Martin Audio EMX2A User Manual

CONTENTS (ENGLISH) Page No

1 INTRODUCTION 2
2 UNPACKING 2
3 MAINS CONNECTION 2
4 INPUT CONNECTIONS 3
5 OUTPUT CONNECTIONS 4
6 MODES OF OPERATION 4
7 SENSE INPUTS 5
8 HIGH FREQUENCY EQUALISATION 7
9 MONO SUB 7
10 LEVEL ADJUSTMENT (TRIM) 7
11 WARRANTY 7
12 TECHNICAL SPECIFICATIONS 8

Martin Audio – EMX2A System Controller

The Martin Experience

CONTENTS

<

>

PRINT

GUIDES

MARTIN AUDIO

LONDON

1 INTRODUCTION

Thank you for purchasing a Martin Audio EMX Series system controller.
EMX controllers are used to optimise the performance of Martin EM Series
loudspeaker systems in all modes of operation - whether full-range or with
additional sub-bass. The EMX2A is dedicated to the3-way EM186 full­range and the EM201 and EM251 sub-bass systems.

2 UNPACKING

Each Martin EMX controller is built to the highest standard and thoroughly
inspected before it leaves the factory. After unpacking the unit, examine it
carefully for any signs of transit damage and inform your dealer if any such
damage is found. It is suggested that you retain the original packaging so
that the unit can be repacked at a future date if necessary.

Please note that Martin Audio and its distributors cannot accept
responsibility for damage to any returned product through the use of non­approved packaging.

3 MAINS CONNECTION

The EMX2A is provided with an IEC 320 type mains receptacle. It is
supplied with a 2m mains lead terminated with a standard IEC 320 plug,
which must be connected as below:

GREEN/YELLOW - EARTH • BROWN - LIVE • BLUE - NEUTRAL
Mains voltage tolerance ± 10% on each setting.

Fuses type T semi delay 100-120V 500mA(L), 220-240V 250mA(L)

W

ARNING: The EMX2A controller must always be operated with the

mains safety earth connected.

Martin Audio – EMX2A System Controller

ENGLISH

2

This equipment must be earthed.

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

DO NOT EXPOSE TO RAIN

OR MOISTURE

It should not be necessary to remove any protective earth or signal cable
shield connections.

!

This equipment conforms to the requirements of the
EMC Directive 89/336/EEC, amended by 92/31/EEC
and 93/68/EEC and the requirements of the Low
Voltage Directive 73/23/EEC, amended by 93/68/EEC.

Standards Applied EMC Emission EN55103-1:1996

Immunity EN55103-2:1996

Electrical Safety EN60065:1998

CONTENTS

<

>

PRINT

GUIDES

To change the mains voltage, remove the rectangular fuse cap and replace
it so that the correct voltage is indicated by the arrow on the body of the
rectangle. The earth terminal on the IEC connector is permanently
connected to the metal casing. The unit is supplied with the 0V electronic
reference ground taken to the case via an internal ‘signal ground’ lead and
space receptacle, which inserts a ground lift resistor when in the ‘Earth Off’
position. To connect the 0V electronic reference direct to the chassis
ground, use a pair of pliers to pull off the space receptacle from the ‘Earth
Off’ position and push it onto the 0V spade terminal (marked Earth On, on
the PCB).

4 INPUT CONNECTIONS

EMX2A inputs are on female XLR type connectors and are electronically
balanced. Pin 1 is normally open circuit but may be linked to sig 0V or
chassis earth by inserting a link on the PCB. The signal is always applied
between Pin 2 (hot +) and Pin 3 (cold -).

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.

For either balanced or unbalanced operation, always connect the signal
between Pins 2 and 3. The input cable shield should be derived from the
equipment which is sourcing the input provided that normal safety
requirements are met (ie the mains earth is correctly connected).

Martin Audio – EMX2A System Controller

ENGLISH

3

1

2

3

1

2

3

2

1

3

2

1

3

Source

Source

Chassis
Grounded
Shield

Signal
Grounded
Shield

EMX2A

Input

EMX2A

Input

Ground
Lift
Resistor

Ground
Lift
Resistor

Fig. 1

CONTENTS

<

>

PRINT

GUIDES

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 full­range by means of an internal PCB mounted slide switch.

Martin Audio – EMX2A System Controller

ENGLISH

4

CONTENTS

<

>

PRINT

GUIDES

7 SENSE INPUTS

Sense Input Connections

Variable Jumper Positions (see table on page 6)

Martin Audio – EMX2A System Controller

ENGLISH

5

EMX2A
Sense
Inputs

1

+

1

-

Amplifier
Output

Sense Input Connections

Position 1 Position 2 Position 3 Position 4

INDICATES
JUMPER LINK
FITTED

CONTENTS

<

>

PRINT

GUIDES

Each EMX2A output has an associated limiter which provides momentary
gain reduction when that output signal level exceeds a preset threshold.
Internal PCB mounted jumper plugs J1 - J6 select the thresholds for the
particular EM Series loudspeaker system being used.

Note: As supplied by the factory, jumper links J1-J6 are each set in the
appropriate position for the EM186 full-range system and EM201 sub-bass
powered with the recommended rating below. Should amplifiers of higher
rating be used, the limiter positions shown in brackets should be used as
indicated by the table below to increase the associated limiter thresholds.

The higher recommended power amplifier setting should only be used by
experienced users to provide enhanced headroom on short duration peaks
and should not be used to push the system for a continuous higher sound
pressure level which will result in drive unit failure.

SYSTEM OUTPUT JUMPER POSITION AMPLIFIER

POWER
INTO 4 OHMS

EM186 LCH Bass J3 2 (3) 500 (700) watts

RCH Bass J4 2 (3) 500 (700) watts
LCH Mid/High J5 2 (3) 400 (550) watts
RCH Mid/High J6 2 (3) 400 (550) watts

EM201/251 LCH1 Sub J1 1 (2) 550 (900) watts

RCH2 Sub J2 1 (2) 550 (900) watts

Onset of limiting is indicated by front panel LED’s and determined by
sensing the actual voltage applied to the loudspeaker. The sense inputs on
the rear panel should be connected as shown in Fig 3. If no sense
connection is made or if the connection is broken at any time, the output
level will automatically be attenuated by 20dB and the limit LED for the
output concerned will light continuously to alert the operator.

Amplifier gain controls should normally be set at maximum. If a single
EMX2A output is used to drive several amplifier channels with different gain
settings, the sense input should be connected to the channel with the
highest setting.

WARNING: Connections to the EMX2A sense sockets should only be made
using approved shrouded plugs to comply with European safety standards.
No other plug is recommended or endorsed.

Martin Audio – EMX2A System Controller

ENGLISH

6

CONTENTS

<

>

PRINT

GUIDES

8 HIGH FREQUENCY EQUALISATION

System specific high frequency equalisation is available to tailor the power
response of EM Series high frequency devices. APCB mounted slide switch
switches the HF EQ in or out, depending on the particular EM Series
loudspeaker system in use.

Recommended switch settings are as follows:

SYSTEM HF EQ

EM186 IN
The EMX2A is supplied from the factory with the HF EQ switch in the IN

position.

9 MONO SUB

A jumper link within the EMX2A (J7) may be positioned to mono-sum the sub­bass signal. Amono left and right signal will then appear on both the sub out
XLR’s.

10 LEVEL ADJUSTMENT (TRIM)

The full-range output level is set at a nominal 0dB gain. To balance the
complete system, sub-bass levels can be adjusted by means of PCB
mounted trim controls accessed with a small screwdriver through the front of
the EMX2A.

11 WARRANTY

Martin Audio EMX2ASystem Controllers are warranted against manufacturing
defects in materials or craftsmanship over a period of 1 year from the date of
original purchase. During the warranty period Martin Audio will, at it's
discretion, either repair or replace products which prove to be defective
provided that the product is returned in its original packaging, shipping
prepaid, to an authorised Martin Audio service agent or distributor.

Martin Audio Ltd. cannot be held responsible for defects caused by
unauthorised modifications, improper use, negligence, exposure to inclement
weather conditions, act of God or accident, or any use of this product that is
not in accordance with the instructions provided by Martin Audio.
Martin Audio is not liable for consequential damages.

This warranty is exclusive and no other warranty is expressed or implied.
This warranty does not affect your statutory rights.

Martin Audio – EMX2A System Controller

ENGLISH

7

CONTENTS

<

>

PRINT

GUIDES

Martin Audio – EMX2A System Controller

ENGLISH

8

12 TECHNICAL SPECIFICATIONS

EMX2A

INPUTS (SIGNAL) 2 Electronically Balanced
IMPEDANCE 36K ohms (18K ohms per leg single ended)

CMRR 60dB 20Hz - 10KHz
CONNECTORS 3 Pin female XLR

INPUTS (SENSE) 6 Electronically Balanced
IMPEDANCE 36K ohms
CONNECTORS Shrouded 4mm sockets

OUTPUTS 6 Electronically Balanced
SOURCE IMPEDANCE 47 ohms

MIN LOAD IMPEDANCE 500 ohms
MAX OUTPUT +20dBu into 500 ohms limiter defeated
CONNECTORS 3 Pin Male XLR

FREQUENCY RESPONSE -3dB @ 25Hz 12dB/octave

-3dB @ 35KHz 12dB/octave
DISTORTION+NOISE 0.01%THD @ 2V output (limiters cancelled)
SIGNAL+NOISE/ >97dB @ 2V output 20Hz - 20KHz quasi peak

NOISE RATIO o/c input
LIMITERS Individual for each channel. With program

related attack times Ratio 20:1
INDICATORS 6 x Limit LED’s. Sub/Full Range LED’s
MAINS SUPPLY IEC mains connector with integral fuse holder
MAINS VOLTAGE Externally selectable on IEC inlet

100-120-220-240V AC, 50/60Hz.

Voltage tolerance on each setting ± 10%
MAINS FUSE 220-240V: -250mAType ‘T’ (L)

100-120V: -500mAType ‘T’ (L)
DIMENSIONS (W) 482mm x (H) 45mm x (D) 211mm

(W) 19ins x (H) 1.8ins x (D) 8.3ins
WEIGHT 3.5kg (7.7lbs)
SHIPPING DIMENSIONS (W) 530mm x (H) 120mm x (D) 310mm

(W) 21ins x (H) 4.7ins x (D) 12.2ins
SHIPPING WEIGHT 4.1kg (9lbs)
Due to our policy of continuous improvement all specifications are subject to change

without notice.

CONTENTS

<

>

PRINT

GUIDES

EMX2A System Controller

Century Point, Halifax Road, Cressex Business Park, High Wycombe, Buckinghamshire HP12 3SL, England.

Telephone: [phone] Facsimile: [phone]

Web: www.martin-audio.com E-mail: [e-mail]

The Martin Experience

Please Click here to
return to main menu

Please Click here to
visit our website

CONTENTS

<

>

PRINT

GUIDES

MARTIN AUDIO

LONDON

The Martin Experience

ENGLISH

EMX2A System Controller

User’s Guide

ISSUE 2

CONTENTS

<

PRINT

GUIDES

>

MARTIN AUDIO

LONDON