Mackie PPM1012 ユーザーズマニュアル
16
PPM1012
PPM1012
23. GAIN CONTROL
If you haven’t already, please read the level-setting
procedure on page 3.
The gain knobs adjust the input sen-
sitivity of the mic and line inputs. This
allows signals from the outside world to
be adjusted to optimal internal operat-
ing levels.
allows signals from the outside world to
be adjusted to optimal internal operat-
ing levels.
If the signal originates through the
XLR jack of a mono channel (1 to 8), there will be 0 dB
of gain with the knob fully down, ramping to 50 dB of
gain fully up.
of gain with the knob fully down, ramping to 50 dB of
gain fully up.
Through the 1⁄4" input, there is 20 dB of attenuation
fully down and 30 dB of gain fully up (20 dB on ste-
reo channels), with unity gain at 12:00. This 20 dB of
attenuation can be very handy when you are inserting
a very hot signal, or when you want to add a lot of EQ
gain, or both. Without this “virtual pad,” this scenario
might lead to channel clipping and distortion.
reo channels), with unity gain at 12:00. This 20 dB of
attenuation can be very handy when you are inserting
a very hot signal, or when you want to add a lot of EQ
gain, or both. Without this “virtual pad,” this scenario
might lead to channel clipping and distortion.
Clipping occurs when the peaks of the audio
signal passing through the preamplifi er are
too high, and can no longer be amplifi ed in
a linear way. The audio signals reach a point
signal passing through the preamplifi er are
too high, and can no longer be amplifi ed in
a linear way. The audio signals reach a point
just below the preamp's supply voltages, and fl atten out.
This is rather like a tall pointed volcano suddenly blow-
ing its top, leaving behind a lower fl atter top (clipped)
while thousands of tons of molten rock and ashes are
blasted into the earth's atmosphere to cause a kind of
global winter for thousands of years, leading to the dis-
appearance of the dinosaurs and the appearance of jazz
drummers. Only not. Adjust the gain to prevent this.
This is rather like a tall pointed volcano suddenly blow-
ing its top, leaving behind a lower fl atter top (clipped)
while thousands of tons of molten rock and ashes are
blasted into the earth's atmosphere to cause a kind of
global winter for thousands of years, leading to the dis-
appearance of the dinosaurs and the appearance of jazz
drummers. Only not. Adjust the gain to prevent this.
24. LOW CUT (Channels 1–8 only)
The mono channels each have a low-cut switch, often
referred to as a high-pass fi lter (all depends on how you
look at it). When engaged, this cuts the bass frequen-
cies below 100 Hz at a rate of 18 dB per octave. The mic
and line inputs of channels 1–8 are affected.
look at it). When engaged, this cuts the bass frequen-
cies below 100 Hz at a rate of 18 dB per octave. The mic
and line inputs of channels 1–8 are affected.
We recommend that you use low-cut on every micro-
phone application except kick drum, bass guitar, or
bassy synth patches. These aside, there isn’t much down
there that you want to hear, and fi ltering it out makes
the low stuff you do want much more crisp and tasty.
Not only that, but low-cut can help reduce the possibili-
ty of feedback in live situations, and it helps to conserve
amplifi er power.
bassy synth patches. These aside, there isn’t much down
there that you want to hear, and fi ltering it out makes
the low stuff you do want much more crisp and tasty.
Not only that, but low-cut can help reduce the possibili-
ty of feedback in live situations, and it helps to conserve
amplifi er power.
Another way to consider low-cut’s function is that it
actually adds fl exibility during live performances. With
the addition of low-cut, you can safely use low equaliza-
tion on vocals. Many times, bass shelving EQ can really
benefi t voices. Trouble is, adding low EQ also boosts
stage rumble, mic handling clunks and breath pops
from way-down low. Applying low-cut removes all those
problems, so you can add low EQ without losing a woofer
out the window.
the addition of low-cut, you can safely use low equaliza-
tion on vocals. Many times, bass shelving EQ can really
benefi t voices. Trouble is, adding low EQ also boosts
stage rumble, mic handling clunks and breath pops
from way-down low. Applying low-cut removes all those
problems, so you can add low EQ without losing a woofer
out the window.
80Hz
LOW
MID
FREQ
R
L
U
GAIN
MI
C GAIN
0
+50
-20dB
+30dB
600
1.5k
150
8k
100
OFF
MAX
U
GAIN
MI
C GAIN
0
+50
-20dB
+30dB
U
GAIN
MI
C GAIN
0
+50
-20dB
+30dB
U
GAIN
MI
C GAIN
0
+50
-20dB
+30dB
U
GAIN
MI
C GAIN
0
+50
-20dB
+30dB
1
2
3
4
5
SOLO
OL
+10
0
-20
SOLO
OL
+10
0
-20
1
2
3
4
5
EQ
OFF
MAX
OFF
MAX
OFF
MAX
OFF
MAX
12kHz
HI
PAN
AUX
SEND
COMP
COMP
COMP
COMP
COMP
MON
1
MON
2
FX
1
FX
2
U
+15
O
O
U
+15
O
O
U
+15
O
O
U
+15
O
O
-15
U
+15
-15
U
+15
-15
U
+15
80Hz
LOW
MID
FREQ
R
L
600
1.5k
150
8k
100
EQ
12kHz
HI
PAN
AUX
SEND
MON
1
MON
2
FX
1
FX
2
U
+15
O
O
U
+15
O
O
U
+15
O
O
U
+15
O
O
-15
U
+15
-15
U
+15
-15
U
+15
80Hz
LOW
MID
FREQ
R
L
600
1.5k
150
8k
100
EQ
12kHz
HI
PAN
AUX
SEND
MON
1
MON
2
FX
1
FX
2
U
+15
O
O
U
+15
O
O
U
+15
O
O
U
+15
O
O
-15
U
+15
-15
U
+15
-15
U
+15
80Hz
LOW
MID
FREQ
R
L
600
1.5k
150
8k
100
EQ
12kHz
HI
PAN
AUX
SEND
MON
1
MON
2
FX
1
FX
2
U
+15
O
O
U
+15
O
O
U
+15
O
O
U
+15
O
O
-15
U
+15
-15
U
+15
-15
U
+15
80Hz
LOW
MID
FREQ
R
L
600
1.5k
150
8k
100
EQ
12kHz
HI
PAN
AUX
SEND
MON
1
MON
2
FX
1
FX
2
U
+15
O
O
U
+15
O
O
U
+15
O
O
U
+15
O
O
-15
U
+15
-15
U
+15
-15
U
+15
LOW CUT
100 Hz
LOW CUT
100 Hz
LOW CUT
100 Hz
LOW CUT
100 Hz
LOW CUT
100 Hz
dB
10
O
O
5
5
U
dB
30
20
10
O
O
40
50
50
5
5
U
60
SOLO
OL
+10
0
-20
dB
30
20
10
O
O
40
50
50
5
5
U
60
SOLO
OL
+10
0
-20
dB
30
20
10
O
O
40
50
50
5
5
U
60
SOLO
OL
+10
0
-20
dB
30
20
10
O
O
40
50
50
5
5
U
60
30
20
40
50
60
50
60
10
10
10
10
10
1+
1
1
1+
1
1
U
GAIN
MI
C GAIN
0
+50
-20dB
+30dB
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