I have had phoenix gold, pioneer, infinity and now polk audio. For me the phoenix gold had the best bass response, the pioneers were kinda bright and hollow sounding, and the infinity's would distort even with an amp. So far the polk audio (basic series) in the front and the polk momo's in the rear deck are the best sounding as far as mids and highs are concerned. The 6x9's lack midrange, but the 6 1/2's pick that up real quick. The highs are smooth and detailed and the voice really cuts through the 2 12's in the trunk. Perfect sounding system except my sound stage is kinda centered low in the vehicle. Do your research and get some time listening to the various brands out there. Just my .02!