Electrical Connections - Bowers & Wilkins ASW 500 Owner's Manual

Introduction
Thank you for purchasing the B&W ASW™500
Active Subwoofer.
Since its foundation in 1966, the continuing
philosophy of B&W has been the quest for
perfect sound reproduction. Inspired by the
company's founder, the late John Bowers, this
quest has entailed not only high investment in
audio technology and innovation but also an
abiding appreciation of music and the demands
of film sound to ensure that the technology is put
to maximum effect.
The ASW™500 has been designed for Home
Theatre installations and to augment the bass
performance of 'full range' speakers in stereo
audio use. Adding the subwoofer to your
system not only extends the bass to lower
frequencies, it improves the midrange clarity
by reducing the low-frequency demands on
your existing speakers.
The subwoofer is magnetically shielded for use
close to a television screen.
Please read through this manual fully before
using the subwoofer. All sound installations
require some planning and experimentation if
you are to get the best out of the products used
and this manual will guide you in this process.
As the subwoofer is connected to the electricity
power supply, it is important that you familiarise
yourself with the safety instructions and heed
all warnings.
Keep this manual in a safe place for future
reference.
B&W loudspeakers are distributed to over
50 countries world-wide and we maintain an
international network of carefully chosen and
dedicated distributors. If you have a problem
which your dealer cannot resolve, our distributors
will be more than willing to assist you.
Unpacking
To avoid damage to the cabinet (and to minimise
strain to yourself) when unpacking, we suggest
that you adopt the following procedure:
Remove any staples from the open flaps
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of the carton.
Fold the open flaps right back and invert
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the carton and contents.
Lift the carton away from the product.
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Remove the upper layer inner packing to reveal
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the base of the cabinet.
Open the polythene bag and turn the cabinet
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right way up.
We recommend that you retain the packaging
for future use.
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Positioning the ASW™500
Because the ASW™500 produces only very low
notes, positioning is easier than for full-range
speakers. Best results are obtained if the
ASW™500 is placed between the front
speakers. If you use two ASW™500s then it is
best to put one near each front speaker.
The ASW™500 is supplied with conical feet that
raise the base of the cabinet clear of the floor to
allow the down facing port to operate correctly.
Do not reduce this clearance or bass
performance will be degraded.
If the ASW™500 is to be used in a confined
space (e.g. in custom furniture), the space must
be ventilated to allow sufficient air to circulate
and cool the unit. Depending on the volume of
the enclosed space, it may be necessary to
provide ventilation into the room. Ask your
dealer for advice.

Electrical connections

Disconnect all sound system equipment from the
power supply until the signal connections have
been made and checked. This avoids the risk of
damage whilst connections are made or broken.
The ASW™500 accepts inputs and outputs at
either line level (RCA Phono sockets) or at
speaker level.
However, you must not use a mixture of line level
and speaker level connections in the same
installation.
Stereo Audio (Using Line Level
Connections)
(figure 1)
This is the preferred method, and is suitable for
use when you have a separate pre-amplifier and
power amplifier or an external link between the
pre- and power amplifier sections in an
integrated amplifier.
Connect the pre-amplifier left and right line level
output socket(s) to the left and right LINE IN
socket(s) of the ASW™500 and the same
channel LINE OUT socket(s) of the ASW™500
to the line level input socket(s) of the power
amplifier (figure 1).
In both cases, the satellite speakers are
connected to the power amplifier output in the
normal way. However, the signal fed to them
now has the deep bass removed.
Stereo Audio (Using Speaker Level
Connections)
(figure 2)
Use this method when you have an integrated
amplifier with no access to a line level signal.
Connect the speaker level outputs of the power
amplifier to the relevant channel INPUT FROM
AMPLIFIER spring terminals of the ASW™500,
taking care to connect positive to positive and
negative to negative (figure 2). Connect the
satellite speakers to the relevant channel
OUTPUT TO SPEAKERS terminals of the
ASW™500.
With this method of connection, the ASW™500
drive unit is still powered by its own internal
amplifier and the signal fed to the satellite
speakers has the deep bass removed.
Home Theatre
(figures 3, 4 & 5)
If your decoder has a separate subwoofer
output, connect it to one channel only (left or
right) LINE IN socket (for line level) or FROM
AMPLIFIER terminals (for speaker level) of the
ASW™500 and feed the left and right front
speakers directly from the decoder in the normal
way (not via the ASW™500), using a separate
power amplifier if necessary (figure 3).
If your decoder has no dedicated subwoofer
output, connect the ASW™500 to the left and
right front outputs of the decoder and your left
and right front speakers via the ASW™500,
using either the LINE IN/LINE OUT sockets with
separate power amplifiers (figure 4) or the
FROM AMPLIFIER/OUTPUT TO SPEAKERS
terminals (figure 5) in the same manner as
described above for stereo amplifiers.
Using more than one ASW™500
Any number of ASW™500 units can be daisy
chained together in either two-channel mono or
single-channel mode. Using two or more units in
a single installation can improve performance in
the following ways:
Cope with larger spaces.
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Enable greater maximum sound output – often
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useful for effectively reproducing special effects
in Home Theatre applications.
If using line level connections, connect up the
first ASW™500 as described above and then
connect its LINK OUT socket(s) to the
corresponding LINE IN socket(s) of the second
ASW™500. Continue this process as required
for more units.
If using speaker level connections, connect the
first ASW™500 as described above and
connect the FROM AMPLIFIER terminals of the
second ASW™500 to either the corresponding
power amplifier output terminals or the
corresponding FROM AMPLIFIER terminals on the
first ASW™500, whichever is more convenient.
Double Check the Connections
Before auditioning the sound quality of your new
installation and fine tuning it, double check the
connections.
The phasing is correct – There should be no
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positive to negative connections (this applies to
speaker level interconnects). If something is out
of phase you may get a fuzzy sound with an
imprecise and floating image, a lack of bass
or a combination of the two.
There are no left to right mix-ups – This can
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result, for example, in the orchestra being the
wrong way round or, more disastrously, sounds
on your home theatre going in the opposite
direction to the action on the screen.