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AM844D
English
23. High Frequency Control
Use it to give a shelving boost or cut
of ±15 dB to high frequency (12 kHz)
sounds. This will adjust the amount
of treble included in the audio of
the channel, adding strength and
crispness to sounds such as guitars,
cymbals, and synthesizers.
24. Middle Frequency Control
You can provide a peaking style of
boost and cut to the level of middle
frequency sounds at a range of ±15
dB with this control. The AM 844D
mixer also provides a sweep control,
allowing you to select a center
frequency between 100 Hz and 8
kHz. Changing middle frequencies of
an audio feed can be rather difficult when used in a professional
audio mix, as it is usually more desirable to cut middle frequency
sounds rather than boost them, soothing overly harsh vocal and
instrument sounds in the audio. The stereo channels of the AM
844D mixer feature a High-Mid and Low-Mid control instead of the
typical controls described above. They provide a peaking style of
boost and cut to middle frequencies, where the frequencies are
set at 3 kHz and 800 Hz for the High- and Low-Mids respectively.
25. Low Frequency Control
This control is used to give a shelving boost or cut of ±15 dB
to low frequency (80 Hz) sounds. This will adjust the amount of
bass included in the audio of the channel, and bring more warmth
and punch to drums and bass guitars.
26. AUX Controls
These four AUX controls alters the
signal level that is being sent to
the auxiliary 1 to 4 mixing buses,
the signal of which is suitable for
connecting stage monitors, allowing
artists to listen to the music that is
being played. AUX 1 and 2 feature a
Pre/Post button, which alternates the
feed to the AUX mixing bus between
a post and pre-fader feed. AUX 3, on
the other hand, acts as an EFX send,
the signal of which can be used in
conjunction with external signal
processors (which can be returned to
the mixer via the AUX return input),
or simply as an Auxiliary output. Both
the AUX 3 (EFX) and AUX 4 controls
are post fader and are sent directly
to the corresponding outputs.
27. Pan / Balance Controls
This alternates the degree or level of
audio that the left and right side of the main mix should receive.
On mono channels, the PAN control will adjust the level that the
left and right should receive (pan), where as on a stereo channel,
adjusting the BAL control will attenuate the left or right audio
signals accordingly (balance).
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CONTROLS AND SETTINGS
Rear Panel
18. Power Switch
You can use it to turn the mixer on
and off. Ensure you turn all level
controls down before activating.
19. Phantom Power Switch
When this switch is in the on position,
it act48V of phantom power
for all microphone inputs, allowing
condenser microphones (well, the
ones that don’t use batteries) to
be used on these channels. Activating Phantom Power will be
accompanied by an illuminated LED above the left channel Level
Meter. Before turning Phantom Power on, turn all level controls
to a minimum to avoid the possibility of a ghastly popping sound
from the speakers.
NB.
Phantom Power should be used in conjunction with balanced
microphones. When Phantom Power is engaged, single ended
(unbalanced) microphones and instruments should not be used on the
Mic inputs. Phantom Power will not cause damage to most dynamic
microphones, however if unsure, the microphone’s user manual should
be consulted.
Channel Controls
20. Line/Mic Gain Control
This controls the sensitivity of the input signal of
the Line/Microphone input of mono channels, the
gain should be adjusted to a level that allows the
maximum use of the audio, while still maintaining
the quality of the feed. This can be accomplished
by adjusting it to a level that will allow the peak
indicator occasionally illuminate. On channels
9-10 and 11-12, the gain control affects the
microphone input only, and on channels 13-14
and 15-16, this only affects line inputs (as there
are no microphone inputs on these channels).
21. Low Cult Filter (75 Hz)
Located on channels 1 through to 8, will activate
a high-pass filter that reduces all frequencies
below 75 Hz at 18 dB per Octave, helping to remove any
unwanted ground noise or stage rumble. Stereo channels does
not feature this low cut filter.
22. +4/-10dB Buttons
Located on stereo channels 9-10
and 11-12, these buttons select the
input signal level, allowing the mixer
to better adapt to different operating
levels. If the input source is -10 dBu
(consumer audio standard), it is best to
engage the switch, allowing the signal
to be heard. If the input source is +4
dbV (professional audio standard) the
corresponding input channel’s button
should be disengaged to ensure the
integrity of the Mixer’s circuitry. If you
are unsure of the source’s operating
level, we suggest leaving the switch
disengaged until you test the source’s signal. You can then
engage if necessary (if the level of input is obviously too low).
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