Even with just the muffler replaced, the 2 resonators under the car, by design, are muffling the exhaust note. When these resonators are replaced with one of a flow thru design(Magnaflow) or similar brand of your choice, the sound will be changed. IMO, its still a clean sound. No popping or sputtering of the exhaust note. To me, it deepens the tone. Check for videos on this where the resonators were replaced as well as the muffler.