Ok I got 2 Pioneer TS-A6991R 6x9's and 2 Pioneer TS-A4670R 4x6's and I will soon be getting 2 audiobahn subs (12's) and an amp for them, But my new pioneer speakers arnt producing that well, they distort easily and and have crappy bass. My friend said that they might lack bass because of Headunit which is a Kenwood MP4028. Do I need an amp to fix the distortion? Someone please help there good speakers and i know they can produce better. If i do need an amp could you recommend a good cheap one for all 4 speakers. thanks.