Rocky,
You bring up a great point. Some of the "drone" is dictated by what has been done to the engine along with the exhaust system. I Bought a 06 Mustang with an after market exhaust system and traded it for 2 days later for another 06 with a factory exhaust. I don't like the "drone" sound. So maybe its more exhaust than engine? Don't know, just a poor boy trying to make a living!
Ken