A 48 dB/octave crossover should be chosen if this choice is not practical. This crossover with the
steep slopes can be used with a crossover frequency 1/4 octave away from the loudspeaker
cutoff point.
Changing the crossover frequency
Frequency modules
The XM6 crossover network has a control on the front panel to change the crossover frequency.
The frequency is shown on a four digit LED numeric display on the front panel of the unit. The
range is 20 Hz to 4500 Hz, and the frequency can be changed in steps of about 5%. A total of
160 frequencies are thus available. This nice feature comes with a cost. The XM9, XM16 and
XM26 use frequency modules to change the crossover frequency. These low cost modules are
plugged into a connector in the unit. The power has to be shut off and the top cover of the unit
removed. The module for the XM9 has 4 resistors on it. The module for the XM16 has 8 resistors
and the module for the XM26 has 4 resistors and four capacitors. The XM9 requires two modules
and the XM16 and XM16 require four modules for each crossover frequency chosen. These
modules are available for most frequencies. The manuals for the individual units have formulas in
them to compute the value of the resistors and capacitors. When ordering replacement modules
only the desired frequencies need be specified.
In order to replace the frequency modules the top cover of the unit needs to be removed. Undo
the two screws on each side of the unit and lift the cover. Make sure the power to the unit is
turned off. Proceed as follows:
XM9
Each circuit board has one frequency module. The same module sets both the high pass
and the low pass crossover point. It is inserted in a socket. The frequency module has four
resistors on it. Replace each module with the new module.
© 2017 Marchand Electronics Inc. www.marchandelec.com.
4
Amp
Left
Satellite
C
r
o
s
s
o
v
e
r
Left High Out
Right Low Out
Right High Out
Right
Satellite
Common
Subwoofer
Left Low Out
P
r
e
a
m
p
Right In
Left In
Left Out
Right Out
Amp
Amp
Sum Switch up
Figure 3
Two-way system with common subwoofer. The two low pass channels are summed when the
sum mode is selected.
