I broke down and bought 4 Hogtunes speakers with the amp. Installed the rear speakers first and immediately noticed a HUGE improvement over stock. Then I changed out the fronts and played all 4 speakers without the amp hooked up. Sounded great, much better than stock. Then I wired in the amp....wow, did it add a great depth to the music, thumpin' bass and great tweets. I'm very impressed with the system. The instructions are so simple that even a cavemen could do it. IMO, well worth the $$.