Focusrite Scarlett 18i20 User Manual page 31

Monitor level control knob
Set the output level of all selected outputs with this control, using the mouse. The
numeric display below shows the current monitor output level.
Hardware control button
Clicking this button transfers control of overall monitoring level between the Scarlett
MixControl and the Scarlett 18i20's front panel VOLUME MONITOR control. When
enabled, the button shows blue and the on-screen knob is disabled.
Note: if the hardware control position does not match the software control position as
the H/W Control button is switched in and out, the volume knob works in pick-up mode.
A volume change will only occur when the position of the hardware knob matches or
passes through the position commanded by the software control. This will ensure that
there are no sudden unwanted volume increases when the knob is moved.
Dim
Attenuates the monitor output level by 18 dB.
Mute
Mutes all monitor outputs.
Left Mute switch
Mutes all odd-numbered outputs.
Right Mute switch
Mutes all even-numbered outputs.
Mono switch
Sums (combines) the odd- and even-numbered output signals in pairs (i.e., 1+2, 3+4, etc.).
The summed signals are then sent to both outputs of each pair.
NOTE: Remember that the monitor functions above only affect the outputs that have been selected
for control in the monitor control section (i.e., outputs showing 'blue' status).
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