Martin Audio WX3A - SCHEMATICS User manual

CONTENTS (ENGLISH) Page No
1 INTRODUCTION 2
2 UNPACKING 3
3 MAINS CONNECTION 3
4 CONNECTIONS 4
4.1 Input Connections 4
4.2 Output Connections 5
5 INITIAL SETTINGS 6
6 WX3A SYSTEM CONFIGURATIONS WITH PLUG-IN BOARDS 6
6.1 WX3A / W2 - Active W2 Configuration (Stereo) 7
6.2 WX3A / W3 - W3 Configuration (Stereo) 7
6.3 WX3A - Sub Bass and Full Range
/ High Pass Configuration (Stereo) 8
6.4 W1, W2, W3 Passive Operation
Using WX3ASF Card (Stereo) 9
6.5 W1, W2, W3 Passive with Sub Bass Operation
Using WX3ASF (Stereo) 9
6.6 Mono Sub Bass 10
6.7 Active W2/W3 with Sub Bass Operation
Using WX3AW2LF Card or WX3AW3LF Card (Stereo) 10
6.8 WX3A W2 Mono With Sub Bass Configuration 12
6.9 WX3A W3 Mono With Sub Bass Configuration 12
7 LEVELS 13
8 LIMITERS 13
9 WARRANTY 14
10 TECHNICAL SPECIFICATIONS 15
Martin Audio – WX3A System Controller
MARTIN AUDIO
LONDON
The Martin Experience
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1 INTRODUCTION
Thank you for purchasing a Martin Audio WX3A System Controller. The
WX3A is used to optimise the performance of Wavefront Series
loudspeakers.
Crossover functions, relative output levels and phase adjustments are all
preset for a given Wavefront system by means of a dedicated system-
specific plug-in board.
A user adjustable low-distortion limiter is fitted to each band.
Each band features output level adjustment, from -ve infinity to +6dB
relative to its nominal level. All inputs and outputs are electronically
balanced. This feature in conjunction with extremely low system noise
makes the WX3A ideal for theatre and other critical applications.
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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
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2 UNPACKING
Each Martin Audio WX3A 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 non-
approved packaging.
3 MAINS CONNECTION
The WX3A 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)
WARNING: The WX3A controller must always be operated with the
mains safety earth connected.
To change the mains voltage, remove the rectangular fuse cap and replace
it so that the arrow on the body of the rectangle indicates the correct
voltage. 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).
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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.
!
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4 CONNECTIONS
4.1 Input Connections
WX3A 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 (see Fig 1). The signal is
always applied between Pin 2 (hot +) and Pin 3 (cold -).
Fig. 1
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
equipment which is sourcing the input provided that normal safety
requirements are met (ie the mains earth is correctly connected). See Fig 2.
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/link for pin 1 chassis/earth
\link for pin 1 signal 0V
/\ No link for pin 1 open circuit
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Fig. 2
4.2 Output Connections
The WX3A 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’, connect the ‘cold’
pin and (Pin 1) together. The internal signal ground lead should be placed
in the earth off position at the WX3A outputs which allows 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.
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1
23
1
23
2
13
2
13
Source
Source
Chassis
Grounded
Shield
Signal
G
rounded
Shield
WX3A
Input
WX3A
Input
Ground
Lift
Resistor
Ground
Lift
Resistor
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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
WX3A output, provided normal safety requirements have been met (i.e. the
mains earths are correctly connected). See Fig 3.
Fig. 3
5 INITIAL SETTINGS
WX3A units are supplied with the adjustments set as follows:
Mains Voltage - 240V
Ground Switch - ON
Limiter Threshold - 2V setting
Plug-in Board - System specific
6 WX3A SYSTEM CONFIGURATIONS WITH PLUG-IN BOARDS
The WX3A used in conjunction with a plug-in board becomes a dedicated
system controller. Depending on the plug-in system-specific board, the
WX3A is automatically configured either as a stereo 2-way or mono 3-way
device for a specific Wavefront system.
Each plug-in board dictates a system-specific crossover function,
equalisation and in some cases group delay.
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1
23
2
13
Chassis
Grounded
Shield
Signal
Grounded
Shield 1
23
2
13
WX3A Output
WX3A Output Amplifier Input
Amplifier Input
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Mounted on each plug-in board are jumper links. The links determine
various low frequency equalisation (LF EQ) options. They are set by the
user according to the application of the system. The various options
concerning LF EQ are outlined in the following. These should be examined
carefully, especially when using sub-bass in a system.
6.1 WX3A / W2 - Active W2 Configuration (Stereo)
The WX3AW2LF board is used to control the W2 when operated as an
active 2-way system (see Fig 4). Active crossover frequency (1500Hz),
relative output levels, driver alignment and equalisation are all pre-set for
the W2 system. LF EQ circuitry gives 6dB of boost at 65Hz for full-range
operation.
6.2 WX3A / W3 - W3 Configuration (Stereo)
The WX3AW3LF board is used to control the W3 loudspeaker system (see
Fig 5). Active crossover frequency (650Hz), relative output levels, driver
alignment and equalisation are all pre-set for the W3 system. LF EQ
circuitry gives 6dB of boost at 65Hz for full-range operation.
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W2 ACTIVE
LEFT
INPUT RIGHT
INPUT
LF MF/HF LF MF/HF
W2 ACTIVE
W3 ACTIVE
LEFT
INPUT RIGHT
INPUT
LF MF/HF LF MF/HF
W3 ACTIVE
Fig 4. W2 Active Configuration using WX3AW2LF Card.
Fig 5. W3 Active Configuration using WX3AW3LF Card.
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6.3 WX3A - Sub Bass and Full Range/High Pass
Configuration (Stereo)
The WX3ASF plug-in board is used to control the W1, passive W2 and
passive W3 when operating either as stand-alone full-range systems or with
additional WS2 sub-bass enclosures.
It is also used to provide the outputs for other WX3A controllers configured
to drive active W2 and W3 systems used in stereo with WS2 sub-bass
enclosures.
PCB mounted jumper links on the plug-in board select various alignment
options for the full-range/high pass outputs (Bands 2 and 4). See Fig 6.
Fig. 6
If full-range mode (1) is selected, +6dB of low frequency boost at 65Hz is
applied to the full-range outputs (Bands 2 & 4).
If 100Hz high-pass crossover mode (2) is selected, the full-range outputs
are re-configured as 100Hz high-pass outputs.
In Overlap Mode (3), the sub-bass and full-range enclosures are allowed to
overlap and 3dB of LF boost is applied to the full-range enclosure. This
can be useful when the full-range systems are flown some distance from
the sub-bass. This mode allows some low frequency energy to be
reproduced by the flown loudspeakers without using up as much headroom
as would be required if the full-range +6dB low frequency boost were
applied.
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Mode 1
Mode 2
Mode 3
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Plug-in board jumper link positions are as follows:
Jumper Position Jumper Position
Mode (1), Full Range J4/J5 B J1/J7 OUT
J3/J6 A J2/J8 OUT
Mode (2), 100Hz high-pass J4/J5 A J1/J7 IN
J3/J6 B J2/J8 IN
Mode (3), Overlap J4/J5 B J1/J7 IN
J3/J6 A J2/J8 IN
6.4 W1,W2,W3 Passive Operation Using WX3ASF Card (Stereo)
A WX3A controller is used to provide LF equalisation and limiter functions
for stand-alone W1, W2 and passive W3 systems operated full-range (see
Fig 7). In this instance the W1, W2 and W3 should be driven from Bands 2
and 4 set to operate in full-range Mode (1) (see Section 6.3).
6.5 W1,W2,W3 Passive with Sub Bass Operation
Using WX3ASF (Stereo)
The WX3ASF may also be used to drive a sub-bass system to augment the
W1, W2 and passive W3 systems (see Fig 8). The WX3A is normally
operated in 100Hz high-pass/crossover Mode (2) (see Section 6.3) for this
configuration, although it may be operated in Overlap Mode (3) if overlap is
required for flown systems. Full-range Mode (1) should only be used with
care, in special cases where distant flown systems are required to run full-
range. Some cancellation may occur if the W1, W2 and W3 are located in
close proximity to the sub-bass enclosure. However, this cancellation may
simply be resolved by reversing the phase of the W1, W2 or W3.
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LEFT
INPUT RIGHT
INPUT
NOT
USED F.R. NOT
USED F.R.
W2 PASSIVE
W3 PASSIVE
W1 W2 PASSIVE
W3 PASSIVE
W1
Fig 7. W1, W2 or W3 Passive operation using WX3ASF Card
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6.6 Mono Sub Bass
J9 on the WX3ASF Card can be used to mono sum channels 1 and 3.
6.7 Active W2/W3 with Sub Bass Operation Using
WX3AW2LF Card or WX3AW3LF Card (Stereo)
An additional controller fitted with a WX3ASF card may be used to drive a
sub-bass system to augment stereo W2 and W3 systems and their
controllers (see Fig 9).
In this set-up, the LF EQ of the WX3AW2LF or WX3AW3LF cards on Bands
1 & 3 should be switched out. This is achieved by moving jumper links
J1 –J2 on the card from the IN position to the OUT position (see Fig 9A)
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LEFT
INPUT RIGHT
INPUT
SUB F.R.
or H.P. SUB
W2 PASSIVE
W3 PASSIVE
W1 W2 PASSIVE
W3 PASSIVE
W1
F.R.
or H.P.
WS2A WS2A
W2 ACTIVE
W3 ACTIVE
WS2A
W2 ACTIVE
W3 ACTIVE
WS2A
LF
(EQ Defeat) LF
(EQ Defeat)
MF/HF MF/HF
W2 orW3
(Limiter
Cancel)
W2 orW3
(Limiter
Cancel)
SUB SUB
LEFT
INPUT RIGHT
INPUT
WX3AW2LF Card
or
WX3AW3LF Card
WX3ASF Card
Fig 8. W1, W2 or W3 Passive operation with Sub Bass using WX3ASF Card
Fig 9. Normal operation for augmenting Stereo W2/W3 Active with Sub Bass
J1 J2 J1 J2
IN IN OUT OUT
L . F . EQ L . F . EQ
Fig 9A.
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The limiters on the high-pass outputs of the WX3A driving the W2’s or W3’s
should also be defeated to prevent them operating in advance of following
units. To defeat the limiters on Bands 2 & 4, move jumper links J2 and J4
on the main circuit board to the left position. Please refer to Section on
limiters for further information.
The WX3ASF is normally operated in 100Hz high-pass/crossover mode (2)
(see Section 6.3) for this configuration, although it may be operated in
overlap mode (3) if overlap is required for flown systems.
Full-range mode (1) should only be used with care, in special cases where
distant flown systems are required to run full-range. Some cancellation
may occur if the W3/W2 are used in close proximity to the sub-bass
enclosure. However, this cancellation may be resolved by simply reversing
the phase of the W2 or W3.
For special effects applications, instead of the normal method of feeding
the high-pass outputs of the WX3ASF controller to a WX3A controller (as
shown in Fig 10), the WX3ASF controller may be connected in parallel as
an effects bandpass filter. The input to the sub-bass controller can either
be connected to the main left/right signal (parallel inputs) or may be fed
from a separate input signal. The W2 and W3 are left to run full-range (see
Sections 6.1/6.2).
In this parallel configuration it should be noted that, because the effect of
LF EQ circuit in the WX3/W2 (or W3) is still present in the full-range output,
some LF cancellation might occur. This may be especially noticeable if the
full-range systems are used in close proximity to the sub-bass enclosures.
LF cancellation due to this effect may simply be resolved by reversing the
phase of the W2 or W3.
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W2 ACTIVE
W3 ACTIVE
WS2A
WX3ASF
WX3AW2LF
or
WX3AW3LF
W2 ACTIVE
W3 ACTIVE
WS2A
NOT
USED
SUB NOT
USED
SUB
LEFT
INPUT RIGHT
INPUT
MF/HF MF/HF
LF
LF
Fig 10. Parallel operation for augmenting Stereo W2/W3 Active with Sub Bass
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6.8 WX3A W2 Mono With Sub Bass Configuration
The W2 Active + Sub mono configuration is used to control a single
channel active W2 system when used with a sub-bass (see Fig 11). Active
crossover frequencies (100Hz, 1500Hz), relative output levels, driver
alignment and equalisation are all pre-set for the W2 system plus sub-bass.
6.9 WX3A W3 Mono With Sub Bass Configuration
The W3 Active + Sub mono configuration is used to control a single
channel active W3 system when used with a sub-bass (see Fig 12). Active
crossover frequencies (100Hz, 650Hz), relative output levels, driver
alignment and equalisation are all pre-set for the W3 system plus sub-bass.
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NOT
USED
MF/HF
SUB LF
RIGHT/MONO
INPUT
WS2A
W2 ACTIVE
WX3AW2 Mono
W3 ACTIVE
WS2A
WX3AW3 Mono
NOT
USED
MF/HF
SUB LF
RIGHT/MONO
INPUT
Fig 11. W2 Active + Sub configuration using WX3AW2 mono card
Fig 12. W3 Active + Sub configuration using WX3AW3 mono card
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7 LEVELS
Each output level may be adjusted from -ve infinity to +6dB relative to its
nominal level. The system-specific plug-in boards include mid and high
frequency band attenuation to provide level matching for approximate
system balance when all controls are set to 0dB (assuming the use of
amplifiers with identical gains). It should be noted, therefore, that front
panel calibration would not necessarily indicate absolute band gains within
the WX3A. When setting up a system for the first time, the WX3A band
levels should be adjusted for desired balance and the settings noted for
future reference.
8 LIMITERS
The WX3A system controller features fast attack limiters to prevent power
amplifiers from clipping, thus providing speaker protection whilst preserving
full system headroom. The limiters are set by adjusting the limit threshold
switches to the value that matches the input sensitivity of the amplifier. A
system operated in this way, with amplifiers having a power rating as
recommended for the particular Wavefront system and used by
experienced professional sound engineers, should be sufficiently protected
from overdriving. Amplifier gain controls should normally be set at
maximum. Triggering of the limiter is indicated by a red LED on the front
panel.
Recommended amplifier powers for Wavefront Series loudspeakers are as
follows:
W1 300-400 watts per channel into 4 ohms
W2/W3 400-600 watts per channel into 4 ohms
W3P 550-800 watts per channel into 4 ohms
WS2A 550-800 watts per channel into 4 ohms
Limiter threshold settings may be altered by removing the top panel of the
WX3A case (two screws each side) to gain access to the main circuit
board.
The limiter threshold is set by a 16-way switch on each band. This is
located on the main circuit board behind each corresponding band level
control. The switches are labelled as follows:
BAND 1 S 1
BAND 2 S 2
BAND 3 S 3
BAND 4 S 4
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Threshold values corresponding to the switch settings are printed on the
main circuit board for easy reference when making adjustments.
They are:
012345 6789ABCDEF
0.2 0.4 0.5 0.7 0.9 1.1 1.3 1.4 1.6 1.8 2.0 2.2 2.3 2.5 2.7 2.9
If operated by inexperienced personnel or in situations where abuse is likely,
limiter switches can be backed off 2 or 3 positions to lower ‘safe’thresholds.
This will ensure that the output of the amplifiers cannot exceed the long-term
continuous power ratings of the drive units.
Each limiter may be defeated if required by moving jumper links J1-J4 on the
main circuit board to the left position.
JUMPER POSITION LIMITER
BAND 1 J1 RIGHT ON
LEFT OFF
BAND 2 J2 RIGHT ON
LEFT OFF
BAND 3 J3 RIGHT ON
LEFT OFF
BAND 4 J4 RIGHT ON
LEFT OFF
IMPORTANT NOTE
If another WX3A is to be driven from any of the outputs - for instance when a
WX3ASF provides the high-pass outputs for a WX3A configured for an active
W2 or W3 - the limiters should be defeated on those outputs to prevent them
from operating in advance of the limiters in the following units (see Fig 9).
9 WARRANTY
Martin Audio WX3A System 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.
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10 TECHNICAL SPECIFICATIONS
WX3A
INPUTS 2 Electronically Balanced
IMPEDANCE 36K ohms (18K ohms per leg single ended)
CMRR 67dB 20-10KHz
CONNECTORS 3 Pin female XLR
OUTPUTS 4 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 @ 25 Hz 12dB / octave
-3dB @ 35KHz 12 dB / octave
(ultimately set by system parameters)
DISTORTION+NOISE 0.009% THD @ 2V output (limiters cancelled)
SIGNAL+NOISE/ >97dB’s @ 2V output 20Hz –20KHz quasi
NOISE RATIO peak o/c input
LIMITERS Individual for each channel. With program
related attack times. Ratio 20:1. Threshold
range -12dBu to +12dbu, in 16 steps
INDICATORS 2-way stereo, 3/4 way-mono LED’s. Signal
present, threshold and LED’s on each band
PROTECTION Auto muting relays and soft start (4 seconds)
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: -250mA Type ‘T’(L)
100-120V: -500mA Type ‘T’(L)
DIMENSIONS (W) 482mm x (H) 44mm x (D) 211mm
(W) 19ins x (H) 1.75ins 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
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WX3A 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: [email protected]
The Martin Experience
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MARTIN AUDIO
LONDON
The Martin Experience
ENGLISH
WX3A System Controller
User’s Guide
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