d&b audiotechnik A1 Mainframe F-Series, Руководство пользователя

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(4.0E) 3-3
MUTE (red)
This switch mutes the system output without having to alter any of
the system level settings. The mute circuit acts by electronically
disconnecting the mainframe power amplifier output. The red LED
next to the MUTE switch illuminates to verify that the switch has
been selected.
If cabinets used in an array are muted, the movement of the
loudspeaker cones in those cabinets is no longer damped by the
influence of the mainframe power amplifier output. The removal of
damping to some drivers in an array makes them susceptible to
excitation by the other loudspeakers in the array. Audible
resonances may occur, and even absorption of low frequency
sound energy as the undamped loudspeakers act like a ‘bass trap’.
To permanently mute single cabinets of an array it is therefore
preferable to turn down or disconnect the input signal of the
corresponding controllers instead of using the MUTE switch.
When the mainframe is connected to the d&b remote control
system (d&b RIB and PC) it is possible to use the minimum input
gain setting (–57.5 dB) instead of the MUTE function.
Level control
The detented level control adjusts the controller input sensitivity
and has a 20 dB range, calibrated in 1 dB steps. The level control
is normally set to 0 dB. On 1220 and F2 controllers, to the right of
the level control is an HF level control which sets the relative level
of the HF signal from about 1 kHz upwards.