Having approx. 80 flight hours as flight engineer in Ka-32 (featuring the same engines and similar rotor system as Ka-50) and quiet a lot in ground runs both from inside (cockpit) and outside I can tell you that the original sound of Ka-50 is VERY, VERY realisitc in all modes- idle, auto, take-off power, maneuvering, high speed, high rotor RPM, autorotation, spool down.
I don't want to discourage you, I respect your efforts, but IMO it's a waste of time to try changing something that doesn't need a change.