[INVESTIGATING]A10C Sound Update - Premature 'Firecracker' Sound

[Aarnoman]

I would like to preface this bug report by thanking the ED team for the excellent work on the A10C sound update. It has been a phenomenal improvement to the soundscape, the team members involved should be very proud of their work.

However, one small issue was introduced with the change, relating to the time of onset of the 'firecracker sound'. I have created a video to more clearly demonstrate the bug, why it is an issue, and how it compares to real life footage.

Please take the time to watch the video, as it much more clearly demonstrates what I mean, it is very difficult to explain in words alone.

 

 

Now on to the bug:

Version: 2.5.6.57264

Bug description: First part of Gau8 impact sound plays prematurely (before round impacts).

 

Detailed report:

Terminology: Effectively, with the sound update introduced in the 2.5.6.57264 update, there are now three distinct parts to the Gau-8 soundscape:

1. [sound 1] The ‘firecracker’-like initial sound.
   
2. [sound 2] The thudding impact sounds, in time with the explosions. These appear to be unchanged from the old impact sounds present prior to the sound update.
   
3. [sound 3] The ‘brrrrt’ sound originating from the gun.
   

Additionally, it should be noted DCS utilises realistic speed of sound delay to in game sounds, and has been considered in the demonstration of this bug.

 

Bug in action:

Currently, [sound 1] and [sound 2] should be occurring simultaneously, as both are caused by weapon impact with the ground. However, [sound 1] currently occurs prematurely – slightly before any rounds have impacted.

This results in noticeable splitting between these two sounds, especially at increased distance from target.

Demonstration video 1:

 

I have compared the sound to many videos of A10C gun runs, with all demonstrating [sound 1] and [sound 2] occur simultaneously.

Examples include:

(included in demonstration video)

(a compilation video, only some clips relevant)

 

For in game comparison, here is a second demonstration video also showing this split of [sound 1] and [sound 2]:

 

The mission used for testing is attached, with the vehicles serving as distance markers. Use F7 to reach the appropriate vehicle to observe from, the AI A10C will make passes every ~2 minutes.

A10AudioTest.miz

[btd]

Many thanks for your investigation. But the firecracker and impacts sounds should not be connected to each other. They are independent.

1st one, the ‘firecracker’ sound, is the sound of the sonic boom effect from the shells, that pass by the listener. You can fire in the air and there won't be any impacts. But there will be the ‘firecracker’ sound, if your camera stays in the front of the plane. And there will be no any ‘firecracker’ sound if you are behind the plane. But in this case you can hear the impacts sound.

So the time between the 1st and the 2nd sounds depends on two parameters: 1) how far are you from impacts on the ground and 2) when the shells fly past the camera and make the "sonic boom" effect

 

Although you may be partly right and the time of flight of the projectiles past the camera is calculated not quite correctly. We'll investigate that. Thanks

Edited November 6, 2020 by btd

[Aarnoman]

Many thanks for your investigation. But the firecracker and impacts sounds should not be connected to each other. They are independent.

1st one, the ‘firecracker’ sound, is the sound of the sonic boom effect from the shells, that pass by the listener. You can fire in the air and there won't be any impacts. But there will be the ‘firecracker’ sound, if your camera stays in the front of the plane. And there will be no any ‘firecracker’ sound if you are behind the plane. But in this case you can hear the impacts sound.

So the time between the 1st and the 2nd sounds depends on two parameters: 1) how far are you from impacts on the ground and 2) when the shells fly past the camera and make the "sonic boom" effect

 

Although you may be partly right and the time of flight of the projectiles past the camera is calculated not quite correctly. We'll investigate that. Thanks

 

Thank you for that explanation, I was not aware that the firecracker sound was a result of supersonic cracks rather than impact.

 

With that information, I still think there is an issue with time of flight and onset of the firecracker sound, which you appear to have identified as well.

I am basing this off the fact that the muzzle velocity of the Gau-8 projectiles is ~1010 m/s, which is considerably faster than speed of sound (340m/s).

At the ranges used in testing (please refer to attached mission file for replication), the firecrack sound still appears noticably earlier than any projectile impacts when observing from the target location. This should not be possible as the projectiles were travelling at supersonic speed for the entire duration.

Thank you for taking the time to reply and statement to investigate this further.

If I am correct in thinking you are one of the staff member responsible for developing this update to the soundscape, I want to once again commend you on the awesome work. It really is a game changer for me personally. Thank you.

 

[btd]

Thank you very much!

Yes, you are correct, and there are deviations in the calculation of the appearance of the sonic boom sound. However, to correct them, we will have to edit the main core sound engine of the DCS and involve the main programmers. So please don't expect a quick fix.

[Aarnoman]

Thank you very much!

Yes, you are correct, and there are deviations in the calculation of the appearance of the sonic boom sound. However, to correct them, we will have to edit the main core sound engine of the DCS and involve the main programmers. So please don't expect a quick fix.

 

Thank you for investigating it, great to hear that the likely culprit has been identified. Looking forward to it being fixed down the line, no rush. Just happy it's been looked at.

Thanks again for the awesome improvement you've brought to the soundscape.