Well, doppler effect depends on relative speeds [EDIT: when the speed of waves in medium is fixed]... If you want less doppler shift, reduce the speeds.
I would like to ask one thing though. Do the doppler shifts assume space as a medium for sound to travel in, or does it work using the player co-ordinates as a fixed reference frame and simply calculate them using relative velocities compared to player ship?
I mean, in an atmosphere there's a difference in doppler shifts based on whether you're moving through the medium in which sound traverses in, or whether the sound source is moving in the medium and you're stationary...
I'm assuming that the latter option is true, since the more complex way of calculating doppler ****s involves taking the speed of the observer relative to medium into account and, well, sounds in FS2_Open seem rather instantaneous anyway...
EDIT: Actually...
f = (c / (c + v)) f
_{0}...where c is the speed of sound, v is the relative velocity (positive for target moving away, negative for target moving towards), f is observed frequency and f
_{0} is the root frequency of the sound. This is the formula for calculating doppler effects for a listener who is stationary relative to the medium, which will work well enough for FS2_Open.
By changing the assumed speed of sound, it's fairly simple to change the overall doppler effect, so I retract my earlier statement and refine it a bit.
Special circumstances arise when relative velocity == wave motion velocity...
And, of course, this is an approximated formula. True solution of doppler shifts would possible cause sound effects to
play backwards[/b] when moving away from the sound source at mach 2. Though that would probably be a bit... complicated to implement in this sort of case.