Elgato 4K S audio works in Windows and Elgato Studio, but not in OBS Studio

[まねきねこ]

Hello,


I am having an audio capture problem with OBS Studio and an Elgato 4K S.


My setup is:

• Nintendo Switch 2
• Elgato 4K S
• Windows PC
• OBS Studio
• Switch 2 → HDMI → Elgato 4K S → USB-C → PC

The video works perfectly in OBS, but the audio does not.


Here is what I have confirmed:

• Elgato Studio receives the Switch 2 audio correctly, and the audio meter moves.
• Elgato Studio is set to HDMI Audio.
• Windows recognizes HDMI (Elgato 4K S) as an audio input device.
• Windows' audio test works and shows about 18% volume.
• The Windows input volume is set to 100% and the device is not muted.
• The device status says "This device is working properly."
• The device format is 2 channels, 16 bit, 48000 Hz.
• OBS is also set to 48 kHz.
• Windows microphone/privacy permissions are all enabled.
• I disabled exclusive mode for the Elgato audio device, but this did not help.
• I also tried running OBS as administrator, but there was no change.
• In OBS, I tried adding Audio Input Capture and selecting HDMI (Elgato 4K S) directly.
• However, the OBS audio meter remains at 0 and does not move.
• I also tried using the audio from the Video Capture Device, but the meter still does not move.

So the audio seems to work correctly through:


Nintendo Switch 2 → Elgato 4K S → Elgato Studio / Windows


but not through:


Nintendo Switch 2 → Elgato 4K S → OBS Studio


What could be causing OBS to not receive the audio even though Windows and Elgato Studio can receive it?


Is there any specific OBS setting, driver issue, or diagnostic procedure I should try?


Thank you for your help.