exhaust q's

[rxm6]

Let me preface all of this by saying, I'm not going for loud and proud. More of a grumpy grumble. haha.

There is a large cylindrical object in the middle of my car that looks like a muffler. I think its called a resonator. What does this do for the sound of my car? Also, if I keep the stock muffler and upgrade every other part of the system, i.e. y-pipe, b-pipe, cat, etc. will my car still be as silent?