Bowers & Wilkins CM Center, Owner'S Manual & Warranty

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television set with the speaker in place. Some have a
button especially for this purpose. If such feature is
fitted, switch off the set at the mains for 15 minutes
and switch on again – again with the speaker in place.
Merely putting the set into standby mode will not be
sufficient.
If you still have a problem, try moving the speaker
either forwards or backwards a little to get a more
favourable alignment, or space the speaker further
from the television until the distortion disappears.
Because of the higher magnetic field in front of the
speakers, magnetically sensitive articles (computer
discs, audio and video tapes, swipe cards, etc) should
be kept at least 0.2m from the speaker.
Connections
All connections should be made with the equipment
switched off.
There are 2 linked pairs of terminals on the back of the
speaker. For conventional connection, the terminal
links should remain in place (as delivered) and just one
pair of terminals connected to the amplifier. For bi-wire
connection, the terminal links should be removed and
each pair of terminals connected to the amplifier
independently. Bi-wiring can improve the resolution of
low-level detail. Figures 1a and 1b illustrate
conventional and bi-wire connection.
Ensure that the positive terminals on the speaker
( and coloured red) are connected to the
positive output terminal on the amplifier and the
negative terminals on the speaker (marked – and
coloured black) are connected to the negative output
terminal on the amplifier. Incorrect connection can
result in poor imaging and loss of bass.
Ask your dealer for advice when selecting speaker
cable. Keep its total impedance below the maximum
recommended in the speaker specification and use a
low inductance cable to avoid attenuation of high
frequencies.
Fine Tuning
Before fine tuning, make sure that all the connections
in the installation are correct and secure.
For greatest realism in home theatre installations, it is
important to balance the speakers and adjust the
acoustic image to match the size of the screen. With
smaller screens, it may be more realistic to have the
left and right speakers closer together than you might
for audio alone.
Adjust the levels of the three front speakers to get a
smooth transition of sounds as they pan across the
screen. Adjust the level of the surround speakers so
that, except for special effects, your attention is not
unduly attracted to them. Listen from a variety of
probable listening positions when deciding on the
optimum levels.
Moving the speaker further from the wall will generally
reduce the volume of bass. Conversely, moving the
speaker closer to the walls will increase the volume of
bass. If you want to reduce the volume of bass without
moving the speaker further from the wall, fit the foam
plug in the port tube as illustrated in Figure 2.
If the bass seems uneven with frequency, this will
most probably be due to resonance modes in the
listening room. Even small changes in the position of
the speakers or the listening position can have a
profound effect on how these resonances affect the
sound. Try moving the listening position a little
backwards or forwards. The presence and position of
large pieces of furniture can also influence resonant
modes.
If the sound is too bright, increasing the amount of
soft furnishing in the room (heavier curtains for
example) may help balance the sound. Conversely,
reducing the amount of soft furnishing may help
brighten a dull sound.
Some rooms suffer from "flutter echoes" – echoes that
"bounce" between parallel room boundaries. Flutter
echoes can colour the sound of the speakers in the
room. Test for flutter echoes by standing in the middle
of the room and clapping your hands. Flutter echoes
can be reduced by placing irregular shaped items or
non-reflective surfaces, bookshelves, rugs or pictures
for example, on one of the offending walls or floor.
Ensure that speaker stands are upright and firm on the
floor. Use carpet piercing spikes if appropriate and
adjust them to take up any unevenness.
Running-in Period
The performance of the speaker will change subtly
during the initial listening period. If the speaker has
been stored in a cold environment, the damping
compounds and suspension materials of the drive
units will take some time to recover their correct
mechanical properties. The drive unit suspensions will
also loosen up during the first hours of use. The time
taken for the speaker to achieve its intended
performance will vary depending on previous storage
conditions and how it is used. As a guide, allow up to
a week for the temperature effects to stabilise and
15 hours of average use for the mechanical parts to
attain their intended design characteristics.
However, longer run-in periods (as long as a month)
have been reported and there is evidence to suggest
that this has little to do with the speaker changing and
more to do with the listener getting used to the new
sound. This is especially so with highly revealing
speakers such as these, where there may be a
significant increase in the amount of detail compared
with what the listener has previously been used to; the
sound may at first appear too "up front" and perhaps
a little hard. After an extended period of time, the
sound will seem to mellow, but without losing clarity
and detail.
Aftercare
The cabinet surfaces usually only require dusting. If
you wish to use an aerosol or other cleaner, remove
the grille first by gently pulling it away from the
cabinet. Spray aerosols onto the cleaning cloth, not
directly onto the product. Test a small area first, as
some cleaning products may damage some of the
surfaces. Avoid products that are abrasive, or contain
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