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5. Speaker Operation
Once installed and connected, switch the power on. The LED behind the grille will
illuminate either green or red, and a rising audio tone will be heard. You should hear audio
through the speaker now. Turning the “Volume” control clockwise or anticlockwise will
increase or decrease the volume level, at the same time you will hear a low frequency
audio sound through the speaker when the volume control is turned. The volume of this
audio “blip“ sound will vary as you rotate the volume level control knob. Subsequent
presses of the “Volume” control knob will turn the speaker on and off. When switching
back on the speaker will go to the last stored setting when switched off.
Pressing the filter level control knob switches the DSP noise cancelling filter on and off, a
red LED indicates filter off, and a green LED filter on. The filter level is simply changed by
turning the filter level control knob clockwise or anticlockwise. There are 8 filter levels
indicated by 8 different frequency tones. The lowest tone indicates the lowest filter level
and the highest tone indicates the maximum filter level. You can easily adjust the filter
level to suit your current operating conditions.
Note: If the power is on and the DSP is switched off (red LED), the audio passes through
the DSP filter, but without any signal processing.
6. Speaker Tone Level Volume Adjustment
There are four volume level settings for the audible speaker tones; off, low, medium and
high. To change the tone volume level to your preferred setting, press and hold the
volume control until you hear an audible tone and the LED flashes continuously. Release
the volume control to select the current level, otherwise press and hold the volume knob
again until you hear the next tone. (Note that with the audio tone in position off, only the
LED will flash when the volume control is pressed).
7. Sleep Mode
The DESKTOP speaker has a built in sleep mode feature whereby it will be put into
standby mode when there is no signal present after approx 60 minutes. This is indicated
by falling tones. In this mode the speaker only draws a small amount of current (approx
10mA). The speaker will be woken up if a signal is received whilst in sleep mode. This is
indicated by rising tones. If the speaker is switched off manually by pressing the volume
control knob momentarily with power still applied, the sleep mode is inactive and to wake
the speaker up in this instance, press the volume control knob again and the speaker will
switch on, with the last known settings restored.
The sleep mode function can be turned off and on by pressing and holding the filter level
control knob for approx 4 seconds. Falling tones indicate that the sleep mode is enabled,
and rising tones indicate that the sleep mode is disabled.
8. Input Overload
The DESKTOP has audio input overload protection for both the line level and speaker
level inputs. If the signal peaks go over the limits set out in the specification, the LED will
change red and flash 3 times. If the audio level is constantly above the overload
