Bluetooth output driver downsampling


When playing Unity game audio via stereo bluetooth headphones (in this case, Apple AirPods) with a 48k sample rate, audio output is downsampled.

Using CoreSystem.getDriverInfo, I was able to confirm that the device is indeed being identified as 24k and mono.

My computer’s system settings reflected this; when game audio is played through this device, the sample rate, which normally displays the default device sample rate, also showed 24k, and returns to the default value of 48k once the game is stopped.

I did some reading on the forums and saw that a similar behavior was observed on mobile devices due to a mobile platform default sample rate. On the off chance the headphones’ bluetooth packet included a mobile flag, I updated platform sample rate settings in both FMOD Studio and Unity’s FMOD settings, but this had no effect.

Any guidance would be much appreciated!

FMOD version: 2.00.22
Unity Version: 2020.3.46f1


Unfortunately, we no longer support FMOD 2.00. Could you please update to either 2.01 or 2.02 and test again?

Migrating through major versions is outlined here: FMOD Studio | Advanced topics - Migrating FMOD Studio Projects.

Hi Connor, thanks for your reply.

We are quite close to entering cert, so I’m not sure we can pull off a major version migration, but I’ll test this out in a more recent version to see if I can reproduce the behavior there in case a potential remedy might also be applicable to the version we’re on.

1 Like


I understand, if you can replicate this behavior in a later version of FMOD I can definitely look into it for you.