i jus replaced all my speakers too, i went all jbl gto series, 6x9s and 4in. in the rear deck and a 5 1/4 components in the front, although i do have a jvc head unit. no amp and it sound great, bass, mid and highs. i have the same prob about the tweeter. i attempted to put in the 5.25's but my tweeter is bigger than the factory hole. so if you figure something out lemme no also thanks.