I had this problem in an HSFX installation (Windows 7 64-bit)and never got it fixed so I deleted it and started with a clean install then installed HSFX.
This time (Windows 10 Professional 64-Bit) I am having the issue with one of my two VP MOD installations (I use one for playing on Hyperlobby with no mods added that didn't come with the mod pack and another installation with addional mods added).
On the version I use in Hyperlobby a problem developed a few sessions ago where the engine sound would quit (in a jet) after about 5 seconds when I looked straight ahead. If turned my head about 45° right or left the sound comes back until I look forward and 5 seconds later the sound went away. I have the same issue with a P-39 except the sound does not go completely away, just gets soft until I move my head.
This is from the log file:
Initializing DirectSound playback device...
[11:31:30 PM] Primary buffer created.
[11:31:30 PM] Playback format is set : sampling rate = 44100, num channels = 2.
[11:31:30 PM] Not enought hardware buffers (0), hardware disabled
[11:31:30 PM] Buffer caps : Transfer rate = 0, CPU overhead = 0.
[11:31:30 PM] Default speaker config is : 8.
[11:31:30 PM] Direct sound audio device initialized successfully :
[11:31:30 PM] DX Version : 7
[11:31:30 PM] Hardware - disabled [buffers : 0]
[11:31:30 PM] Extensions - enabled :
[11:31:30 PM] EAX ver. 1 [ ] - disabled
[11:31:30 PM] EAX ver. 2 [ ] - disabled
[11:31:30 PM] EAX ver. 3 [ ] - disabled
[11:31:30 PM] I3D ver. 2 [ ] - disabled
[11:31:30 PM] ZoomFX [ ] - disabled
[11:31:30 PM] MacroFX [ ] - disabled
[11:31:30 PM] SIMD render [X]
[11:31:30 PM] num channels 32
[11:31:30 PM] Cannot open audio file samples/infinite 1
[11:31:30 PM]
[11:31:38 PM]
I have changed the audio settings in the game ui to every conceivable configuration.
If I play the non-hyper lobby version there is no sound issue. It has the exact same configuration in the UI:
This is from its log file:
Initializing DirectSound playback device...
[11:55:05 PM] Primary buffer created.
[11:55:05 PM] Playback format is set : sampling rate = 44100, num channels = 2.
[11:55:05 PM] Not enought hardware buffers (0), hardware disabled
[11:55:05 PM] Buffer caps : Transfer rate = 0, CPU overhead = 0.
[11:55:05 PM] Default speaker config is : 8.
[11:55:05 PM] Direct sound audio device initialized successfully :
[11:55:05 PM] DX Version : 7
[11:55:05 PM] Hardware - disabled [buffers : 0]
[11:55:05 PM] Extensions - enabled :
[11:55:05 PM] EAX ver. 1 [ ] - disabled
[11:55:05 PM] EAX ver. 2 [ ] - disabled
[11:55:05 PM] EAX ver. 3 [ ] - disabled
[11:55:05 PM] I3D ver. 2 [ ] - disabled
[11:55:05 PM] ZoomFX [ ] - disabled
[11:55:05 PM] MacroFX [ ] - disabled
[11:55:05 PM] SIMD render [X]
[11:55:05 PM] num channels 32
[11:55:05 PM] Cannot open audio file samples/infinite 1
[11:55:05 PM]
I spoke with other players who had this happen to them and they never found a fix and like me the deleted the game and started over.
Any ideas of where to look for the problem would be helpful. Thank you.