9
CONTOUR
Pushing in this switch engages a filter
that provides 3 dB of boost to the low and
high frequencies (below 100Hz and above
12kHz). This provides a punchy, crisp
sound for most live music applications. You
can experiment with this switch by leaving
it out for a while, then pushing it in to de-
termine which way sounds best for your
application. It is especially useful when lis-
tening at lower volumes, as it highlights the
bass like a Loudness switch, in addition to
boosting the highs.
LOW CUT
Pushing in this switch engages a low-cut
filter, which rolls off the low frequencies be-
low 75Hz. This is useful for minimizing
stage noise (rumble) and microphone han-
dling noise.
It is highly recommended
that you engage this
switch when using the
SRM450 as a stage moni-
tor. This allows the bass
amplifier to utilize its power for those fre-
quencies useful in stage monitor
applications.
LEVEL
This is used to adjust the signal level, go-
ing into the built-in power amplifiers, from
Off up to 40 dB of gain. Since the SRM450
incorporates Mackie’s world-class low-noise
mic preamp technology, you can connect ei-
ther a line-level or a microphone-level signal
to the input, and use this control to adjust
the level correctly.
There is no phantom
power for a microphone,
so you should use a
dynamic mic, or use a
condensor type if it has
its own battery power.
Follow the Quick Start guide on page 6
for setting the
LEVEL
control. For most ap-
plications, it will be in the NORMAL
position (12 o’clock) . If you have a particu-
larly high line-level signal connected to the
SRM450, you may need to turn the control
down to the
LINE
indication (9 o’clock). If
you have a low line-level or mic-level signal
connected, you may need to turn the
LEVEL
control up to the
MIC
indication
(3 o’clock).
SIGNAL PRESENT Indicator
This LED illuminates whenever there is
a signal present at the
INPUT
connector on
the rear panel. It senses the signal just prior
to the
LEVEL
control, so even if the
LEVEL
control is turned down, the
SIGNAL
PRESENT
indicator still works.
PEAK Indicator
When the signal levels at the amplifier
outputs approach clipping, a soft compres-
sion circuit is activated that reduces the
input signal. The
PEAK
LED lights when-
ever the compression circuit is active. At
this time, the SRM450 may reach sound
pressure levels of 120 dB or more.
It’s okay for the
PEAK
indicator to blink
occasionally, but if it blinks frequently or
continuously, either turn down the signal
level at the mixer or other signal source, or
turn down the SRM450’s
LEVEL
control.
Wear hearing protection
if you are close to the
SRM450 playing at high
levels.
INPUT Connector
This is a female XLR-type connector that
accepts a balanced or unbalanced mic- or
line-level signal.
THRU Connector
This is a male XLR-type connector that
produces exactly the same signal that is
connected to the
INPUT
jack. It can be a
balanced or unbalanced mic- or line-level
signal. Use it to daisy-chain several active
speakers together off the same signal
source.
ACCESSORY Plate
This removable plate provides access to
install future accessory modules.
