Bluetooth/Airpods give poor audio, only in GZDoom.

[Da_maniaC]

Hello all,

Recently i have made a small change to the way i play games, when my headset died. I decided to buy a pair of Apple Airpod Pro's to replace both my gaming headset audio and have a pair of in-ears to take with me outside.

Now i am noticing something really weird...whenever i play GZDoom the sound quality of the game seems way crappier then with any other Headset or Speakerset that are connected using regular jack plugs.

- The strange thing is...this only happens in GZDoom. Even in ZDoom the audio sounds better (there seems to be more low-end to the sound effects especially).
- When i use the Airpods to play any other game (Doom Eternal, WoW, Elder Scrolls Online), the audio quality between the Airpods and any other wired in-ears i own is nearly identical.
- When i use the Airpods to play any type of music on my PC the audio quality between the Airpods and any other wired in-ears i own is nearly identical.

I swear, the only time i am noticing quite a difference in sound quality is when i'm playing GZdoom. The difference is night and day.

Having that said, i know that there are some situations where Bluetooth headsets like the Airpods are triggered into "communication mode". This means the device is no longer active as a Stereo playback device but actually changes to a Mono playback + Mono micophone input device
and audio quality is basically cut in half. I am not exactly sure about the Playback mode the Airpods switch to. Whether this could be from 48kHz Stereo to 16kHz Mono (or even Stereo) but it seems to be something along those lines.
This 'worse' audio quality that is experienced in this mode seems very similar to the audio playback i am getting when i am playing GZDoom.

So my issue and/or follow up questions are:
1. Has anyone else experienced similar complaints such as this in GZDoom?

2. Could there be any sort of code/functionality in GZDoom that could trigger the configuration of the Playback device to be switched back to the so called 'communication mode'..maybe during the startup of the game ?
Its almost as if something is triggering the Playback Device to initialize in 16kHz mode or to initialize it with the Microphone active (if present).

Coincidentally i found this article from someone explaining a rather similar complaint but in a different situation (where the user starts a VM).

[wildweasel]

Out of curiosity, what sound device does GZDoom report that it's using in the startup console?

[Da_maniaC]

OpenAL Soft on Headphones (AirPods Pro Stereo)

[Chris]

It might be the HRTF effect you're hearing. GZDoom (or really, OpenAL Soft that GZDoom uses) will automatically enable HRTF when it detects headphones, which produces a binaural mix for better 3D sound positioning compared to plain stereo, Sounds will be made to sound like they're coming from an "external" point around you rather than directly from the headphones. The HRTF profile/dataset used by default is a fairly generic one, which should be decent for a large number of people but won't be terribly amazing (HRTF's effectiveness depends on having dataset aligning with a person's head and ear size and shape, so having one that can work for many people will necessarily not be well-tuned to a given person's head and ears).

If the effect isn't working good for you, or if you really don't like the binaural effect in general, you can disable it by going to Options -> Full options menu -> Sound Options -> Advanced options, then change HRTF to Off and select "Restart sound".

[Da_maniaC]

It might be the HRTF effect you're hearing. GZDoom (or really, OpenAL Soft that GZDoom uses) will automatically enable HRTF when it detects headphones, which produces a binaural mix for better 3D sound positioning compared to plain stereo, Sounds will be made to sound like they're coming from an "external" point around you rather than directly from the headphones. The HRTF profile/dataset used by default is a fairly generic one, which should be decent for a large number of people but won't be terribly amazing (HRTF's effectiveness depends on having dataset aligning with a person's head and ear size and shape, so having one that can work for many people will necessarily not be well-tuned to a given person's head and ears).

If the effect isn't working good for you, or if you really don't like the binaural effect in general, you can disable it by going to Options -> Full options menu -> Sound Options -> Advanced options, then change HRTF to Off and select "Restart sound".

That seems to have done the trick! I can't believe how much fidelity this HRTF seems to take away. The sound was just completely bland/wooly (lot of low and high-end missing).
Now i can finally enjoy GZDoom again together with my Airpods. Thanks!