i just bought a pair of memphis 15mc60's (6 1/2") and 15mc69's(6x9) coaxials, and installed them to a kicker kx350.4 (also just bought and they sound incredible. i am very impressed with every detail these speakers bring to the table. both pairs come with a HP/LP cross over and rotating tweeters--so they are a great alternitave to components if you want great sound and a lighter hit to your wallet. the midbass is strong yet firm, and the tweeters create a bright and crisp tone with every type of music i have played thus far--rock, rap, classical, ect. very good speakers and well wortch the money, i am delighted with my new set up.
by the way, the power ratings are 50watts rms for the 6 1/2" and 60watts rms for the 6x9s, thought i would add that because i had difficulty finding the specs.