Just a question, couldn't this happen in real life anyway with multiple engine aircraft, after all the engines would all have the same sound but they may well be slightly out of phase causing the same effect.Just a thought.CheersMartin

Hi again:As this thread might stimulate some increased interest among the FS Community for tinkering with aircraft sound sets, I thought a few other threads with some related info on the subject might be worth mentioning here. :( At the time I posted to the following threads, I did not address the issue of "Forward" versus "Reverse" attributes in *.WAV files, but I did mention the potentially significant consideration of methods to resample *.WAV files with less loss of audio quality.Additionally, I questioned whether FS "Stereo" versus "Mono" FS aircraft *.WAV file formats might be best to use with what, AFAIK, is now DirectX DirectSound 3D audio processing in FSX.Regarding FSX "positional" sound, I also shared some ideas for implementing FSX "sound cones"Some links to those threads follow... I'd be curious as to what insights others have on these ideas related to aircraft sound set creation / conversion, so please post back here ! :( http://forum.aerosoft.com/index.php?/topic/26346-ascdll-and-surround-51/page__p__164151#entry164151http://www.fsdeveloper.com/forum/showthread.php?t=15956Additionally, I suggested that one might be able to improve AI aircraft sounds with some experimentation: :( http://forum.simflight.com/topic/44824-fsx-sounds/BTW: Subsequent to the latter discussion, Alan Constable implemented some nicely enhanced FS AI sounds with his add-on here:http://secure.simmarket.com/a-constable-traffic-sounds-fsx-extreme-edition-2009.phtmlFYI: < I have no connection to that project, but was glad to see the results of his inquiries were successful >I hope these links might promote further exploration and discovery with both legacy and FSX aircraft sound sets. PS: Anyone able to make a sound utility even better than Aerosoft's "asc.dll"...for both freeware and payware aircraft ? Consider using Doug Dawson's 'gauge kits' for FS9 and FSX:http://library.avsim.net/esearch.php?CatID=fs2004gau&DLID=95460http://library.avsim.net/esearch.php?CatID=fsxgau&DLID=158634http://library.avsim.net/esearch.php?CatID=fsxgau&DLID=158611Happy Tinkering ! :smile:GaryGB

Just a question, couldn't this happen in real life anyway with multiple engine aircraft, after all the engines would all have the same sound but they may well be slightly out of phase causing the same effect.Just a thought.CheersMartin

Hi Martin,It's true that real engines do slightly phase together, but because of slight differences in sound due to position, vibration, ambience and other factors, they do not phase quite so artificially as when similar or same wave files are repeated in FSX. As you will know, twin or multiple engines are "synced" either manually or automatically to eliminate annoying surges or oscillations due to them being nearly the same rpm. As with a piano note that is made up of two or more strings, or tuning one note relative to another, "beats" can be heard which represent the slight difference in frequency ratio.Even where real world engines are syncronised, there is an ever so slight difference in pitch and this sets up a very slow oscillation (the type you can hear at night when a twin engine flies overhead and you hear a slow frequency "drone" sound which is the small difference in rpm between the two engines).In an artifical simulated scenario the phasing effect is much more annoying because the wave sounds are so similar and are not affected by other influences like ambience, distance between the engines, or different sound qualities caused by variations in the stroke of the engine parts, exhaust sound and other factors.By the way, when using FSX's sound cone system to place wave files like engines and wind effects in a stereo field, all the wave files using the outside cone have to be in mono. If they are already stereo sounds FSX fails to place them in the desired position.Rob - RealAir

Just a question, couldn't this happen in real life anyway with multiple engine aircraft, after all the engines would all have the same sound but they may well be slightly out of phase causing the same effect.Just a thought.CheersMartin

Indeed and sometimes you can actually hear the two engines phasing as they are not 100 pct in sync if you are close to them in the passenger cabin.However, from the inside it sounds quite different from the phasing sound you get in FSX (which sounds more like exterior fly by kind of thing).And in the cockpit it would probably hardly be noticable.So in my case I would rather be without it.Soren

Hi Martin,It's true that real engines do slightly phase together, but because of slight differences in sound due to position, vibration, ambience and other factors, they do not phase quite so artificially as when similar or same wave files are repeated in FSX. As you will know, twin or multiple engines are "synced" either manually or automatically to eliminate annoying surges or oscillations due to them being nearly the same rpm. As with a piano note that is made up of two or more strings, or tuning one note relative to another, "beats" can be heard which represent the slight difference in frequency ratio.Even where real world engines are syncronised, there is an ever so slight difference in pitch and this sets up a very slow oscillation (the type you can hear at night when a twin engine flies overhead and you hear a slow frequency "drone" sound which is the small difference in rpm between the two engines).In an artifical simulated scenario the phasing effect is much more annoying because the wave sounds are so similar and are not affected by other influences like ambience, distance between the engines, or different sound qualities caused by variations in the stroke of the engine parts, exhaust sound and other factors.By the way, when using FSX's sound cone system to place wave files like engines and wind effects in a stereo field, all the wave files using the outside cone have to be in mono. If they are already stereo sounds FSX fails to place them in the desired position.Rob - RealAir

Sorry Rob, I answered Martin before I saw your post ;-)Yes I agree.Soren

Hi All:Just an update to add info about the MSDN ESP SDK docs for those adventurous enough to "tinker under the hood" with aircraft sound sets:http://msdn.microsoft.com/en-us/library/cc526952.aspxBTW: ESP SDK docs are nearly identical in content, but more clearly laid out and IMHO, better explained than... FSX SDK docs. :( < Ahem >... Nice to see a better "free alternative" for docs we PAID extra to get with FSX "Deluxe" and Acceleration or FSX "Gold" SDK packs ! :( PS: ANY legacy FS sound set can theoretically be updated for use with FSX by use of a sound (WAV) file editor.Ex: One can add the FSX "Sound Cone" info, make Stereo into right or left channel only, make Stereo into Mono etc.I look forward to seeing posting of more new and/or converted FS aircraft sound sets in the future... :wink:Hope this helps ! :( GaryGB

Has anyone noticed that if you change just one throttle in a two engined aircraft (so as to put the engine sounds out of phase) that the sound will stay out of phase no matter what throttle setting you apply, even moving the throttle back to the exact same place so that engine speeds are identical (at idle for example) results in there being no phasing at all ever. It seems almost impossible to make them phase again, that is until you change the view from internal to external or vice versa, as soon as you change view the phasing is back instantly, if the engine speeds match of course. Give one of the throttles a tweak for a second or so the move it back again and the phasing is gone again until you switch view again.I've tried fixing the horrid phasing in the F1 Mustang that aircraft has got to have the most prominent phasing of any sound sets I've ever come across in FSX. I tried creating reversed files for the combustion and whine sounds and adding the new filenames into the sound.cfg but it didn't work, I just ended up with sounds working for the left hand engine only and all cone effects were completely gone too, moving the right throttle didn't illicit any change in any sound at all, all I did was create reversed files and name them differently i.e. added _r to the filenames and then adjusted the filenames in the sound.cfg accordingly.Does anyone know if the Wavs have to be mono when you have separate files for each engine in a two or more engined aircraft, or does it not matter and all Wavs can be in stereo?