As others have posted on this forum, I found the stock speakers in my Vibe GT ( I went with the base CD/Radio and 4 speakers to allow me room to customize later) somewhat "muddy" sounding. I know the Matrix has 6 speakers including door pillar tweeters but my first test drive was in a Matrix and I was underwhelmed by the sound there also. However the Matrix does offer a Bazooka Tube subwoofer option that I got to listen to and was very impressed. Why the Pontiac gods in their infinite wisdom did not see fit to offer it with the Vibe is beyond me (especially given the current commecial featuring the DJ dude taking his tunes to work in his Vibe and rocking out with his honeys on his way in...go figure).Anyway, the Bazooka tube is not a concealed speaker. It installs prominently behind the rear seat looking for the world like some militia member's anti-ATF arsennal (no offense intended). Destroys the hauling capacity you say. Actually the one in the Matrix can be quickly detached and moved out of the way for hauling. I decided I wanted one of these.Luckily, the local Circuit City had a sale on the same size BZ tube. They also set it up to allow quick removal when necessary. Now this is a 200 watt unit so you could probably do some serious damage to your windows, not to mention your ear drums, if you turned it all the way up. Happily it also has its own gain control to allow customizing the sound (I have mine down between 1/4 and 1/3 gain. But this is the good part. Following the instructions for setting levels, I put the equalizer levels on "0", turned the sound up to just under distortion and then matched the BZ to it. I also set the Fader on the neutral setting. What I discovered was that leaving the Bass on "0" (which will still vibrate my rear view on certain songs) and bumping the Midrange and Treble up to around "3" I have a rather clear, clean sound in all registers. Even the audio guys were impressed. I still may do some speaker replacement to add some more vibrant highs but, so far, I am very pleased with the sound I have. So, before replacing all your speakers, you might try adding a subwoofer and turning down the stock ones. I think the muddiness comes from trying to make the rear set do double duty for bass and midrange. And for those who want to see my installation, I'll try to post a couple of pics this weekend. (I had thought of installing a remote rear gate opener and a rotating chamber for discharging a round of sufficient size through the tube to discourage tale-gaters from following two closely but abandoned the idea when my liability insurance proved to be prohibitive. )
[Modified by Vibester, 7:29 PM 9/26/2002]