As usual, Infinity Kappa are the best sounding car speakers I've ever owned. I decided to go for a cheaper Kenwood 3 way 5 years ago and decided it was time to upgrade sense my older 4 channel amp developed a problem with the RCA pre amp input jacks. I upgraded to a Kenwood Excelon XR400-4. Perfect match for these speakers. Absolutely amazing mids and highs at any volume, with no distortion. Definitely worth a little extra cash for the quality of sound these provide. Onlinecarstereo.com had the best price and service as well. Thank you!