Loudspeaker Installation; Before Connection - Panasonic RAMSA WS-A240 Operating Instructions Manual

LOUDSPEAKER INSTALLATION
The WS-A240 is equipped with six M8 x 25 threaded in-
serts that are molded into the enclosure. All attachments
to the enclosure should use these fittings. For stand mount-
ing, two thumbscrews are provided with the WS-A240,
which should be handtightened only. For suspended appli-
cations, forged shoulder eye-bolts are recommended. DO
NOT substitute any other fitting for these critical load-
bearing components.
Thumbscrew
Forged eye-bolt
RAMSA Part No. XVPBF25FZ
When mounting WS-A240 loudspeakers to a wall or ceil-
ing. either by hanging or with brackets, they should be se-
curely attached to the building structure. This requires
knowledge of building construction and load-bearing capac-
ities. If this information is unknown, installers should seek
the advice of an architect or structural engineer before at-
tempting such attachments.
The loudspeaker systems can be mounted vertically or
horizontally. When mounting horizontally, remove the four
screws fitting the front grill, rotate the grill 90 degrees and
re-install. Do not operate the WS-A240 without the protec-
tive grill in place.
When multiple WS-A240s are to be installed, best perfor-
mance will be realized when units are mounted in close prox-
imity to one another. Because high sound levels at low
frequencies will be realized, special care should be observed
to assure that structural resonances and vibrations do not
impair the sound quality.
BEFORE CONNECTION
Switch off power amplifier{s} before connecting the loud-
speaker(s}. After loudspeaker connection, be certain that
high level audio signals are not present before switching the
amplifiers on.
The nominal impedance of the WS-A240 is 8 ohms. Two
loudspeakers in parallel will have a nominal impedance of
4 ohms, which is the lowest impedance most amplifiers are
capable of driving. Be certain that the number of loudspeak-
ers connected in parallel does not result in a load impedance
that is below the rating of the amplifier.
Use the largest wire gauge speaker cable that is practical
to minimize DC resistance and losses due to cable length.
Note that the lower the impedance of the total speaker load,
the greater the losses in the wire.
POWER HANDLING CAPACITY
The rated power capacity of the WS-A240 is 400 watts in
accordance with the test procedure outlined in EIA (Elec-
tronic Industries Association) RS-426-A. This test method
employs white noise through RC high pass and low pass
filters to simulate the energy-frequency spectrum of typi-
cal program material. It is an excellent indicator of the ther-
mal power capacity of a loudspeaker system.
Because the WS-A240 is a subwoofer, it is subject to
mechanical power limitations, especially at very low fre-
quencies. The WS-SP2A Subwoofer Processor includes
à high pass filter that protects the WS-A240 from exces-
sive mechanical displacement at sub-audio frequencies.
The WS-SP2A should be used with WS-A240s at all times.
CAUTION:
Certain signals may result in excessive displacement of the
driver diaphragm, thereby damaging the loudspeaker. The
following conditions of operation should be avoided at all
times:
1. Shock noise caused by energizing or de-energizing mix-
ing consoles and peripheral equipment when the WS-
SP2A and the amplifiers are powered up.
2. Shock noise resulting from the connection or discon-
nection of input/output connectors with the system po-
wered up.
3. The use of condenser or omnidirectional microphones
for vocal applications without appropriate breath-pop
screens and/or high pass filters.
4. The switching on/off of phantom microphone power
with level controls up.
5. Continuous operation at very low frequencies from an
oscillator, synthesizer or other program source when
doubling distortion is evident in the loudspeaker.