High/Low Mid Eq; Freq; Low Eq; Pan - Mackie 1620 Owner's Manual

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High Mid EQ
the most dynamic because the frequencies that defi ne
any particular sound are almost always found in this
range. The HIGH MID EQ range (400 Hz to 8 kHz)
includes the female vocal range as well as the funda-
mentals and harmonics for many instruments.
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20 100 1k 10k 20k
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Low Mid EQ
mentals of some lower instruments (guitar, lower brass).
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Hz Hz Hz Hz
Mid EQ Freq Sweep
narrow band of frequencies you want to have affected by
the LOW MID and HIGH MID EQ.
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Hz Hz Hz Hz

Low EQ

Note: Used in conjunction with the Low Cut switch,
you can boost the LOW EQ without injecting tons of
infrasonic debris into the mix.
Short for "midrange,"
this knob provides 15 dB of
boost or cut centered at the
frequency determined by
its FREQ knob (see FREQ
next), or at 2.5 kHz for the
stereo channels. Midrange
Hz
EQ is often thought of as
This is a second midrange
EQ control that provides 15
dB of boost or cut centered
at the frequency deter-
mined by its FREQ knob.
It extends down to 100 Hz,
which includes the male
Hz
vocal range and the funda-
This knob ranges from
100 Hz to 2 kHz for the
LOW MID EQ, and 400 Hz
to 8 kHz for the HIGH MID
EQ. This determines the
center frequency for the
EQ fi lter, and allows you
20k
Hz
to zero in on the precise
This control gives you
up to 15 dB of boost or cut
at 80 Hz. The circuit is fl at
(no boost or cut) at the
center detent position.
This frequency represents
the punch in bass drums,
20k
Hz
bass guitar, fat synth
patches, and some really
serious male singers.
These tap a portion of each channel's signal out to
either an effects processor or for stage monitoring. The
AUX Send levels are controlled by the channel's AUX 1-4
knobs, and by the AUX MASTER 1-4 knobs.
Since the AUX Sends are mono, the left and right sig-
nals in the stereo channels are summed together prior
to the channels' AUX 1-4 controls, sending the combined
signal to the AUX SEND outputs.
These are more than just effects and monitor sends.
They can be used to generate separate mixes for record-
ing, for another zone, or "mix-minuses" for broadcast.
PAN adjusts the amount of channel signal sent to the left
versus the right outputs. On the stereo channels (channels
9-16), the PAN knob works like the balance control on your
home stereo (panning left turns down the right channel,
and panning right turns down the left channel).
With the PAN knob hard left, the signal feeds either
the MAIN LEFT (bus 1) or ALT LEFT (bus 3), depend-
ing on the setting of the ALT 3/4 switch. With the knob
hard right, the signal feeds either the MAIN RIGHT
(bus 2) or ALT RIGHT (bus 4).
Constant Loudness: The Onyx 1620's
PAN control employs a design called
"Constant Loudness." If you have a
channel panned hard left (or right)
and then pan to the center, the signal
is attenuated about 3 dB to maintain
the same apparent loudness. Otherwise, it would make
the sound appear much louder when panned center.
The dual-purpose MUTE/ALT 3-4 switch is a Mackie
signature. When Greg was designing our fi rst product,
he had to include a mute switch for each channel. Mute
switches do just what they sound like they do. They turn
off the signal by "routing" it into oblivion. "Gee, what
a waste," Greg reasoned. "Why not have the mute
button route the signal somewhere else useful, like
a separate stereo bus?" So MUTE/ALT 3-4 really serves
two functions—muting (often used during mixdown or
live shows), and signal routing (for multitrack and live
work) where it acts as an extra stereo bus.
To use this as a MUTE switch, all you have to do is
not use the ALT 3-4 outputs (41). Then, whenever you
assign a channel to these unused outputs, you'll also be
disconnecting it from the MAIN MIX, effectively mut-
ing the channel. The MUTE switch also disconnects the
channel from the POST AUX SEND bus. The channel's
signal is still present on the PRE AUX SEND bus.