Bowers & Wilkins CWM3 Speaker User Manual


 
6. Using a Back-box Kit
Custom install back-box kits comprise a re-proof
box that can be tted behind in-wall or ceiling
speakers before the sheetrock (plasterboard) is tted
to the studs (joists). As well as enabling compliance
with re regulations, back-boxes also help optimise
speaker performance by providing a dened acoustic
loading volume. A minimum clearance depth of
90mm from the outer stud (joist) plane to any rear
obstruction is required to t a back-box.
Back-boxes incorporate holed side anges that are
intended to be nailed to adjoining studs (joists). All
the nail holes should be used to help minimise the
risk of the ange vibrating against the stud (joist)
when the speaker is in use.
Speaker cable is bought into back-boxes via sealing
glands. Once the cable has been brought through
the gland, and the gland tightened, re-retardant
sealing mastic should be used to seal the assembly.
Ensure that a generous length of cable is available
in the back-box before the gland is sealed. A cable
clamp adjacent to the gland provides cable strain
relief.
When the sheetrock (plasterboard) is tted over the
back box a generous bead of re-retardant sealing
mastic should be applied to the back box anges
in order to seal the assembly and minimise the
possibility of vibration when the speaker is in use.
Diagrams 10-12 illustrate back-box installation.
6
ENGLISH
Diagram 10
Back-box stud (joists) installation
Diagram 11
Cable installation
Diagram 12
Sheetrock (plasterboard) installation