Muffler question

I was crawling around underneath to see how the 02 envoy xl are put together. I couldn't believe it when I saw TWO mufflers. The one on the tail pipe section a larger one in the middle, then the cat in front of it. Is that what I am seeing 2 mufflers?

Is there really a need for both mufflers? Which one would be better to remove on a exhaust change in the future? Never seen anything like that before. :screwy:

One is a resonator because of the additional lenght of the XL system, many vehicles are/were built like this. You could remove the resonator but the exhaust note may be louder.

Thanks Maxwedge, I am old school when it comes to vehicles and these new ones are throwing me curves left and right.

Here is a neat link describing how the resonator works. I had to know more.
Now if my old brain would remember how to shorten the links :disappoin .

http://www.google.com/url?q=http://auto.howstuffworks.com/muffler4.htm&sa=X&oi=revisions_result&resnum=6&ct=result&cd=1&cad=revid%3D396071384&usg=AFQjCNGMjlgM6UHOqw6gNxR-kmTGnENG9A