We are preparing a very important update for CFM V2 soundpack, and it will be interesting only for NGXu users. Now the engine sounds will properly use built in sound engine in the NGXu.
That simply means - engine sounds will sound different on takeoff and for example on FL150, especially engine buzz. On FL350 you will not hear the engine whine/buzz at all, but you can still somewhat hear low frequencies (bass). Sounds really nice and much more realistic.
We completely overlooked this feature before the initial release, our apologies.
At the moment we have some problems building the installer, and as soon we find the proper solution, the update will be live and it will be followed by a demonstration video.