PAGE
7
S
ection 2
•
T
erminating the wiring
2.2 Locating the speaker
positions in each zone
Unless the cables for the ceiling speakers
have been left hanging out of the ceiling
(as is common with light fi ttings), it will
be necessary to locate these positions.
The easiest way is to refer to the marked-
up position of the speakers in the plan of
the home. This should have been done as
part of the fi rst fi x installation. If that is not
the case, the following method should be
used to trace the position of the cables.
Locating concealed cables
A Cable Tone Test set, available from
electrical wholesalers, can be used to
locate concealed cables.
Connect the tone generator to the cable
being tested at the hub location (noting
the correct label for a given room; see
Wiring schedule
in the
Systemline
Planning Guide),
and move the probe
over the ceiling of the selected zone room
until the tone reaches its peak sound level.
The cable should be directly above the
plasterboard at this point.
Note:
The above cable tracing technique
will not work with foil-screened stud
walling, metal wall tiles or ceiling panels.
It is recommended that you tackle one
zone room at a time.
Once the speaker positions have been
located and marked on the ceiling by
way of a cross, check the following
considerations. Remember also, that
for some small rooms such as ensuite
bathrooms, only a single mono speaker
may have been provided for.
Clearance
Drill a small diameter hole in the ceiling at
the marked point and check, using a thin
screwdriver or thin rod as a measuring
tool, that there is at least 90mm depth
from the front surface of the ceiling to the
back.
In the very rare instance that there is
insuffi cient depth, the speakers can be
mounted protruding below the ceiling
using a suitable spacer. For more
information contact QED Audio Products
Ltd.
Beware of joists
Make up an L-shaped test probe using stiff
metal wire or a bent screwdriver. Check
that there is suffi cient clearance to cut the
correct diameter hole out of the ceiling. If
during this test the L-shaped probe hits a
joist, drill a second hole close to the fi rst
one, but over to one side away from the
joist.
Note:
At this point you should be able to
detect the presence of the CAT5/6 cables
(indeed, these may interfere with your
ability to spin the L-shaped tool around).
Repeat the test to confi rm clearance.
L-shaped probe dimensions:
100mm (3.75")
L-shaped probe is obstructed by the joist:
Probe confi rms that by using the revised
centre hole, that the 195mm dia hole can
be cut without hitting the joist:
Once the correct position has been
identifi ed, use the template provided and
mark in pencil the correct 195mm (7.75")
diameter hole on the ceiling.
Warning:
Please ensure that the ceiling
can withstand the weight of the speakers.
