for door speakers the cleanest i have ever heard/used are critical mass.they are pricey but the sound they produce are second to none.Focal,Hertz,Dynaudio,JBL,Polk Audio also make great sounding component sets as well.I have a roadster so I don't have as much trunk space so I made a box with 2 DC Audio 8 inch subwoofers(disconnected the puny subwoofers behind the seats)with a tuned aeroport on a Kicker 600 watt amp and it sounds good.Probably the smallest system I ever had lol;I'm used to my 20,000 watt stereo in my Dodge Ram lol