
2
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M3D
™
Line Array Meyer Sound Laboratories Inc
Information and specifications are applicable as of the 
date of printing. Updates and supplementary information 
are posted on the Meyer Sound web site at:
http://www.meyersound.com
or you may contact Meyer Sound Technical Support at:
Tel: 510.486.1166
fax: 510.486.8356
email: techsupport@meyersound.com
AC P
OWER
When AC power is applied to the M3D or M3D-Sub, the 
Intelligent AC™ supply automatically selects the correct 
operating voltage, allowing the loudspeakers to be used 
internationally without manually setting voltage 
switches. The Intelligent AC supply performs the 
following protective functions to compensate for hostile 
conditions on the AC mains:
■
suppresses high-voltage transients up to several 
kilovolts
■
filters common mode and difference mode radio 
frequencies (EMI)
■
sustains operation temporarily during low-voltage 
periods
■
provides soft-start power-up, which eliminates high 
inrush current
Refer to Table 2 on page 20 of Appendix A for a 
complete listing of power requirements and 
specifications for the M3D Line Array, or Table 3 on 
page 23 for the power requirements and specifications 
for the M3D-Sub Directional Subwoofer.
The M3D or M3D-Sub can withstand continuous voltages 
up to 275 V and allows any combination of voltage to 
GND (that is neutral-line-ground or line-line-ground). 
The M3D or M3D-Sub uses a NEMA L6-20P, an IEC 309 or 
a multipin VEAM male power connector and satisfies 
worldwide product safety standards.
AC Power Distribution
All amplifier modules and the rest of the audio equipment 
connected to it (mixing consoles, processors, etc.) must 
be connected to the AC power distribution in a proper 
way, preserving AC line polarity and connecting earth 
ground such that all grounding points are connected to a 
single node or common point using the same cable gauge 
as the neutral and line(s) cables. 
Bad grounding connections between speakers and the 
rest of the audio system may produce noise, hum and/or 
serious damage to the input/output stages in the 
system’s electronic equipment.
Figure 3 shows a sample three-phase AC distribution 
system, with the load between speakers distributed 
among the three phases and all of the loudspeakers 
connected to common neutral and earth ground points.
Voltage Requirements
The M3D or M3D-Sub operates safely and without audio 
discontinuity if the AC voltage stays within either of two 
operating windows: 85-134 V or 165-264 V, at 50 or 
60 Hz. Refer to Table 2 on page 20 for the M3D or Table 3 
on page 23 for the M3D-Sub for detailed AC voltage 
requirements.
After applying AC power, the proper operating voltage is 
automatically selected, but the system is muted. During 
the next three seconds the following events occur:
1. The primary fans turn on.
2. The main power supply slowly ramps on.
3. The green 
Active
 LED on the user panel lights up, 
indicating that the system is enabled and ready to 
pass audio signals.
!
CAUTION:
Continuous voltages higher than 
275 V can damage the unit.
!
CAUTION:
Before applying AC to any Meyer 
Sound self-powered speaker, be sure that the 
voltage potential difference between neutral 
and earth ground is less than 5 VAC.
Figure 3.
AC power distribution block diagram
Line 1 Line 2 Line 3 Neutral
Earth Ground