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Two‑Way Audio

BliKVM v1/v2/v3 supports two‑way audio. This works a bit differently from typical software voice calls: on the web side, the audio is sent to the controlled PC via a USB microphone emulated by the KVM. Therefore, if you want the web user and the user at the controlled PC to talk directly, the controlled PC also needs to be configured accordingly.

Two‑way talk demo video

Audio path overview​

Downlink (Controlled device → Web):

Controlled host HDMI audio
    │
    ▼
KVM capture card (HDMI→CSI/Audio)
    │
    ▼
Janus (WebRTC transport)
    │
    ▼
Web browser (speaker playback)

Uplink (Web → Controlled host):

Web browser (local microphone capture)
    │
    ▼
Janus (WebRTC transport)
    │
    ▼
KVM backend (forwards audio data)
    │
    ▼
Virtual USB microphone (exposed as a mic device on the controlled host)
    │
    ▼
Controlled host (receives audio from microphone)

Note: “Janus (WebRTC transport)” refers to transmitting audio via a WebRTC channel over LAN/Internet. “Virtual USB microphone” is the microphone device visible on the controlled host.

Play HDMI audio and enable the microphone​

  • Click the overlay to reveal the microphone and audio playback controls at the bottom‑left of the video window.
  • To play HDMI audio in the web UI, toggle the unmute/mute audio button.
  • To send web audio into the controlled PC, go to the Settings panel on the left and click Register microphone to register the microphone in the KVM backend. After successful registration, you should see an additional microphone device in the OS sound devices on the controlled PC. Note: if audio still doesn’t reach the controlled PC during testing, try rebooting the KVM after registering the microphone and test again.
  • After the microphone is registered, use unmute/mute microphone to enable or disable the mic. The first time you allow microphone access, the browser will prompt you to choose which microphone to use. To change the web input microphone later, adjust it in your browser’s settings.

How to play the KVM microphone audio on the controlled PC​

Search for how to monitor (listen to) a microphone to speakers on your OS. For example, on Windows, open the Sound settings, find the relevant microphone, enable “Listen to this device,” and route it to a speaker on the controlled PC so audio plays directly there.

How to capture the controlled PC’s microphone audio into the KVM​

Search for how to route your PC’s microphone to an HDMI audio output device. For example, on Windows, in the Sound settings, find the microphone, enable monitoring (listen), and route it to the KVM’s HDMI audio device.