Channel Controls; "U" Like Unity Gain; Gain Control; Low Cut - Mackie 3204VLZ4 Quick User Manual

Channel Controls
The vertical channel strips look very similar, and
have only a few differences between them, Each
channel works independently, and just controls the
signals plugged into the inputs directly behind it.
"U" like Unity gain
VLZ4 mixers
have
a "U" symbol on almost every level
control. It stands for "unil,y gain," meaning no change in
signal level. The labels on the controls are measured in
decibels (dB) so you'll know what you're doing
level-wise if you choose to change a control's settings.
3. Gain Control
If you haven't already, please read the getting started
section on page 6.
The gain knobs adjust the input sensitivity of the tuic
and line inputs. This allows signals from the outside
world to be adjusted to run through each channel at
optimal internal operating levels.
If the signal originates through the mic XLR jack,
there will he 0dB of gain with the knob fully down,
ramping to 60dB of gain fully
tip.
Through the
V4"
line input of Mnnels 1-20
(2"104\LZ4) and channel 1-28 3204VLZ4), there is 20
dB of attenuation fully down and 40 dB of gain fully up,
with unity gain "U" at 10:00.
Through the 1/4" line input of channels 21/22 and
23/24 (2404VLZ4) and 29/30 and 31/32 (3204VLZ4),
there is 20 dB of attenuation fully down and 20 dB of
gain fully up with unity gain "U" at 12:00.
This 20 dB of attenuation can be very handy when you
are inserting a hot signal, or when you want to add EQ
gain, or both. Without this "~irtu~l pad," there is more
chince of channel clipping.
24. Low Cut
All mono channels have a low-cut switch (often
referred to as a high-pass filter) that cuts bass
frequencies below 100 Hz at a rate of 18 dE per octave.
We recommend that you use low-cut on every
microphone application except kick drum, bass guitar,
or hassy synth patches. These aside, there isn't much
down there that you want to hear, and filtering it out
makes the low stuff you do want much more crisp and
tasty. Not only that, but low-cut can help reduce the
possibilit~ of feedback in live situations, and it helps
to conserve ampliflcr power.
Another way to consider low-cut's function
is that it actually adds flexibility during live
performances. With the addition of low-cut,
you can safely use low equalization on vocals. Many
times bass shelving EQ can really benefit voices.
Trouble is. adding low EQ also boosts stage rumble,
mic handling clunks and breath pops from way-down
low. Apply~ng low-cut removes all those problems,
so you can add low EQ without blowing your subwoofers.
25.
Pad (-20 dB) Switch
In most eases, the pad switch will be disengaged.
However, microphones and balanced line-level signals
that produce a higher output than usual may require
that the gain control [23~ is turned way down. If this is
the case, engage the pad switch to allow an additional
20 dB at the input to the inic preamnp. This prevents
overloading the microphone preamp and provides better
gain control. The pad only applies to flIt inputs, not the
1/4" TRS inputs.
GAIN
16
GAIN
17
GAIN
18
GAIN
19
GAIN
20
LINEGAIN
21
22
0: 0
-20d0 .40dB .20~
4001
r
LOW CUT
~
LOW CUT
100HZ
L___.__J
OFF BwIAX
2Q41 40dB
LOW CUT
I 00Hz
COMP
23
24
-a
20dB '40dB
LOW CLOT
100Hz
COMP
LINE GAIN
~0~
-,
_n._,.%.
(fl'~'
"-0-—a."
20
C
-to
1040 '4040
I
(DWCUT
000 Hz
COMP
I I
VLZ4
4.Rus