MACKIE CFX SERIES - Manual (Page 12)

12
CHANNEL STRIP FEATURES
Through a stereo channel’s stereo LINE IN
TRS inputs, there is 20 dB of attenuation fully
down and 20 dB of gain fully up, with a “
U”
(unity gain) mark at 12:00 (knob halfway up).
Having 20 dB of line-level attenuation can
be very handy when you are injecting a signal
that is very hot, when you want to add a lot of
EQ boost, or both. Without this “virtual pad,” it
would be very difficult to control the signal and
might lead to channel clipping.
ZERO LEVEL
This handy LED, which (we hope) you al-
ready read about in “QUICK START,” is triggered
to glow when it receives an audio signal at or
above 0 dBu.
If the LED is glowing, as opposed to flicker-
ing, turn the TRIM down. If the LED is
doing almost nothing, turn the TRIM up.
For a more accurate method of setting trim
levels, please see RUDE SOLO (page 15),
where a soloed signal will appear on the
mixer’s meters
.
LOW CUT
The LOW CUT switch, often referred to as a
High Pass Filter (depends on how you look at
it), cuts bass frequencies below 100Hz at a rate
of 18 dB per octave.
We recommend that you use LOW CUT on
every microphone application except kick
drum, bass guitar, or bass-heavy synth patches.
LOW CUT can also help reduce the possibility
of feedback in live situations and it helps to
conserve amplifier power.
AUX
These knobs tap a portion of each channel
signal and send it out, via the AUX SEND
jacks, to an external device for parallel effects
processing or stage monitoring.
AUX levels are controlled by these AUX knobs
and by the AUX MASTER SENDs . These are
more than mere effects and monitor sends:
they can be used to generate separate mixes
for recording or “mix-minuses” for broadcast.
Each AUX knob’s level ranges from off
through unity (the center detent position) on
up to 15 dB of extra gain (fully clockwise).
The line-level stereo channels’ AUX knobs
control a mono sum of the channel’s stereo sig-
nals. For instance, on the CFX•20, channel 17
(L) and 18 (R) mix together to feed that
channel’s
AUX send knobs.
PHANTOM POWER
Ha! We tricked you! The phantom power
switch is not located in the channel strip sec-
tion at all! It’s way over on the right side of the
mixer (see graphic on previous page). We’re
just mentioning it here since it applies to the
channels; specifically, what type of micro-
phones you have plugged into them.
Push in this switch to provide phantom
power to the XLR MIC input jacks. All of the
XLR mic inputs are capable of providing phan-
tom power. Phantom power is required to
operate most condenser microphones (some
condenser microphones are battery-powered).
The CFX Series provide +48VDC phantom pow-
ering on pins 2 and 3 of the XLR connectors.
If you have dynamic, ribbon, or tube mics
that do not require phantom power, leave the
PHANTOM POWER switch out. If you are us-
ing both condenser and dynamic mics, don’t
worry. Phantom power will not hurt most dy-
namic mics. Check the microphone’s user
manual if you’re not sure.
Caution: Turn all output
levels down before operat-
ing this switch to avoid the
possibility of a “pop” in
your speakers.
Connecting an external line-level device to an
XLR input connector with the phantom power
switched on could damage the device. We recom-
mend using the
LINE IN and STEREO LINE
IN jacks for connecting line-level signals.
TRIM
If you haven’t already, please read the “SET
THE LEVELS” portion of “QUICK START,” on
page 5.
TRIM adjusts the input sensitivity of the mic
and line inputs connected to the channels,
mono and stereo. This allows signals from the
outside world to be adjusted to optimal internal
operating levels.
If the signal originates through a mono
channel’s MIC XLR jack, there will be 6 dB
of gain with the knob fully down, ramping to 50
dB of gain fully up.
Through a mono channel’s LINE IN TRS
input, there is 15 dB of attenuation fully down
and 30 dB of gain fully up, with a “
U” (unity
gain) mark at 12:00 (knob halfway up).
1
3-4
1-2
MUTE
U
+15 O O
U
+15 O O
U
+15 O O
U
+15 O O
1
2
600
1.5k 150
8k 100
12k
HI
MID
FREQ
80Hz
LOW
EQ
U
+15 -15
U
+15 -15
U
+15 -15
ASSIGN
L R
PAN
dB
30
20
10
O O
40
50
5
5
U
60
10
SOLO
PFL
1
EFX
2
(INT)
EFX
1
(EXT)
PRE FADER
AUX
TRIM
LOW CUT
100 Hz
ZERO
LEVEL
M
IC GAIN
6 +50
U
-15dB +30dB
Mono Channel