That doesn't however explain why the sounds are normal volume most of the time, then without any warning nearly double in volume. That is the bug in FSX's sound system.While reducing the volume of the xCJ11.wav and the xCJ12.wav files will mitigate the issue, it doesn't actually address the underlying problem with the sound system.Most of the time for me, simply cycling through the views will drop the sounds back to normal volume. Over the past many years of continuous development, I've racked up over 4,000 hours on the CJ1+... :(

I don't have the product in question but does the post I made earlier make any sense? Does it have any relation to the problem you guys are having? Are there any negative number in the sound.cfg?

I don't have the product in question but does the post I made earlier make any sense? Does it have any relation to the problem you guys are having? Are there any negative number in the sound.cfg?

Its not that there are negative entries in the sound cfg, the tip you have quoted takes assumption the fsx sound engine calculates volume at unspecified RPMs by extending the straight line of the graph plotted of rpm vs volume and considers only positive part of the value of resulting volume.I gave it a shot on aisounds by adding o,o as first entries of vaparms but it had no effect.Depending on the number of ai aircraft using same engine sound are active nothing helps and all related wav files play at full volume at the same time. The sound of ai aircraft which pulls to takeoff thrust on the runway becomes normal. If number of aircraft is less than 3 pressing Q to refresh sound mostly solves the ai sound issue. If number of aircraft is more than three pressing Q screws up sounds of all of them.The tip does not seem to have affect on user aircraft also. I experience the same issue on user aircraft with addon sounds which have 0,0 vparam entries to avoid -ve volume. Though pressing Q always helps on user aircrafts.At first I was excited but after testing the -ve volume appears to be a speculation and the sound problem seems to be an underlying bug in sound engine.

That doesn't however explain why the sounds are normal volume most of the time, then without any warning nearly double in volume. That is the bug in FSX's sound system.While reducing the volume of the xCJ11.wav and the xCJ12.wav files will mitigate the issue, it doesn't actually address the underlying problem with the sound system.Most of the time for me, simply cycling through the views will drop the sounds back to normal volume. Over the past many years of continuous development, I've racked up over 4,000 hours on the CJ1+...

I wasnt trying to explain why it happens, only what I did to stop it. I too have 1000's of hours in the CJ, including 5 'round the world' flights, and I got tired of having my ears ringing or hitting the Q key. Without those 2 files enabled, engine sounds are 'normal' now and I can actually hear the co-pilot talking :( However I have dozens of addon planes and the CJ is the only one that has ever had this issue for me.