Ive been to a audio shop about upgrading the front speakers, focals £250 audison amp cost? carnt remember sound proof kit for doors £60 but they guy said i can keep the original HU? just run the speaker wire to the amp from the HU and then back to the speakers now ive never known that be done b4 ive always used phono leads, has anyone done this and is the sound quailty just as good thanks peps