Ace24-
Coaxial means 2-way, there are also Triaxial, which means 3-ways, I havent heard what a 4-way would be called. But a 2-way speaker is what you asked about. A two way has a woofer for the lows and a mid-range tweet for the highs, sometimes adjustable, meaning you can move the tweeter to a different position for better sound. And a triaxial has a woofer, and two tweeters, for mid's and high's. If you didnt know about the 3-way's, you do now. So opt for them, Pioneer's are really good, especially the 4-way's which are even better than 3-ways. Sorry if I'am confusing you, so I'll stop now.
Brian