way Component System Speakers (Pair): Electronics .. he wants me to install them. Should any cheap 2 channel amp be fine to power these? He only has front speakers and tweeters in his car, nothing in the rear. Also, I don't believe he plans on doing a sub, if he does.. he's just going to get a new amp then.