Left audio channel is louder than the right channel in Metal Gear Solid 2 & 3 [BLUS30847]

[USBDongleGoblin]

Quick summary

The left channel is at times much louder than it needs to be. This issue only seems to sprout up during
cutscenes featuring surround sound. This is pretty apparent when the gunship first passes by in the intro, and when Snake is jumping (in both games).

Details

Seems to me that all of the other audio channels, aside from the left and right ones, are being output via the left channel. Changing how how the audio is downmixed doesn't seem to do much to help.

Dumping audio with audio channels set to 7.1 dumps a file that is completely fine from the looks of it; all the channels are separate.

RPCS3 log file:

RPCS3.log

Comparison with a real PS3:

MGS3 on RPCS3: https://youtu.be/msyQUl6LTAE?t=194
MGS3 on an actual PS3: https://youtu.be/chjuKZqwpjA?t=147

MGS2 on RPCS3: https://youtu.be/2VaTX_TdE6E?t=182
MGS2 on an actual PS3: https://youtu.be/Zg39pXGkZDw?t=320

System configuration:

• OS: Windows 10 64bit
• CPU: Intel Core i9 9900k @ 3.60ghz
• GPU: GeForce RTX 2080
• Driver version: 451.67

[Augusto7743]

Ultimate Marvel VS Capcom 3 also has the same problem.
The left audio channel has problems.
Perhaps others games has the same issue.

[nitroos-ai]

Needs a retest. There were some changes in #11066 and #11977.

[USBDongleGoblin]

Just quickly tested MGS3 & 2, and unfortunately this still seems to occur. :(

[marcoluc97]

@Megamouse here new changes in audio can help?
Like #12186

[capriots]

This was fixed by #12112.
It's actually happening on a PS3 too if you enable Surround 7.1. It's not happening in Stereo or 5.1. Somehow the games get confused in 7.1 and some sound effects are shifted to the left. The extra two channels aren't even being used, they are completely silent.
Previously, RPCS3 always reported that it was outputting 7.1, even if Downmix to Stereo was selected, which is why you couldn't escape this weird bug.

Stereo.mp4

Surround.5.1.mp4

Surround.7.1.mp4