Audio Capabilities of RecDual Dongle

RecDual Dongle offers versatile audio recording capabilities, supporting embedded audio from video sources and external audio input through the AUX port.

Audio Specifications

  • Audio Encoding: AAC

  • Sample Rate: 48kHz

  • Bitrate: 192Kbps

  • Channels: Stereo (2.0)

Audio Sources

HDMI Audio

  • Audio embedded in the HDMI signal is automatically recorded

  • No additional configuration needed

  • Supports stereo audio from any HDMI source

Type-C DP Audio

  • Audio is automatically captured through the DisplayPort signal

  • Device system audio is embedded in the recording

  • Stereo output recorded to video file

AUX Input (3.5mm)

  • 3.5mm TRRS (4-pole) jack

  • Dual-function port:

    • Microphone Input: Connect external microphone for commentary

    • Line Output: Connect headphones for audio monitoring

AUX Port Features

The AUX IN port supports multiple use cases:

As Microphone Input

  • Connect a 3.5mm microphone to add voice commentary

  • Microphone audio is mixed with source audio in the recording

  • Ideal for:

    • Game commentary

    • Tutorial narration

    • Presentation voiceovers

As Line Output

  • Connect headphones to monitor audio during recording

  • Hear the source audio while recording

  • Essential when recording from Type-C DP (device speaker is disabled)

Headset with Microphone

  • A headset with built-in microphone can provide both functions

  • Monitor audio while adding commentary

  • Use standard TRRS (4-pole) headset

Important: Type-C DP Audio Behavior

When recording from a mobile device via Type-C DP:

Warning

Type-C DP takes over the device’s audio output channel.

  • The device’s built-in speaker will not work

  • This is normal behavior, not a malfunction

  • Audio is still being recorded to the video file

How to hear audio during Type-C DP recording:

  1. AUX Port: Connect headphones to the RecDual Dongle’s AUX port

  2. HDMI Passthrough: Connect the HDMI OUT to a TV or monitor with speakers

Tip

If you need to hear audio while recording from your phone, always have headphones ready to connect to the AUX port.

Audio Recording Tips

For Best Audio Quality:

  • Use the source device’s audio at moderate volume levels

  • Avoid audio clipping by not setting volume too high

  • For microphone recording, use a quality external microphone

For Commentary Recording:

  • Position microphone at appropriate distance

  • Test audio levels before starting important recordings

  • Consider using a headset for simultaneous monitoring and commentary

For Music or Media:

  • Ensure source audio is not muted

  • Check that audio is routing through HDMI or Type-C DP

  • Some apps may require specific audio output settings

Limitations

  • No support for surround sound (stereo only)

  • Cannot record phone call audio through Type-C DP

  • Built-in microphone not included - external mic required for commentary