I have some infinity kappas 5.25s. Used to have them in my truck. If you want quality, go top end like I did. If you just want bass, go toward something like pioneer or kenwood. The infinities sound real crisp with really nice highs if you have a good headunit (I had mine hooked up to a pioneer MP3 player). Sounded great. But didnt produce very much bass. I didnt have them hooked up to an amp though, and they probably would have sounded even better with another 30-50 watts of power.