Bowers & Wilkins HTM4 Diamond Manual page 6

4. Fine Tuning
Before fine tuning, double check that all the
connections in the installation are correct and secure.
Moving speakers further from the walls will reduce the
general level of bass. Space behind speakers also
helps to create an impression of depth. Conversely,
moving speakers closer to the walls will increase the
level of bass and potentially reduce the impression of
depth.
If you want to reduce the volume of bass without
moving the speakers further from the wall, fit the foam
plugs or, for less severe bass reduction, the foam rings
in the port tubes. Fitting a foam plug or ring in a port
tube is illustrated above.
If the sound is too harsh, increase the amount of
soft furnishing in the room (for example, use heavier
curtains), or reduce it if the sound is dull and lifeless.
Test for flutter echoes by clapping your hands and
listening for rapid repetitions. Reduce flutter echoes
by the use of irregular shaped surfaces such as
bookshelves and large pieces of furniture.
For the most discerning listening, remove the bass/
midrange grilles by gripping around their edges and
gently pulling them away from the cabinet.
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5. Running-In
The performance of your speaker may change subtly
during the initial listening period. If it 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 suspension 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.
6. Aftercare
800 Series Diamond cabinet surfaces will usually only
require dusting. We recommend you use the cloth
supplied with the product. If you wish to use an aerosol
or other cleaner, apply the cleaner onto the cloth, not
directly onto the product and test a small area first,
as some cleaning products may damage some of the
surfaces. Avoid products that are abrasive, or contain
acid, alkali or anti-bacterial agents. Do not use cleaning
agents on the drive units. Avoid touching the drive units
as damage may result.
Whenever Bowers & Wilkins speakers are finished
in real wood, the finest veneers are selected and
treated with an ultra-violet resistant lacquer to
minimise changes in colour over time. Nevertheless,
like all natural materials, the veneer will respond to
its environment and a degree of colour change is to
be expected. Colour differences may be rectified by
exposing all the veneer surfaces equally and evenly
to sunlight until the colour is uniform. This process
can take several days or even weeks, but may be
accelerated by careful use of an ultra-violet lamp.
Wood veneered surface should also be kept away from
direct sources of heat such as radiators and warm air
vents in order to minimise the possibility of the wood
veneer cracking.