6
For versatility and increased headroom, some users
may choose to use an active electronic crossover /
processor, such as the Fender PCN-2 or PCN-4, with
the system. The electronic crossover takes the place
of the internal crossover of the speaker system. The
"Normal / Bi-Amp" switch on the back of the cabinet
must be set to the "Bi-Amp" position. Always check
to ensure the internal/external crossover switch
which selects passive or biamp operation is in the
correct position prior to use. Failure to do so may
damage the speakers. A typical set-up of a bi-amp
configuration is shown at right.
For those situations requiring a subwoofer, Mk III
loudspeakers can still be used if a three-way electronic
crossover is used. An example of this configuration is
shown on the next page.
It is strongly recommended that a fourth-order
"Linkwitz-Riley" or a digital FIR fourth-order active
crossover be used. The crossover frequency, for both
the 1225 Mk III / 1226 Mk III, should be set at
approximately 2200 Hz, the 1211 Mk III should be set
at approximately 1200 Hz. Since the output sensitivity
of the compression driver is higher than that of the
woofer, the high frequency output of the system must
be decreased at either the crossover (if such a control
is provided) or at the power amplifier(s) that are used
for the high frequencies.
CAUTION: Be sure to connect the high frequencies
and low frequencies to their correct inputs
indicated on the back of the speaker cabinets.
Mk III Series cabinets are covered in a
tough, black indoor/outdoor synthetic
carpet for long life and lasting good
looks. To clean the carpet covering, use
a sponge and a light soapy water
solution to wipe away any smudges or
dirt. For stubborn stains, a slightly more concentrated
soapy solution or carpet shampoo with a brush may
be used. Avoid spilling liquids on the input panel, grille
and speakers.
BI-AMP OPERATION
CARPET COVERING CARE
MONITOR
OUT
MAIN
OUT
UNPOWERED MIXER
IN
LOW
OUT
HIGH
OUT
A In
A Out
SPL-9000 POWER AMP
PCN-2 ELECTRONIC CROSSOVER
B Out
B In
SWITCHES
SET TO
EXTERNAL
CROSSOVER
Speakers operated in a bi-amp configuration
Mk III
Cabinet
Hi
Low
Hi
Low
Mk III
Cabinet