Do a search under the Performance heading on this forum, and look for posts by Gerald or OkieScot (same person, just don't remember which name he goes by on this forum), he has a really nice true dual setup that has a nice low rumble. There are others as well, Gerald is the only one I can think of right off though! Also, there's feedback from others on other available after market systems as well. Many have pics and sound clips as well. As you look around, you'll find this forum to be a very useful resource! Good luck!
I have the true duals by Kinney's Muffler Shop in Bedford,Tx. StormTrooperDFW has the same set up that I have except I used a pair of 12" resonators in front of the
dual in dual out 22" Flo-Pro muffler. StormTrooperDFW ran his out the back and I ran mine out the side where the stock exhaust exits.
You can see my exhaust at www.picturetrail.com/okiescot. StormTrooperDFW has
sound clips of his truck and mine, but I don't think he has posted them yet.
Mine has a nice fairly deep mellow tone to it. It sort of sounds like a V-8 when you
are driving at mid-range rpms. It starts getting a little loud at 1900/2000 rpm. That is
73/74 mph and I seldom drive above that anyway. It still is not as loud and booming as the Flowmaster I had on my 2000 XE KC.
I was coming home from band practice tonight on the freeway and thought how nice
it sounds. It makes me want to keep driving.