I owned a pair of Infinity Kappa 6.5" 2 ways at one time. Some of the best speakers you can buy at your Circuit City, Good Guys, kind of stores. However they are power hungry and will sound best when hooked up to an amp. Deck power alone won't drive these speakers to the best of their ability.
While they are very good speakers (for the money) I have owned and heard some speakers that I liked more. It really all depends on what your budget is. And whatever you do, listen to any speakers you buy before you buy them. Your ears are the best judge of what you like. Bring your own music and turn off all the enhancements that the sales guys like to turn on and listen at varying levels. This is the only way to find our what speakers are going to work for you. Decide how much your willing to spend and show within that range.
My speakers Post Kappas:
Boston Acoustics 6.5" Rally series. VERY NICE. It's essentially a component system that mounts in the space of a 6.5" coaxial. They are very deep and I don't know if they would fit in the pro5. I had them in a '96 Nissan pickup and had to use spacers to get them far enough from where the window comes down.
I presently have an all JL Audio system. These speakers rock. I have 6.5" XR components in the front door, and 6.5" VR coaxials in the rear doors. Really sweet speakers and I love them.
