Okay I did a "search" and didn't find any answers to my question.

So here it is. I am looking at upgrading to a 4" exhaust and am comparing the Banks and MBRP systems(downpipe back). My main concern is the loudness(drone) of the muffler in the cab. I had a Kennedy system with the short muffler on my '95 TD and the drone in the cab was awful, don't want that again. I have an '02 CC/LB with a canopy and was told that the canopy can make the sound louder than without.

Thanks