Nothing sweeter to me than PT6 turboprop engines screaming like banshee lightning, with the props well synchronized. Loud as a continuous bomb explosions on each wing.
PT^’s Blackdog? How about a couple of Garrets on an Aero Commander or a MU-2?
My personal favorites,
R-1690s, B-17
J-57s (eight of them on a B-52)
J-79s (on an F-4 Phantom)
J-58s (on the SR-71)
All distinctive sounds, best heard on takeoff from the flightline.
Me too...! Same engines... 100% 02 after lunch... Some of the best sleep I ever had. The hummm of a huey transmission and all the vibration was a close second.