The QS8s have an additional driver that the QS4s do not? Maybe I'm missing something but the Products page describe both the QS4 and the QS8 as dual tweeter, dual woofer designs...the QS4 has 2 1" tweeters and two 4" woofers while the QS8 has 2 1" tweeters and 2 5.25" woofers. Please, someone fill me in if I'm wrong here.