Filter
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14
In order to match the output bandwidth with
your particular speaker system, the M•800 am-
plifier has a tunable
LOW CUT FILTER.
The
frequencies are clearly marked along the knob’s
travel:
• Fully counterclockwise, the frequency is be-
low 10Hz, effectively bypassing the filter.
• Center detent is
35Hz
, labeled
TYPICAL,
since few woofers actually go below that.
• 3/4 of the way up is labeled
STAGE
MONITOR, 100Hz,
perfect for, well,
stage monitors (they seldom reproduce
below 100Hz; besides, it prevents low fre-
quency “leakage” into the house).
• Fully clockwise is labeled
170Hz.
So, grab your woofer’s spec sheet and find
the low roll-off spec. Then set the M•800’s
LOW CUT FILTER
at the same frequency.
If you do this correctly (and make sure the
meters are happy), you’ll never again see your
woofer moving sporadically without audible
signal. Your system will play louder and
cleaner, and you may never blow another
woofer again!
CH
1
1
CHANNEL
CH
2
SPEAKER OUTPUTS
+
––
+
MONO
BRIDGE
BAL/UNBAL
MONO
BRIDGE
OFFON OFFON OFFON
120 VAC 60 Hz
1500 WATTS
CONSTANT DIRECTIVITY
HORN EQ /AIR EQ
LOW CUT
FILTER
170 Hz
OFF
4.5k Hz
6k Hz
2k Hz
AIR EQ
100 Hz
STAGE
MONITOR
TYPICAL
35 Hz
TYPICAL
TYPICAL
TYPICAL
TYPICAL
STEREO
(MONO BRIDGE)
800 WATTS
4 OHM LOAD MIN.
400 WATTS CH
2 OHMS LOAD MIN.
THRU
LOW CUT
FILTER
INPUT
INPUT
THRU
170 Hz
OFF
4.5k Hz
6k Hz
2k Hz
AIR EQ
TYPICAL
35 Hz
CONSTANT DIRECTIVITY
HORN EQ /AIR EQ
CHANNEL
2
BAL/UNBAL
AMP MODE
LIMITER
SERIAL NUMBER
MANUFACTURING DATE
RISK OF ELECTRIC SHOCK
DO NOT OPEN
WARNING:
TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT
EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE. DO NOT REMOVE COVER.
NO USER SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL.
CAUTION
AVIS:
RISQUE DE CHOC ELECTRIQUE — NE PAS OUVRIR
THE FOLLOWING ARE TRADEMARKS/REGISTERED TRADEMARKS OF MACKIE DESIGN INC.: "MACKIE", "FR SERIES", & THE "RUNNING MAN" FIGURE
CONCEIVED, DESIGNED, AND MANUFACTURED BY MACKIE DESIGNS INC • WOODINVILLE
WA • 98072 • USA • MADE IN USA • PATENTS PENDING • COPYRIGHT ©1999
100 Hz
STAGE
MONITOR
Low Cut Filter Frequency Response
You can use the
THRU
jack
as an input, if necessary,
since it’s wired in parallel
with the other input con-
nectors.
You can also use the
1/4" TRS
INPUT
jacks as
THRU
jacks. Simply
connect the 1/4" TRS
INPUT
jacks on the first
amplifier to the TRS 1/4"
INPUT
jacks on the
second amplifier using 3-conductor shielded
cables with TRS plugs on both ends.
Warning: If you are using a
balanced input to the first
amp, do not use TS unbal-
anced connections to feed
other amplifiers. This will
unbalance the input con-
nections of your first amp by grounding pin 3.
LOW CUT FILTER
Every woofer has frequency response speci-
fications. It’s usually expressed in Hertz (or
cycles per second), like “40Hz–300Hz.” The
“40Hz” refers to the low-frequency point (usu-
ally, but not always) where the speaker’s
output drops by 3 dB, and will “roll off” com-
pletely as the frequency goes down. There is no
point in sending a woofer any frequencies it
can’t reproduce — you can’t hear it, and worse
yet, it’s a waste of amplifier power that can be
better used reproducing frequencies you can hear.
10
Hz
1
Hz
100
Hz
1k
Hz
10k
Hz
20k
Hz
–15
dB
–10
dB
–5
dB
0
dB
5
dB
LCFil
Level, dB
Fre
q
uenc
y
, Hz
LOW CUT
FILTER
170 Hz
OFF
100 Hz
STAGE
MONITOR
TYPICAL
35 Hz