The attached image may also help a little. This is the Mustang track I used. Someone else's logic track may look completely different depending on what sounds they use. You could actually just throw in your old ENG file for each airplane and then adjust the volumes inside the Throttle tab as needed. This is where I've been testing different effects and there are still some bad examples shown (the Mustang Howl and Distance tracks are prime examples).
I used cockpit recordings for the Merlin Engine sound, added the Prop sound, and then what I call Merlin Song and the whistle track. In this view you can see the SpeedMPH fader that I added, but that's a bad idea. If you need to use Speed then you should add whatever sound it is to the wind sound, or use a referenced event. I ended up using the wind, and then in External sounds the whistle is added to the engine loop, but also controlled with an event cone angle. That way the whistle is only heard as the plane approaches much like the HTC Me-262 is now. In the external folder for the Mustang things are a little different and I will show that next. WEP is a track that should only take effect once the throttle is above 100%.
The whistle sound for the Mustang is generated by the machine guns and the duct, but the duct is heard primarily in diving attacks only. The machine gun whistles aid the pilot in landings and low speed flight, because you should only hear them as the plane slows down to land. That's not an easy thing to achieve in FMOD, but it can be done with a lot of experimentation. I worked it all out in the B-pony, but logging into the game and changing things and logging out and then back in got old. Hitech promised to have that fixed next update.
