P51D and TF-51 sound issue...

[M1Combat]

When I increase manifold pressure across 48.5" I get an instant hiss. At lower manifold pressure the sound is there but very quiet. As soon as I go over 48.5 the volume of this hiss increases substantially. I have messed around listening to the sound files in the P51 folders and it seems as though the sound I'm hearing is \Sounds\Effects\Aircrafts\Engines\PackardMerlinProp\Cockpit\PropIn1.Wav or the \Sounds\Effects\Aircrafts\P-51D\PlaneWind.Wav sounds but I'm not sure.

 

I've recorded a video of the sound and that can be found here...

 

https://drive.google.com/file/d/0B_1ch17SXraVcW5QTUR4NFZWSGs/view?usp=sharing

 

Or here

 

 

You'll need to turn the volume up on the youtube link. It seems that maybe Youtube has a hiss reduction algorithm that made the issue less obvious but it is there.

 

 

 

 

I do run a sound mod so last night I completely wiped my install and tested with a freshly downloaded an installed copy with no mods. It was still there. I have also tested with other planes and the issue doesn't happen with at least the other WW2 planes, the F15 or the F86. All of the other planes sounds perfect with no issues. Very clean.

 

I have changed my sound setting in Windows to 16b 44.1Khz and 48Khz as well as the 24b settings of those ranges as well. I am not running any enhancements in the audio driver (room correction, speaker fill, loudness equalization etc...) and I have no EQ running at all. I have gone through and toggled each of the mode options I have in my sound drivers (Stereo, Dolby, 5.1, Game mode, Music Mode, etc...) with no change.

 

I race the P51 in Shahdoh's Mustang Racing series (link here - http://www.virtual-aerobatics.com/forum/viewforum.php?f=18) and have asked some of the other pilots if they get this sound and they don't.

 

Any ideas?

 

Thanks in advance.

Edited July 20, 2015 by M1Combat

[Destroyer37]

Very interesting, I don't recall having this issue myself at least that I can remember. Ill have a look when I get back to my computer.

[Art-J]

Yep, it's there indeed. Can we have a recording of an unmodded plane too?

[Solty]

I thought that it might have been the radiator making the noise. But if its tied to MP that's weird. What is its purpose? Was it suppose to be high speed air sound?

[M1Combat]

Yep, it's there indeed. Can we have a recording of an unmodded plane too?

 

The same thing happens on a completely unmodded fresh install. For said fresh install I deleted all files including the game directory and the saved games directory. I didn't even touch the settings.

[M1Combat]

But if its tied to MP that's weird.

 

I don't think it's related to MP. It happens in SP and MP.

[Solty]

I don't think it's related to MP. It happens in SP and MP.

 

I meant Manifold Pressure MP :3

[Echo38]

I usually see manifold pressure abbreviated as MAP (for "manifold absolute pressure") in period documents. Not being an engine expert, I don't know if there's a distinction between "manifold pressure" and "manifold absolute pressure," where WWII fighters are concerned.

[Art-J]

Should be MAP indeed. But, if the "hiss" is present with stock samples as well, that sounds like a hardware issue.

[btd]

That "hiss" coming from actuator's sounds, which you can find here - ...\LockOnExe\Sounds\Effects\Aircrafts\P-51D\Cockpit\Actuator....wav

They can turn on and off during the flight in some cases.

You'll never hear it with the original sounds, as it must be. Engine sounds must be very very loud. In your video they're almost dead :) that's why you can hear something unfamiliar.

 

You can make your engine sounds louder in your mod, or make these actuators sounds quieter. Second option is no good, imho.

[M1Combat]

That "hiss" coming from actuator's sounds, which you can find here - ...\LockOnExe\Sounds\Effects\Aircrafts\P-51D\Cockpit\Actuator....wav

They can turn on and off during the flight in some cases.

You'll never hear it with the original sounds, as it must be. Engine sounds must be very very loud. In your video they're almost dead :) that's why you can hear something unfamiliar.

 

You can make your engine sounds louder in your mod, or make these actuators sounds quieter. Second option is no good, imho.

 

I'll give that a shot.

 

To be clear though... The sound jumps in volume by I'd say a factor of 4x the moment the MAP crosses 48.5" and drops back to very quiet as soon as the MAP drops back under 48.5". Never any variability and it happens every time. Wouldn't an actuator be more random?

 

Also...

 

Do you mean adjusting the volume of that sound by editing the file or by editing the gain in the associated sdef file?

--------------------------

 

OK So I've just gone and had a listen to the files you point out. I hear those sounds when I manually activate the oil and/or coolant radiator openings. They're bound directly to my HOTAS configuration. Being a racer of the TF-51 I'm constantly adjusting both of those to keep the engine cool and reduce drag to an absolute minimum. I almost never fly with them in Automatic mode. Based on this I'm almost certain that these aren't the sounds I'm hearing. That said... I'll certainly go and adjust the gain in the sdef files for those sounds and make sure.

Edited July 22, 2015 by M1Combat

[Yo-Yo]

I'll give that a shot.

 

To be clear though... The sound jumps in volume by I'd say a factor of 4x the moment the MAP crosses 48.5" and drops back to very quiet as soon as the MAP drops back under 48.5". Never any variability and it happens every time. Wouldn't an actuator be more random?

 

Also...

 

Do you mean adjusting the volume of that sound by editing the file or by editing the gain in the associated sdef file?

 

Actuator does not depend on MP. It depends only on coolant tempetature that depends on many factors.

[M1Combat]

Alright I've just gone and tested the coolant/oil actuator suggestion...

 

If I manually close the radiator tunnel I can hear the actuator and it is not the errant sound I'm hearing. As a second confirmation I closed the radiator while increasing MAP setting and can clearly hear both noises. The actuator being constant and dependent on whether I'm holding the button down and the other issue being based entirely on whether my MAP setting is above or below 48.5.

 

btd - If you could do some research and find out what changes in the sounds at exactly 48.5MAP I would be VERY appreciative. I do suspect it's a gain setting somewhere but without knowing which sound starts based on MAP setting going over 48.5" I won't be able to hunt it down.

Edited July 22, 2015 by M1Combat

[M1Combat]

Anyone else have any ideas? I can confirm the sound is not either of the cooling tunnel actuators. I went and turned up the gain in the .sdef file for the actuators to be certain and it most certainly is not those that are making the noise. I have also gone through and turned up the gain on each sound file that sounds like it has any chance at all of being this noise and it does not change the volume of the sound I'm hearing.

 

Also... I don't get this sort of effect in any other game. I do indeed think it's a hardware issue... but it's something about how the hardware interacts with this software alone. My hardware is a set of GameCom 780's. They're quite good in all other games and music is clear as glass. The reason I believe it is DCS that causes the issue (aside from the lack of issue anywhere else) is that it kicks in at exactly 48.5" MAP and disappears when the MAP is reduced below 48.5"...

 

Please help :).

 

Anyone else have a set of GC780's and do not have this issue? For the record the issue occurs in the TF-51 as well as the P-51 so anyone with a set of GC780's should be able to report. One more thing on this subject... I removed the GC780 driver, which reverts the headset to a generic audio device, and the issue persisted. I do have an on-board sound card (that is currently disable in the BIOS) and I'll remove the GC780's and enable that, then try. Of course that's not a solution for me as I love the GC780's but we'll see if it works.

 

Thanks in advance.

Edited July 23, 2015 by M1Combat

[M1Combat]

Actuator does not depend on MP. It depends only on coolant tempetature that depends on many factors.

 

Understood.

 

The point I was getting at was that the sound IS dependent on the MP setting, indicating that the sound IS NOT the actuator, not that the sound was the actuator and that the actuator was dependent on the MP setting.

[Jacks]

Was this issue every resolved. I'm have similar problem that when MAP is above about 40", I cannot hear any engine noise at all and the remainder if the flight is silent. Sometimes I hear the engine if Imadvance the throttle to full power. I have had this problem since installing DCS and a fresh install did not resolve the problem.

 

It would be nice to hear the engine during dogfights rather than having to constantly check the instruments.

 

Jacks