I tested my exhaust with a DB meter.. checked
it at idle and 1500rpm.. with just the Dynomax
muff it was 90db and 96db.. with the resonator
and the Dynomax(res was before the muff) it was
86db and 93db with a much better note
EDIT
all readings from 3' away at the back of the car
at work we did our noise readings from the side
of the car 3' away.. we did drive by test also..
at different rpm and a WOT reading for the drive
by