Tannoy in wall Owner's Manual page 8

NOTE
SPEAKER LOADING VOLUME
There are two simple approaches to achieve a sealed 'enclosure' to provide the correct driver loading area behind the speaker. The chosen
method will depend on whether the wall is under construction, as in a new building project, or an existing wall where access is limited.
Option 1
Stud partition walls under construction, with 102mm by 51mm (4 by 2 inch) timber at 406mm (16 inch) centres.
Block off the cavity, above and below the intended speaker opening, with the same framing timber. The distance that these two internal
barriers should be separated by is shown below in Fig 1.
If the stud centres are greater than 16" apart then insert two timbers vertically between the blocking timbers to create the desired loading
volume. See Fig 2.
System
Separation mm (inches)
INSIDE STUD PARTITION
VIEWED FROM REAR
Option 2
Existing timber stud partition, or any other wall type with constructed with a 406mm (4 inch) cavity depth.
Many professional installers use a 'doughnut' of compliant material, which can be inserted as a tight fit between the two surfaces
of the partition or into the wall cavity. The length of the internal surface of the strip of material determines the 'enclosure' volume.
Cutting the strip to the length shown below and joining to form a ring will ensure the correct volumes.
System
Separation mm (inches)
INSIDE WALL VIEWED
FROM REAR
FIG 3 STUD PARTITION OR WALL CAVITY USING
8
iw6 DS iw6 TDC
410 (16)
FIG 1 STUD PARTITION UNDER CONSTRUCTION –
16" TIMBER CENTRES
iw6 DS iw6 TDC
1380 (54) 1570 (62)
COMPLIANT MATERIAL OF APPROPRIATE
THICKNESS TO CREATE TIGHT SEAL
550 (21.5)
NEW TIMBER TO
CREATE ENCLOSURE
EXISTING TIMBERS
BACK OF SPEAKER
INSIDE STUD PARTITION
VIEWED FROM REAR
FIG 2 STUD PARTITION UNDER CONSTRUCTION –
TIMBER CENTRES OVER 16"
'DOUGHNUT' OF
COMPLIANT MATERIAL
BACK OF SPEAKER
NEW TIMBER TO
CREATE ENCLOSURE
EXISTING TIMBERS
BACK OF SPEAKER