First of all, I apologize for this rather lengthy post, however, like some of you, I have looked at this problem for some time, and if you bear with me for a moment I think I might have a few useful insights.
The sound issues in Flight Simulator X that I am specifically referring to here are the sound issues that resolve themselves when the Q key is pressed to momentarily turn the sound off and back on. These sound issues usually involve the engine sounds and occur after cycling through or changing the view, and also involve engine sound pitch and volume as the engines are running, or the plane is turning.
What is interesting to me about this sound issue is that it never occurred until I upgraded to a multicore processor machine. The sound issue never occurred on my older single core processor machine running windows XP. The issue has never occurred with Flight Simulator 2004, even on my new machine, which really puzzles me no end.
After upgrading to a Core 2 Duo processor with a P5Q SE2 Asus motherboard is when I began to experience the sound issue. I initially thought it was a problem with Windows 7, so I installed XP on the machine, and the same thing happened.
I set the affinity of Flight Simulator X to run on only one core of my processor, and the sound issue remained.
I installed and up-to-date sound card in the system, and the sound issue still was present.
Applying the Service Packs (SP1 & SP2) also have no effect. Changing the graphics options in the simulator also seem to have no effect. Updating my graphics driver (Radeon 4850 HD) had no effect.
Based on my own observations therefore, the sound issue in is independent of the operating system, and independent of the sound hardware being used.
I have also noticed that the sound issue occurs only with multiengine planes, and will also occur with some planes more so than others. For example, on my system, the sound issue is very prominent when flying the Grumman Goose and on a payware Lockheed Constellation (Just Flight -
www.justflight.com), but doesn't occur very much when flying the Beechcraft Baron or Air King (but it doesn't occur), and has almost never occurred with the PDMG 747-400. My conclusion from this observation is that the sound configuration files might have some impact on the frequency of the sound issue arising.
I also have tried to make numerous adjustments to the settings of my sound system, but none of these seem to have made any difference
I purchased the Flight Simulator Sound Studio available from Flight1(
www.flight1.com), in the hope that I might be able to use it and minimize the effects of the sound issues. The engine sounds for most planes are composed of at least four sound files. The sound files are each played back at various playback rates and cross-faded together as the throttle is moved up or down. Other filters are applied such as the sound cones and Doppler effects.
Interestingly, the engine sounds playback perfectly in Flight Simulator Sound Studio, if not better than in Flight Simulator X. My conclusion from this observation is that my sound hardware is obviously not the issue.
As far as I am concerned, the issue is clearly a bug in Flight Simulator X that is somehow related to the newer multicore processors. I am not absolutely sure of this, but it seems to make sense since more people have noticed it as the newer processors have come out. Flight Simulator X is obviously having a problem with the variable rate playback and real-time mixing of the engine sound files, or for that matter, selecting the correct sound files with machines that have the newer multicore processors.
Frankly, I don't think there is any fix to the issue unless Microsoft decides to support the program again and examine it. I don't believe that any hardware or software configuration settings alone are going to eliminate it, although I am hoping I might decrease the frequency and noticeability of the problem by editing the sound configuration files for the individual planes. Another solution might simply to be to stick with Flight Simulator 2004. Ultimately we may be stuck, for those of us experiencing it, with the sound issues until newer simulators come out. Cascade Game Foundry (
www.cascadegamefoundry.com) and Aerosoft (
www.aerosoft.com) both appear to be working on new flight simulators.
Anyway, for what it's worth, those are my thoughts and observations regarding the sound issues. If anyone else has anything to contribute on the topic, I would be eager to read what you know.