Wharfedale Pro Pro WPG-331 User manual

Thank you for buying a Wharfedale WPG Series Pro Graphic Equalizer Unit.
These units can be used with other Wharfedale Pro Units of which details can be obtained from your dealer.
EVP Series of High Performance Loudspeakers
WPG-202 Two channel Electronic Crossover • SE Series of Power Amplifiers
Lix Series of High Performance Loudspeakers
Action Series Mixers
The information in this manual is subject to change without notice.
All rights reserved © 1998 Wharfedale Pro, IAG group
WHARFEDALE website :www.wharfedale.co.uk

WPG SERIES
PROFESSIONAL GRAPHIC
EQUALIZERS
WPG-331
(single channel)
WPG-315
(dual channel)
EQ
BYPASS
EQ
RANGE PHASE
SIGNAL
PEAK
-12
6
0
6
+12
LEVEL
+6
2
-6
2
0
20 25 31.5 40 50 63 80 100 125 160 200 250 315 400 500 630 800 1K 1.2K 1.6K 2K 2.5K 3.1K 4K 5K 6.3K 8K 10K 12.5K 16K 20K
OUT
IN
6dB
12dB
-12 +12
dB
HPF
10 200
Hz
NORMAL
REVERSE POWER
PEAK
SIGNAL
POWER
OUT
BYPASS
IN
12dB
6dB
RANGE
400
100
-12
+12
6
0
6
25 40 63 630250
160 400 1.6K
1K 2.5K
IN PEAK
SIGNAL
OUT
4K 6.3K 10K 16K
BYPASS
RANGE
6dB
12dB
-12
6
+12
6
0
25 40 63 100 160 250 2.5K
1K
630 1.6K 6.3K
4K 10K
-6
2
+6
0
2
16K
CHANNEL 1 CHANNEL 2
CHANNEL 1 CHANNEL 2
VOLUME
0 10 0 10 -6
+6
2
0
2

Unpacking
All Wharfedale Pro products are fully
checked before leaving the factory.
After unpacking please inspect
contents for any physical damage.
Please retain the shipping carton if possible and internal
packing material in case the unit needs to be returned.
Please check as soon as possible the unit is functioning
correctly. In the event of any damage please contact your
dealer immediately so that a written claim for damages can
be made.
Wharfedale Pro Limited Warranty
Wharfedale Pro WPG Series graphic equalisers are
warranted to be clear of defects in construction, materials
and malfunction under normal operating conditions for a
period of 3 years from the original date of purchase
providing the unit has only been used for its intended
purpose. Wharfedale will during the warranty, and at its
own discretion, undertake to make repairs at no charge if
the product has been delivered to Wharfedale Pro by a
Wharfedale Dealer. Wharfedale exclude normal exterior
wear to finish and cannot be held responsible for any
system malfunction due to abuse or using the units beyond
the limits and conditions as stated within the specified
ratings. Wharfedale shall not be liable for any
WPG SERIES • PROFESSIONAL
This warranty is only valid providing:
i) Warranty applies to original purchaser only (warranty not
transferable)
ii) Warranty card must be filled in fully and returned to
Wharfedale Pro within 30 days from date of purchase.
Failure to do so will not affect your statutory rights.
iv) Unit must be returned with original sales receipt or other
proof of purchase.
v) Unit is repaired by Wharfedale or authorised service
agent only.
These terms do not infringe your statutory rights.
The WHARFEDALE Wireless Works was established in
1932 by Gilbert Briggs who soon established a reputation
as one of the most innovative loudspeaker engineers of
his generation. His company was at the leading edge of
an exciting new technology which was dedicated to
bringing the pleasure of music and entertainment into
people’s homes. As the technology advanced Wharfedale
gave many music lovers their first taste of High Fidelity,
mounting a series of live sound demonstrations which
excited the audio world and heralded the birth of the
modern hi-fi loudspeaker.
Today Wharfedale Pro takes the same uncompromising
approach to the design and manufacturing of every audio
product, using high-quality components and state-of-the-
art testing equipment to ensure consistency and high
performance. At Wharfedale we design and build all of our
products and we control all the variables, so that we don’t
have to compromise our design goals.
Wharfedale Pro WPG series of Graphic Equalizers are
high quality units suitable for stage, club and studio use.
Using proven circuitry they are straightforward to use,
reliable in operation and capable of excellent
performance.
WPG - 331 Single channel Graphic equalizer
l31 bands of equalisation, Third Octave at standard ISO
frequencies
lBalanced inputs and outputs with XLR and jack
connectors
lConstant “Q” multi-feedback bandpass filter circuits
lVery low THD and background noise levels
lSignal level and Peak level LED indicators
lVariable High-Pass Filter 10 Hz to 200Hz
lPhase reverse switch
l±6dB or ±12dB operating level switch
lEQ Bypass switch
WPG - 315 Two channel Graphic equalizer
lAs WPG-331 except 15 equalisation bands per channel
and without high-pass filter

GRAPHIC EQUALISER MANUAL
PLEASE READ THESE IMPORTANT INSTRUCTIONS
BEFORE USING THE EQUALISER.
SAFETY INSTRUCTIONS
To reduce the risk of electric shock the user should not
remove the cover. All operating and safety instructions
should be followed. The unit should be kept clear of
water, fluids and moisture and not be operated in damp
conditions. The unit should be operated in a well
ventilated environment. The unit should be kept away
from excessive heat sources such as radiators and if
racked with other power amplifiers there should be a
free air flow to vent out the heat produced (check with
dealer). This graphic equaliser must only be used with
the Wharfedale external power unit provided.This
power unit provides a 19 volt ac supply and its output
cable must be plugged into the matching socket on the
rear panel of the equaliser. This must be done
BEFORE the power unit is plugged into the mains
power supply. The power cable should be disconnected
during prolonged non usage.The user should not
attempt to service the unit or do anything to the unit in
any way except those things described in this manual.
For service and repair your dealer should be contacted.
This unit complies with relevant safety regulations.
POWER NOTICE FOR SAFETY
All British and European countries have a nominal
230v mains power supply. In practice this varies
between 220v and 240v. In the USA the main power
supply is 115v and in Japan 100v. The power unit is
factory set to the correct voltage and this can be
checked by referring to the label on the unit. If the
equaliser is used in a country having a different
supply voltage then a new power unit will be
required and you should consult your dealer. There
are no user serviceable parts within the power unit
or the equaliser and high voltages are present. DO
NOT remove the covers! Ensure that all the audio
connections are made before the mains supply is
connected and switched on.
1. Power switch, when depressed the power is
switched on.
2. The Power LED illuminates when the power is on.
3. Equaliser sliders (WPG- 331). 31 bands of
equaliser adjustment are provided at ISO 1/3 rd octave
frequencies.
4. Equaliser sliders (WPG- 315). 15 bands of
equaliser adjustment are provided for each channel at
ISO 2/3 rd octave frequencies.
5. The Bypass switch bypasses the complete unit by
linking the inputs directly to the outputs.
6. The Level switch enables the range of “boosting” or
“cutting” to be ±6dB or ±12dB. “Boosting” a frequency
band is achieved by moving a slider upwards towards
the “+” end and this increases the level of the chosen
frequency. “Cutting” a frequency band is achieved by
moving a slider downwards towards the “-” end and this
decreases the level of the chosen frequency.
7. The level rotary pot adjusts the sensitivity of the
equalisers input stage by ±12dB. This allows an
accurate level matching with a large range of sources.
The maximum output is +22dBm.
8. The signal LED indicates the presence of a signal
from an external source.
9. The peak LED indicates an output level that is
reaching or exceeding +22dB level and so causing
overload distortion. The signal level input then needs to
be reduced.
10. The HPF rotary pot (only on the WPG-331) is a
high pass filter that allows for a specific roll-off
frequency to be selected. Useful for tuning in at certain
frequency points and removing unwanted low
frequency signals.
11. Phase normal/reverse switch (only on the WPG-
331)
The switch inverts input signal by 180°. This enables
correct phase matching.
710
594
3
86
11 12
7

connections. If however, the system has already been
working perfectly and the graphic is suspect, follow the
basic fault finding procedure given. If this does not
produce any results, contact your dealer, who will be able
to solve the problem quickly. Most malfunctions can be
traced to cable (input, output and mains) failure or to the
connections.
Each input channel is electronically balanced with one
female XLR connector. In accordance with IEC and
AES/ANSI standards the wiring mode is Pin 1 Ground, Pin
2 Hot and Pin 3 Cold. The 1/4” Jack socket is also wired
in parallel with the XLR’s. The Tip is Hot, the ring is Cold
and the Sleeve is Ground.
Balanced Operation: Use only when driving from a true
balanced source and driving to a true balanced
destination. Either transformer balanced or with active
drive. Connect the input between pins 2 and 3 with pin 2
positive. Do not connect pin 1. Attach the shield to
connector case (chassis ground). Connect the output
between pins 2 and 3 with pin 2 positive. Do not connect
pin 1. Do not connect the shield at this end to anything.
Unbalanced Operation: Connect the input between pins
2 and 1 with pin 2 positive and pin 1 earth (signal ground).
Short pin 3 to pin 1. Attached the shield to connector case
(chassis ground). Connect the output between pins 2 and
1 with pin 2 positive. Leave pin 3 open - Do not short it to
pin 1. Do not connect the shield at this end to anything.
Venue/room equalisation. The sound of any system will
sound different and vary with each location. Each location
will have different acoustic properties which will give it its
own distinctive characteristic. This is due to the reflection
and absorption rates of sound within the audio spectrum
of different venues. Though your source material may be
reasonably flat, the sound that is actually delivered to an
audiences ears after reflection and absorption is not.
Feedback control
Sound system feedback (howling or squealing) occurs
when the the sound waves originating at the speaker
return to the microphone and are re-amplified causing the
system to oscillate at its natural resonance frequency.
Many of the effects of feedback - an unpredictable
alteration of the frequency response with changes in
system gain, an increase in reverberation time, and
system instability giving rise to howl, can be reduced with
Description
There are two models, the WPG-331 and the WPG-315
and they fit standard 1U, 19” (482mm) racks. These
equalisers are housed in steel cases suitable for
mounting in professional flight cases.
Operating
Equalisation is the adjustment of the frequency
response of an audio system, regardless of level, to
add or subtract level at particular frequencies for an
improved sound. Graphic Equalizers have become an
ideal tool for control over the total audio response. In most
audio systems careful equalisation can make the
difference between a poor and a superior sound quality.
Before switching on the graphic equaliser ensure that all
the audio inputs are connected and that the mains
connections are safely and securely connected at the
supply and at the power unit.
All internal servicing must be referred to qualified
service personnel with access to technical
documentation but if the unit fails to work the user
can apply a few basic checks to locate certain
problems.
i) If the Power LED is not on:-
Check that the power switch is set to on; that the power
unit is plugged into the graphic equaliser and that the
power unit is plugged into the mains supply.
ii) If a system has been set up, and the graphic is thought
not to be functioning, please check the system
WPG SERIES • PROFESSIONAL
12
3
GROUND
+ HOT
- COLD
TIP (+ HOT )
SLEEVE/GROUND
RING (- COLD)
XLR WIRING 1/4’ STEREO
JACK WIRING
REAR PANEL DIAGRAM
WPG 315

GRAPHIC EQUALISER MANUAL
SIGNAL INPUT
MIC, CD etc. TO MIXER MIXER
OUTPUT
INPUT TO
GRAPHIC EQUALISER
OUTPUTS FROM GRAPHIC
EQUALISERTO CROSSOVER
INPUTS TO CROSSOVER
SEPARATE
HIGH/MID
AND LOW
OUTPUTS TO
AMPLIFIER(S)
FROM
CROSSOVER
INPUTS TO AMPLIFIER(S) SEPARATE
LOW
SPEAKER
OUTPUT TO
LOW
FREQUENCY
SPEAKER
FROM
AMPLIFIER
SEPARATE
HIGH/MID
SPEAKER
OUTPUT TO
HIGH/MID
SPEAKER
FROM
AMPLIFIER
TYPICAL WIRING DIAGRAM FOR THE WPG - 315/331 SERIES CROSSOVER IN SYSTEM SETUP
equaliser use. There are three types of feedback, i)
feedback paths direct from the speakers, ii) feedback from
early reflections and iii) feedback from diffused
reverberation.The simplest way to cure type (i) feedback
is to re-direct the loudspeakers (front of house and
monitors) away from the microphone(s) so that the signal
picked up is too small to cause howl. Type (ii) feedback
can be more difficult to control by speaker re-direction.
Type (iii) feedback can be controlled by careful placement
and some trial and error movements of the loudspeakers
may cure this. This is nearly impossible at low frequency,
since the aiming of an omni-directional frequency source
(low,bass) is not possible These initial simple methods are
not always successful. This is where the graphic equaliser
can achieve beneficial, quick results. The feedback signal
can be located and ‘notched’ out by locating the frequency
that is most likely causing the howl and applying cut
(reduction) of level at this frequency. Eventually the
problem frequency(s) will be found and feedback cured.
There may be feedback occurring at two or more
frequencies. The same procedure will stop the feedback.
By matching the feedback note with the notes on a
keyboard or guitar and knowing the relationship of
frequency with musical notes the howl can be matched
and the band reduced, so if the howl matched the note ‘A’
you would reduce the slider 4.0 kHz as A = 4.40 kHz.
Monitor Equalisation
With amplified instruments on stage the monitor sound
can become muddy and unintelligible. The equaliser can
be inserted in between the mixer monitor output and the
monitor amplifier and be used to tailor the sound of the
monitor to cut through the onstage sound. Normally a
suitable vocal sound will be obtained if the response
above 3kHz and below 500Hz is rolled off.
Shaping Equalisation (creative)
This is where the the equaliser can be used either in the
studio or on stage to emphasise a specific tonal quality of
an instrument or sound source to create a new sound.

FREQUENCY RESPONSE:
THD:
SIGNAL TO NOISE RATIO (ref. +20dBm):
FILTER FREQUENCIES: WPG315
FILTER FREQUENCIES: WPG331
MAXIMUM BOOST AND CUT GAIN:
LEVEL CONTROL RANGE:
INPUT IMPEDANCE:
OUTPUT IMPEDANCE:
MAX OUTPUT LEVEL:
MAX INPUT LEVEL:
HIGH PASS FILTER RANGE: WPG331
POWER CONSUMPTION:
POWER:
DIMENSIONS: (HEIGHT • WIDTH • DEPTH)
WEIGHT:
10Hz - 30kHz ± 1dB
< 0.03% 20-20kHz
114dB
25Hz, 40Hz, 63Hz, 100Hz, 160Hz, 250Hz, 400Hz, 630Hz,
1kHz, 1.6kHz, 2.5kHz, 4kHz, 6.3kHz, 10kHz, 16kHz
20Hz, 25Hz, 31.5Hz, 40Hz, 50Hz, 63Hz, 80Hz, 100Hz, 125Hz,
160Hz, 200Hz, 250Hz, 315Hz, 400Hz, 500Hz, 630Hz,
800Hz,1kHz, 1.2kHz, 1.6kHz, 2kHz, 2.5kHz, 3.1kHz,4kHz,
5kHz, 6.3kHz, 8kHz, 10kHz, 12kHz, 16kHz, 20kHz
±12dB
±12dB
10K ohm (BALANCED)
<600 ohms (BALANCED)
+22dBm (BALANCED) • +22dBm (UNBALANCED)
+22dBm (BALANCED) • +22dBm (UNBALANCED)
10~200Hz 18dB/Octave
12 WATTS
95V~130 VOLTS AC, 50 - 60HZ
190V~ 250 VOLTS AC, 50 - 60HZ
483 x 160 x 44 mm / 19 x 6.3 x 1.7 inches
3Kg (6lbs)
TECHNICAL SPECIFICATION
WPG SERIES • PROFESSIONAL
POWER SUPPLY FOR WPG SERIES GRAPHIC EQUALISERS.
UK DISRIBUTED UNITS COME WITH FITTED MAINS PLUG, 250V
13 AMP, BS1363/A I.S.40/A

GRAPHIC EQUALISER MANUAL
2
3
112
BALANCED OUTPUT SIGNAL DIRECTION INPUT toWharfedale Pro unit
BALANCED INPUTWIRINGTOWHARFEDALE PRO UNIT WITH XLR CONNECTORS
+
+3
Ground (earth) CABLE Only connect ground if hum occurs
12
BALANCED OUTPUT SIGNAL DIRECTION INPUT toWharfedale Pro unit
BALANCED INPUTWIRINGTOWHARFEDALE PRO UNIT WITH 1/4" JACK to XLR CONNECTORS
+
+3
Ground (earth) CABLE Only connect ground if hum occurs
TIP
RING
SLEEVE
BALANCED OUTPUT SIGNAL DIRECTION INPUT toWharfedale Pro unit
BALANCED INPUTWIRINGTOWHARFEDALE PRO UNIT WITH STEREO 1/4" JACK to XLR CONNECTORS
+
+
Ground (earth) CABLE Only connect ground if hum occurs
TIP
RING
SLEEVE
TIP
RING
SLEEVE
2
3
1
BALANCED OUTPUT SIGNAL DIRECTION INPUT to
Wharfedale Pro unit
BALANCED INPUTWIRINGTOWHARFEDALE PRO UNIT WITH XLR CONNECTORS to STEREO 1/4" JACK
+
+
Ground (earth) CABLE Only connect ground if hum occurs
TIP
RING
SLEEVE
OUTPUT Wharfedale Pro unit SIGNAL DIRECTION INPUT
UNBALANCED INPUT AND OUTPUTWIRING WITH MONO 1/4" JACK CONNECTIONS
+
+
Ground (earth) CABLE
TIP
SLEEVE
TIP
SLEEVE
21 12
OUTPUT fromWharfedale Pro unit SIGNAL DIRECTION BALANCED INPUT
BALANCED OUTPUT WIRING FROMWHARFEDALE PRO UNIT WITH XLR CONNECTORSTO BALANCED UNIT
Ground (earth) CABLE Only connect ground if hum occurs
OUTPUT SIGNAL DIRECTION INPUT toWharfedale Pro unit
A great deal of mistakes in sound
installations can be down to wrongly
wired audio connections. It is
important that the connections are
correct to suit your system.
Unbalanced System
An unbalanced audio system is
typically a single conductor shielded
with the centre conductor relaying the
signal and the shield at ground.
Balanced System
Using a balanced audio system is
where a two conductor shielded cable
has each of the two centre conductors
carrying the signal but of opposite
phase. This gives each conductor an
equal but inverted potential difference
from that of the ground.
It is recommend that you use balanced
audio connections if the unit before
your graphic equaliser has a balanced
output. This will eliminate interference
such as mains hum. For the best
results common grounding should be
avoided. This means not connecting
the ground on both the graphic
equaliser input and output connectors.
Wharfedale Pro advise that you
connect the ground (shield) of the
input connecting cable to the ground of
the signal source while making sure
the ground (shield) is not connected to
the graphic equaliser input connector.
The output cable connector from the
graphic equaliser if connecting to
another unit should have the ground
(shield) connected. The input
connector ground (shield) to the
following unit should not be connected.
This is the process by which the
ground (shield) is connected (tied) at
the source unit but is not connected to
the destination unit. If hum develops in
some instances the ground (shield)
can be connected on the input. Some
manufacturers have units that
recommend that the input connector
ground (shield) is tied and the output
disconnected. In this instance you may
need to connect the input connector
ground (shield) going to the input of
the Wharfedale Pro unit.
If an unbalanced system is used with
XLR connections please connect pin 3
to pin 1 (ground) of the connector. This
will mean that pin 2 transports the
positive (+ / hot) signal. If pin 1 and 3
are not connected this results in the
negative (- / cold) input being ‘open’.
This will give an audible degradation of
the signal to noise ratio. This would
relate to both the input and output
connectors and involve the cable
ground (shield) connected at both.
Please note that some manufacturers
run their units with pin 2 (- / cold) and
pin 3 (+ / hot). This should be looked
out for and then the wiring could be
modified with labelled cables so that
connections of + / hot go to their
corresponding + / hot etc. Some
manufacturers run their units with
balanced inputs and unbalanced
outputs , therefore care should be
taken with the connections when
inserted into the system.