Relax, I'm not suggesting mufflers don't cause drone. What I am saying is you are the only person in history that can hear drone from the stock mufflers. Hell, you can barely tell the engine is running with those on. If you detect drone from those ANY aftermarket muffler is going to upset you. Resos like I describe can hush this, though.
2014 Premium GT, SGM, Brembo, Auto, Tech, Comfort, etc. GT500s, Steeda UCA, VMP auto tune, 100 shot on BBR tune, best et: 11.38 at 120.85
2012 GT, Candy Red, Brembo, 3.73, Tech, Comfort, etc. Procal tune, Roush upper, UMI LCAs, Steeda red bracket, GT500s, 28X10X16 Hoosier slicks, best et: 11.91 at 115.23 RIP