hey guys so i decided i would want to get a sound system and i consulted with a friend of mine who has a good system in his impala. He told me to get NEW infinity speakers/amp/subwoofers and tsunami cap. i was wondering if i do need to get new speakers because if i dont and have just stock speakers my subs would over power them

. any ideas? =\
OH YEAH! infinity or alpine ?
my set up would have been:
-6 new infinity speakers
-alpine subs 600w and amp 500w
-tsunami cap.