All of the sound clips/videos I've ever heard are when vehicles are on level ground. Try making one pulling a grade @2000 rpm @60mph. That's when the drone should be the worst.
It'll be awhile before I can do that, threw a rod a couple of weeks ago.
That said, I haven't noticed any significant drone even going uphill. I don't have any local roads I can do 60mph uphill though, but I get what you're after.
97 Thunderbird LX (The GT Bird)
PI Swapped NPI motor with some port work on the heads, PI cams, 80mm MAF, CAI that feeds from fenderwell. Jmod, 3.73:1 TL in Mark VIII carrier, Mark VIII aluminum LCAs, 93 Mark VIII driveshaft, PBR brakes (soon to be Cobras), 18x9 wheels, 255/40/ZR18 Tires, Front and Rear strut/shock bracing, GR-2 shocks, Eibach 1.5" springs, 1989 SC front and rear sway bars.