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Signal Source
Use a signal source which is suitable for
the type of analyser being used. Do not
use a noise generator which is integrated
into a mixing console, since these signal
generators tend to have a very coarse
spectrum content and are not intended to
be used for measurement purposes.
Analyser
Any professional quality real time analyser
or tracking plotter can be used. (
octave analysis is usually sufficient for
frequency response balancing)
3.4 NEAR FIELD MEASUREMENT.
This measurement gives an indication of
the direct sound radiation of the loud-
speaker below 1kHz.
• Set the microphone 1m away from the
loudspeaker on the acoustic axis. (See
Fig 2.1 and 2.2)
• Measure the frequency response of
the speaker, and adjust the tone controls
to achieve a flat frequency response
below 1kHz.
Make sure that any sound reflecting ob-
jects such as chairs etc. are removed
from the close proximity of the loud-
speaker.
3.5 LISTENING POSITION MEASURE-
MENT.
Once the near field frequency response
measurement has been made, the fre-
quency response at the listening position
can be determined by the same means.
When comparing the results, the following
items should be noted.
High frequency roll-off
This is due to the following physical fac-
tors:
• Increasing room and air absorption
with higher frequencies.
• Increasing loudspeaker and micro-
phone directivity with increasing fre-
quency.
Low frequency irregularities.
These are caused by
• Insufficient standing wave absorption
in the control room.
• Reflections from nearby boundaries
(Floor, ceiling, walls) interfering with direct
sound.
Incorrect vertical speaker alignment can
cause interference dips at the upper
crossover frequency (around 3.2kHz).
Hence care should be taken aiming the
speaker correctly towards the listening
position. (See Fig 3.)
1
1
/
or
/
3
1
4. OVERLOAD INDICATORS
4. OVERLOAD INDICATORS
4. OVERLOAD INDICATORS
4. OVERLOAD INDICATORS
4. OVERLOAD INDICATORS
Each speaker is provided with two LED's
marked 'CLIP PROTECT (FAULT)' and
'READY'. The green 'READY' LED indi-
cates that the amplifier system power is
switched on, and that the speaker is
ready for use. The red 'CLIP PROTECT
(FAULT)' LED indicates that the amplifier
system is overloaded or that the driver
protection circuit is activated. If the red
LED lights, reduce the signal level so that
the LED stops blinking. If this LED stays lit
constantly, then the amplifier thermal
protection circuitry has activated. Let the
amplifier cool down, and ensure that the
amplifier is adequately ventilated.
5. MAINTENANCE
5. MAINTENANCE
5. MAINTENANCE
5. MAINTENANCE
5. MAINTENANCE
There are no user serviceable parts within
the amplifier unit. Any maintenance of the
unit should only be undertaken by quali-
fied service personnel.
Ensure that only fuses of the appropriate
voltage and current ratings are used if a
fuse has to be replaced.
REMEMBER to disconnect the power
supply by removal of the mains cable
before changing a fuse.
Clean the amplifier unit's air filter every six
months, or more frequently in dusty envi-
ronments. The air filter is located behind
the grille, found to the left of the front
panel. The air filter can be cleaned with a
vacuum cleaner without removing the
grille.
6. SAFETY CONSIDERATIONS
6. SAFETY CONSIDERATIONS
6. SAFETY CONSIDERATIONS
6. SAFETY CONSIDERATIONS
6. SAFETY CONSIDERATIONS
Although the 1034B has been designed in
accordance with international safety stan-
dards, to ensure safe operation and to
maintain the instrument under safe oper-
ating conditions, the following warnings
and cautions should be observed.
Servicing and adjustment should only be
performed by qualified service personnel.
Opening the amplifier's front panel is
strictly prohibited except by such persons
who are aware of the hazards involved.
It is forbidden to use this product with an
unearthed mains cable, which may lead
to personal injury.
Warning!
This equipment is capable of delivering
sound pressure levels in excess of 85dB,
which may cause permanent hearing
damage.
7. GUARANTEE
7. GUARANTEE
7. GUARANTEE
7. GUARANTEE
7. GUARANTEE
This product is guaranteed for a period of
ONE year against faults in materials or
workmanship. Refer to supplier for full
sales and guarantee terms.
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