User Manual
Pearl-2 User Guide Adjust audio gain and delay
If the gain of your analog audio signal needs adjustment, monitor the audio levels using the VU meter and
headphones, then add some gain using the Admin panel. As a rule, each 10 dB of gain doubles the perceived
loudness of the audio signal.
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.
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.
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.
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To avoid unwanted signal noise on the RCA ports, we recommend adding no more than 12dB of gain to the RCA ports or
when XLR B/RCA is used, see Assign audio sources to an input.
Table 26 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.
RCA Nominal
Professional mixer
XLR Nominal
RCA 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.
Ensure the audio input source is connected to an analog audio input port on Pearl-2 before proceeding.
To adjust the gain and delay for an audio source:
1. Login to the Admin panel as admin. See Connect to the Admin panel.
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