Adjust audio gain and delay

Pearl-2 does not introduce audio delay and has near-zero latency when capturing. However, other external factors can cause audio to become de-synchronized, such as the length of audio cables or the configuration of your equipment. The audio delay feature helps you adjust audio coming from external sources so that your video and audio sources are synchronized when captured, streamed, and recorded.

You can apply from -300 ms to +300 ms of delay to any audio source using the Admin panel . By default, there's 0 ms of delay applied to audio sources.

The analog audio input ports on Pearl-2 are calibrated for +4.0 dBu XLR or -10.0 dBV RCA audio signals and provide moderate to significant signal headroom. For the analog audio inputs, you can add up to +30 dB of gain.

Microphones typically have low audio signals (less than -30 dBu) and are not supported directly as inputs to Pearl-2. Use an audio mixing board or preamp to amplify microphones and supply the appropriate line level input. See Connecting microphones to the XLR line level inputs.

Adjusting the Input Gain for an analog audio source affects the volume for that audio source in recordings, streamed output, video output ports, and in the headphone jack. Be aware that excessive amounts of gain can increase the perception of any noise that may be present in the audio signal.

If the gain of your analog audio signal needs adjustment, connect your headphones and use the VU meters to monitor the audio level while you add some gain. As a rule, each 10 dB of gain doubles the perceived loudness of the audio signal.

This table offers some guidelines for adjusting the gain at the audio input port of Pearl-2 for common types of audio input devices. You should add the suggested gain to the audio input to get an average signal to register at a nominal level in the VU meter (i.e. where the green bars change to yellow). The actual amount of gain needed depends on the strength of the original audio signal.

Audio input port gains guidelines

Audio source Input port Gain
Mobile phone or other consumer line level device XLR Add +6 to +12 dB gain to the audio input port.
RCA1 Nominal
Professional mixer XLR

Nominal
RCA1 Not recommended.
USB microphone USB Nominal
Dynamic, condenser, or electret microphones XLR

Not recommended.

To connect microphones to the pro line level XLR inputs, you must use an external preamp to boost the microphone signal enough to provide the proper line level signal at the XLR input port, see Connecting microphones to the XLR line level inputs.

1 To avoid unwanted signal noise on the RCA ports, we recommend adding no more than 12dB of gain to the RCA port or when XLR B/RCA is used, see Assign audio sources to an input.

Ensure the audio input source is connected to an analog audio input port on Pearl-2 before proceeding.

Adjust the gain and delay for an audio source using the Admin panel

  1. Login to the Admin panel as admin. See Connect to Admin panel.
  1. From the Inputs menu, select an audio source. The audio configuration page for the audio source opens.

  1. In the Input Gain field, select the amount of gain to apply to the audio source.
  1. In the Audio delay field, enter a value between 300 and -300 ms. A positive value adds delay to the audio signal. A negative value adjusts the audio to start earlier.
  1. Click Apply.