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WARNINGS:
CAUTION: 120V versions of the product are
supplied with a power cord equipped with a
polarised plug. To prevent electric shock, match
wide blade of plug to wide slot, fully insert.
Ensure the plug is fully inserted into the wall
outlet or extension cord receptacle to prevent
blade or pin exposure.
To prevent fire or shock hazard, do not expose
this equipment to rain or moisture.
Observe all warnings on the equipment itself.
To avoid electrical shock, do not open the
enclosure or remove the amplifier from the rear
panel. There are no user serviceable parts
inside. Refer all service questions to an
authorised B&W dealer.
Ensure that the voltage indicated on the amplifier
panel matches that of the power supply.
The mains fuse holder is located on the back
panel of the amplifier module. Replacement fuse
must be of the same type and rating as supplied
and marked on the product.
The product does not require earthing
(grounding).
Ensure the product is adequately ventilated. Do
not prevent air from circulating round the rear
amplifier panel. Do not obscure or block the
openings in the panel. Do not use the product in
a rack, bookcase, cabinet or cupboard unless
the volume behind the product is adequately
ventilated to the room space.
Check that there are no cables under the carpet
that may be damaged by the spike feet.
Do not walk the product on the spike feet as this
may cause them to become detached from the
cabinet and cause damage.
Take care not to impale yourself with the spike
feet when moving the product.
Introduction
Thank you for purchasing the B&W ASW™2500
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™2500 has been designed for Home
Theatre installations and to augment the bass
performance of full-range speakers in 2-channel
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.
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 60
countries worldwide 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
(figure 1)
The easiest way to unpack the subwoofer and
avoid damage is as follows:
• Open the carton flaps right back and invert
the carton and contents.
• Lift the carton away from the product.
We recommend that you retain the packaging
for future use.
In addition to this manual, the carton should
contain:
1 Subwoofer
1 Accessory pack containing:
4 Rubber feet
4 Spike feet
4 Lock nuts
1 International warranty document
A tour of the subwoofer
(figure 2)
1 LINK OUT sockets
2 LINE OUT sockets
3 LINE IN sockets
4 VOLUME control
5 LOW-PASS FREQUENCY control
6 PHASE switch
7 LOW-PASS FILTER defeat switch
8 EQualisation switch
9 POWER On/Auto/Standby switch
10 Power/Standby indicator
11 Ventilation holes
12 Power input socket
13 Power isolator switch (230V versions only)
14 Fuse holder
Positioning the subwoofer
Because the subwoofer produces only low-
frequency sounds, positioning is less critical in
some respects compared to full-range speakers.
Directional information is much less precise and
you have more choice where to place the
speakers to good effect. This said, best results
are obtained if the subwoofer is placed between
the satellite speakers or in the vicinity of one of
them. If you use two subwoofers, it is best to put
one near each satellite speaker.
Placing the subwoofer behind the listeners, even
in surround sound installations, generally gives
inferior imaging, but may be an acceptable
compromise if domestic considerations dictate.
As with all speakers, the proximity of room
boundaries affects the sound. Bass is generally
increased as more surfaces come into close
proximity with the speakers. Unlike full-range
speakers, however, you can always restore the
correct overall system balance by adjusting the
volume level of the subwoofer. The more boost
you get from the room, the less hard the speaker
has to work; but there is a down side. Corner
positions often excite more low-frequency room
resonances, making the bass more uneven with
frequency. There is no substitute for experiment
as all rooms behave differently, so try the
subwoofer in a variety of positions before
making a final decision. A piece of music with a
bass line ascending or descending the musical
scale is useful for assessing the smoothness of
the bass response. Listen for exaggerated or
quiet notes. Having a separate subwoofer does
enable you to optimise for room resonances
independently from siting the satellite speakers
for best imaging.
If the subwoofer is to be used in a confined
space (eg in custom furniture), the space must be
ventilated to allow sufficient air to circulate and
cool the unit. Ask your dealer for advice.
The subwoofer is supplied with four spike feet.
The spikes pierce through carpet pile, giving a
firm support directly to the floor surface without
crushing the pile.
If the unit is to be placed on a vulnerable
surface, such as a wooden floor, either place a
protective disc under each spike or fit the four
rubber feet in place of the spikes.
When fitting either the rubber feet or the spike
feet, first screw the lock nuts fully onto the thread
and then screw the feet fully onto the threaded
inserts in the base of the cabinet. If the unit
rocks, loosen the relevant two opposing feet until
the support is firm, then re-tighten the lock nuts to
the inserts.
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 function of the subwoofer is to receive
signals from the amplification chain and, where
