5
OUTPUT CONNECTIONS
EMX2A outputs are electronically balanced auto compensating via male
XLR type connectors. Pin 1 is the (ground) connection and the signal
appears between Pins 2 and 3.
Always use 2-core + screen ‘balanced’ type signal leads, even for
unbalanced circuits. The screen should be regarded as separate from the
signal return, even if they are connected together at one end of the line.
This is to keep the screen a true screen so that no signal return currents
flow through it which can induce signals in adjacent cables.
For unbalanced use, having decided which pin is ‘hot’ (see above), connect
the ‘cold’ pin and (Pin 1) together. The internal signal ground lead should
be placed in the earth off position at the EMX2A outputs which permit the
amplifier to be locally grounded (as required for safety reasons) without
causing a hum loop. If the signal is merely taken between either Pin 2 or 3
and Pin 1, a level loss and signal degradation will occur.
For balanced operation, the screen should be connected to ground at the
amplifier end. To eliminate ground current loops, it can be lifted at the
EMX2A output, provided normal safety requirements have been met (ie the
mains earths are correctly connected).
The power ratings of amplifiers connected to EMX Series controllers should
lie within the range recommended for the EM Series loudspeaker system
being driven. Please refer to the section on amplification in the EM Series
user’s guide for further information.
6
MODES OF OPERATION
The EMX2A is a 2-channel system controller which is recommended for
use with the Martin Audio EM186 3-way loudspeaker system used either
full-range or within additional Martin EM201 or EM251 sub-bass systems.
In its full-range mode, the EMX2A is a 2-in/4-out device providing full
system equalisation and 650Hz electronic crossover functions to drive the
separate low and mid/high sections of bi-amplified EM186 systems. It also
features loudspeaker protection using limiters activated by the true voltages
applied to the loudspeaker.
In its sub-bass mode, it is reconfigured automatically as a 2-in/6-out 120Hz
and 650Hz electronic crossover which provides outputs for the sub-bass,
low and mid/high sections. All six outputs are provided with sense inputs to
monitor the actual loudspeaker drive voltages.
Sub-bass or full-range mode of operation is selected by a push switch on
the front panel. It is important to note that the sub-bass outputs are always
present at the sub-bass output connector, even when full-range operation is
selected for the main system.
The EMX2A full-range mode normally provides separate outputs to the low
and mid/high sections of the EM186 bi-amplified systems. For special
applications, the EMX2A low frequency outputs can be switched to full-
range by means of an internal PCB mounted slide switch.
Martin Audio – EMX2A System Controller
E
NGLISH
4
CONTENTS
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GUIDES
