4
Connections
Amplifier connections to the MH-1075C-F are made on the rear panel via a Neutrik® NL4P Speakon™ connector supplied by the installer. This
4-conductor connector provides power to both the MF and HF sections of the MH-1075C-F. The standard configuration, as shipped from the QSC
factory, uses an internal passive crossover to permit bi-amp operation of the MH-1075C-F and the associated LF enclosure. In this mode, the MF/HF
crossover is connected to the 1+ and 1- terminals and the 2+ and 2- connections are not used. It is possible to use tri-amp mode by removing the rear
panel of the MH-1075C-F and setting the crossover switch to the tri-amp position. The MF connections use the 1+ and 1- terminals and the HF
connections use the 2+ and 2- terminals. Pre-made speakON cables using high grade, 4 conductor stranded wire are readily available from a number
of suppliers and is highly recommended.
NOTE!:
Maintain proper loudspeaker connection polarity throughout the entire system for maximum performance. Do not apply full
range signal to the MH-1075C-F All required signal processing must be done before the signal is applied to the loudspeaker.
Bi-amp / Tri-amp Operating Mode Selection
By default, the operating mode selector switch is set to bi-amp. You can leave it in the bi-amp mode, or
switch to the tri-amp, depending on your application setup.
Default Configuration
Bi-amp — When set to bi-amp
(Figure 2)
, the MH-1075C-F accepts mid-high frequency signals on one set
of inputs and uses an internal crossover network between the mid- and high-frequency drivers. The signal
applied to the mid-high loudspeaker assembly must not contain low-frequency content (below 200 Hz).
This mode uses 1+ and 1- of the NL4 speakON connector.
Optional Configuration
IMPORTANT!:
This configuration requires removal of the rear panel to access the crossover
mode switch.
Tri-amp — When set to tri-amp
(Figure 3)
, the MH-1075C-F accepts separate mid- and high-frequency
signals on two sets of inputs. The internal crossover network is bypassed and only the protective circuitry
for the HF driver remains. Each of the driver’s signals must have the appropriate signal processing
before operating. In this mode, the MF connects to 1+ and 1-, the HF connects to 2+ and 2- of the
NL4 speakOn connector
NOTE!:
Do not connect amplifiers directly to the driver inputs! Always use the input
NL4 speakOn connector.
— Figure 1 —
Bi-amp mode, Factory Configuration
MF/HF
No Connection
Input
1+
1-
2+
2-
Pinout
Pos
Neg
N/A
N/A
Optional Tri-amp mode, Reset Internal Mode Switch
MF
HF
Input
1+
1-
2+
2-
Pinout
Pos
Neg
Pos
Neg
— Figure 2 —
1-
1+
NL4
— Figure 3 —
2-
2+
1-
1+
NL4
