what do you mean it only plays cds at volume 10? will it stop if you go to 9 or to 11?? depending on the head unit, it would be an idea to amp the speakers, althought not completely nessicary, most headunits make about 4x22 WRMS, 6" speakers run between 50 - 90RMS, 6x9s usually between 60 - 120RMS, so obviously, wou wont be getting the maximum out of the speakers