PontiacBonnevilleClub.com

I don't have drone with the same mufflers (just 2.5" vs. 2.25") and a Magnaflow resonator, on the Caddy and I don't have any drone on the Magnaflow's on my GTO. Got lots of other engine noises on that, but...

It can be a number of other things unrelated to the exhaust too, gearing, throttle position, load on the engine in whatever gear you're in, etc, etc... It was just in the 74 - 76mph window. Below that or above that, perfectly fine.

All I have is mufflers and new tips. What does the resonator do?
I tried recording the sound but it would not pick up the low dbs.
I'm going back to the muffle shop tomoro and I will see what they suggest.

If the tips are recessed enough behind the bumper cover it can cause drone. Any exhaust leak or exit that is 'under' the car will drone.

Just had my other exhaust tip installed most of the droning is gone this sounds way better.

A resonator, for all intent and purpose is basically another muffler. However, it goes about reducing noise not just by muffling sound like a muffler and it's chambers, directors, and sound deadening material. A resonator takes the sounds pulses/frequencies from the incoming exhaust air and creates alternate sound waves/frequencies to cancel out some of that initial pulse/frequency.