9
CHAPTER 2
The M2D and M2D-Sub loudspeakers use sophisticated
amplication and protection circuitry to produce
consistent and predictable results in any system design.
This chapter will help you understand and harness the
power of the M2D and M2D-Sub amplier and audio
systems.
The rear panels of the M2D and M2D-Sub loudspeakers
(Figures 2.1 and 2.2) provide AC connection, audio input,
loop out and an interface to the RMS communications
module.
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Figure 2.1. The user panel of the M2D loudspeaker
THISAPPARATUSMUSTBE EARTHED.
REFERSERVICINGTOQUALIFIED PERSONNEL.
UNDREPARATURNURDURCH ELEKTROF�CHKRAFTE
95-125V~ 208-235V~
INTERNESNESONTAUTORISEES QU'AU
Auto-VoltageSelect
PERSONNELTECHNIQUEQUALIFI…
NOOPERATORSERVICEABLEPARTS INSIDE.
Turnon165V~ Turn off 264V~
Turnon85V~ Turnoff134V~
OperationalVoltageRange:
1400WRMSMAX1400W RMS MAX
50-60Hz 50-60Hz
ENTRETIENETREPARATIONS
Wink
Service
Activity
Reset
U.K.WARNING:
ATTENTION:
THISPRODUCTMUST BE GROUNDED
Thissurfacemayreach high tempuratures white in use.
Toensureproperoperation, allow at least 6 inches
AUTHORIZADOAPERSONALT…CNICO CALIFICO
Toreducetherisk of electric shock do not remove cover.
GEH�USENICHTOFFENEWARTUNG
ACCESOINTERNOSOLO
Toreducetherisk of fire or electric shock
Referservicingtoqualified personnel.
Nooperatororserviceable parts inside.
donotexposethis appliance to rain or moisture.
clearancefromthissurface and adequate ventilation.
ATENCI”N:
ACHTUNG:
WARNINGS:
MeyerSound,Berkeley,CA USA
Figure 2.2. The user panel of the M2D-Sub loudspeaker

AUDIO INPUT

The M2D and M2D-Sub loudspeakers present a 10 kOhm
balanced input impedance to a three-pin XLR connector
with the following connectors:
Pin 1 — 220 kOhm to chassis and earth ground (ESD
clamped)
Pin 2 — Signal ( + )
Pin 3 — Signal ( - )
Case — Earth (AC) ground and chassis
Pins 2 and 3 carry the input as a differential signal; pin
2 is hot relative to pin 3, resulting in a positive pressure
wave when a positive signal is applied to pin 2. Pin 1 is
connected to earth through a 220 kOhm, 1000 pF, 15 V
clamp network. This ingenious circuit provides virtual
ground lift for audio frequencies, while allowing unwanted
signals to bleed to ground.
Use standard audio cables with XLR connectors for
balanced signal sources. Make sure that pin 1 (shield) is
always connected on both ends of the cable. Telescoping
grounding schemes are not recommended.
CAUTION: Ensure that all cabling carrying
signals to M2D or M2D-Sub loudspeakers
in an array is wired correctly: Pin 1 to Pin 1, Pin 2
to Pin 2, and so forth, to prevent the polarity from
being reversed. Any number of loudspeakers —
even one in the array — with reversed polarity will
result in severe degradation in frequency response
and coverage.
Audio signals can be daisy-chained using the loop output
connector on the user panel (Figure 2.3). A single source
can drive multiple M2D or M2D-Sub loudspeakers with a
paralleled input loop, creating an unbuffered hard-wired
loop connection.
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THISAPPARATUS MUST BE EARTHED.
REFERSERVICING TO QUALIFIEDPERSONNEL.
UNDREPARATUR NUR DURCH ELEKTROF�CHKRAFTE
95-125V~ 208-235V~
INTERNESNE SONT AUTORISEES QU'AU
Auto-VoltageSelect
PERSONNELTECHNIQUE QUALIFI…
NOOPERATOR SERVICEABLE PARTSINSIDE.
Turnon 165V~ Turnoff264V~
Turnon 85V~ Turn off 134V~
OperationalVoltageRange:
1400WRMS MAX1400W RMS MAX
50-60Hz 50-60Hz
ENTRETIENETREPARATIONS
Wink
Service
Activity
Reset
U.K.WARNING:
ATTENTION:
THISPRODUCT MUST BE GROUNDED
Thissurface may reach high tempuratures white in use.
Toensure proper operation, allow at least 6 inches
AUTHORIZADOA PERSONAL T…CNICOCALIFICO
Toreduce the risk of electric shock do not remove cover.
GEH�USENICHT OFFENE WARTUNG
ACCESOINTERNO SOLO
Toreduce the risk of fire or electric shock
Referservicing to qualified personnel.
Nooperator or serviceable parts inside.
donot expose this appliance to rain or moisture.
clearancefrom this surface and adequate ventilation.
ATENCI”N:
ACHTUNG:
WARNINGS:
MeyerSound, Berkeley,CA USA
Figure 2.3. M2D and M2D-Sub user panel audio input connectors
CHAPTER 2: AMPLIFICATION AND AUDIO