7
25. Mounting – Do not place this product on an
unstable stand, tripod, bracket or table. The
product may fall causing serious injury and serious
damage. Any mounting of the product should
follow the manufacturer’s instructions.
Do not expose the device to rain, use it near water or
in damp or wet conditions, or place containers on it
containing liquids which might spill into any openings.
When setting up the device, make sure that the AC
outlet you are using is easily accessible. If some
trouble or malfunction occurs, immediately turn off the
power switch and disconnect the plug from the outlet.
Even when the power switch is turned off, electricity is
still flowing to the product at the minimum level. When
you are not using the device for a long time, make
sure to unplug the power cord from the wall AC outlet.
Introduction
Dear customer,
Thank you for choosing Bowers & Wilkins. Please read
this manual fully before unpacking and installing the
product. It will help you to optimise its performance.
B&W maintains a network of dedicated distributors in
over 60-countries who will be able to help you should
you have any problems your dealer cannot resolve.
Environmental Information
All B&W products are designed to comply
with international directives on the
Restriction of Hazardous Substances
(RoHS) in electrical and electronic equipment and the
disposal of Waste Electrical and Electronic Equipment
(WEEE). These symbols indicate compliance and that
the products must be appropriately recycled or
processed in accordance with these directives. Consult
your local waste disposal authority for guidance.
This manual covers the ISW-4 in-wall subwoofer, its
Back Box and its matching SA250 automated rack
mount power amplifier.
Carton Contents
The product is shipped in three cartons: the ISW-4
Carton, the Back Box Carton and the SA250 Carton
In addition to the Driver Panel, check the ISW-4 carton
for:
This manual
1 x Wall Frame
1 x Grille
1 x Cut-out template
1 x Adhesive B&W logo
1 x Paint mask
6 x M5 bolts
In addition to the Back Box itself, check Back Box
Carton for:
1 x Installation Instructions
1 x Gasket roll
In addition to the SA250 itself, check SA250 Carton
for:
1 x Mains Cable
1 x Four-pole Neutrik Speakon plug
2 x Rack Mount Brackets
6 x Short Philips screws and washers
4 x Rubber hole plugs
2 x Handles
4 x Long Philips screws and washers
The ISW-4 is designed both for Home Theatre
installations and to augment the bass performance of
‘full range’ speakers in 2-channel audio systems. All
audio installations require some thought in installation
if they are to reach their full performance potential and
this manual will guide you through the process.
The SA250 subwoofer amplifier requires connection
to the mains power supply so it is important that you
familiarise yourself with the safety instructions and
heed all the warnings. Keep this manual in a safe place
for future reference.
Subwoofer Positioning
The ear poorly perceives the source location of low
frequency sound so the position of subwoofers in the
listening room is generally less critical compared to
full-range speakers. That said however, best results are
usually obtained if the subwoofer is placed between
the left and right speakers or in the vicinity of one of
them. If two subwoofers are used it is best to put one
near the left and one near the right speaker.
Locating a subwoofer on one side wall of the listening
room, even behind the listening position, is also
possible but generally results in inferior imaging. It may
be an acceptable compromise however, especially in
multi-channel AV systems, if domestic considerations
dictate.
As with all speakers, the proximity of room boundaries
affects the sound of a subwoofer. Bass volume
increases as more surfaces come into close proximity
with the speaker. Unlike full-range speakers, however,
the overall system balance can be corrected by
adjusting the volume level of the subwoofer. The more
boost gained from the room, the lower the volume
can be set and the less hard the subwoofer has to
work; but there is a down side. Subwoofers positioned
near corners often generate more low-frequency
room resonances, making the bass more uneven with
frequency.
Using multiple subwoofers in a single installation can
improve performance in the following ways:
• Maintains stereo separation to the lowest
frequencies.
• Smooth out the effects of low frequency room
resonances.
• Enable a higher maximum sound output.
In the case of two subwoofers used in a 2-channel
audio system, stereo separation will only be improved
if each channel has its own subwoofer located close to
the appropriate satellite speaker.
Subwoofer Installation
The ISW-4 in-wall subwoofer is intended for
installation within new build drywall (stud wall) or solid
construction (brick or block-work) walls. In both cases
installation must begin before plaster and/or sheetrock
7702 ISW-4 manual.indd 7
6/4/09 10:36:44
