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Cone
Resonance
Tester |
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The
BA625
measures
the
resonant
frequency
of
speaker
cones
in
order
to
provide
a
simple
and
easily
verified
parameter
for
quality
control.
It
has
been
designed
to
be
robust,
accurate
and
easy
to
use.
The
unit
includes
a
frequency
generator
with
crystal
controlled
digital
Display.
The
oscillator
operates
in
the
range
10
to
2000
Hz
and
has
2
switchable
ranges.
The
oscillator
has
both
Course
and
fine
adjustment
to
make
setting
straightforward.
The
volume
can
be
continuously
varied
up
to
30
Watts,
and
has
a
switch
to
mute
the
drive
when
not
required.
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The
motion
of
the
cone
is
measured
using
a
specially
developed
positional
measurement
sensor.
This
uses
a
modulated
infrared
beam
and
so
is
unaffected
by
ambient
light
levels
or
fluorescent
lamps.
This
is
a
known
problem
with
some
other
measurement
techniques.
The
signal
amplitude,
measured
by
the
sensor
is
displayed
on
an
analogue
meter.
This
has
a
sensitivity
control
for
adjustment
of
the
optimum
signal
reading
from
the
sensor.
The
BA625
is
designed
to
be
used
in
conjunction
with
a
test
jig
which
comprises
of
a
drive
speaker
mounted
in
a
cabinet,
with
a
support
ring
fixture
mounted
above
this
which
holds
the
relevant
cones
to
test,
and
suitable
bungs
to
fit
the
cones.
The
semi-Automatic
tester
is
an
enhanced
version.
This
unit
applies
a
sweep
frequency
and
analyses
the
frequency
response
using
a
Fast
Fourier
Transform.
This
makes
it
possible
to
test
Cones
or
spiders
with
much
smaller
signals
and
in
the
presence
of
noise.
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Fig
1 |
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The
part
being
tested
is
selected
on
the
screen
above
(Fig
1).
The
required
jig
(rings
and
bungs)
and
the
specification
are
then
displayed.
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The
picture
above
shows
a
typical
PC
display
for
a
cone.
The
image
on
the
right
is
the
raw
signal.
The
image
on
the
left
is
the
signal
after
FFT
processing.
After
an
FFT
it
is
much
easier
to
identify
the
resonant
frequency.
The
result
is
checked
against
the
cone
spec
and
"Pass"
or
"Fail"
displayed.
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All
test
results
can
be
saved
in
an
ACCESS
database. |
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Specifications
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 Dimentions:
350mm(W),
180mm(D),
60mm(H)
Front,
110mm(H)
Rear. |
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Frequency
Range:
10
-
2000
Hz. |
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Accuracy:
+/-
0.1%
of
full
scale. |
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Displays:
12mm
LCD
4.5
digit
(frequency),
Moving
coil
meter
(signal
power). |
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Output
Power:
30
Watts
@
8
ohms. |
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| Manual
Adjustments: |
Frequency
Range |
| Frequency
Course |
| Frequency
Fine |
| Output
Volume |
| Sensor
Sensitivity |
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Power
Supply:
Optional
110V
/
240V
A.C.
50
Hz. |
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Sensor
Dimensions:
120mm(L),
27mm(D),
Cable
2
metres. |
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Sensor
Type:
Integral
Modulated
Infra-red
transmitter
-
receiver. |
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Flexible
Arm:
Comprising
of
a
screw
base,
a
500mm
fully
flexible
linkage
arm
and
sensor
clamp.
Made
from
glass-reinforced
nylon
and
high
quality
stainless
steel. |
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| Part
No |
Description |
| BA625 |
Cone
Resonance
Tester |
| BA625-C |
Cone
Resonance
Tester
-
Automatic/manual |
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