6
8. Sand Smooth
• Sanding is the last important step before the painting begins. This can make or break the quality of the installation.
• When sanding, imperfections in the application of the joint compound may appear. If so, additional joint compound
and sanding may be needed to create a seamless transition (See Figure 9).
• Best practice may include the use of a flashlight to shine sheer light down the wall or ceiling in order to identify high/
low spots in the finish work.
9. Paint and Finish
• Once sanding is complete the face panel is ready for painting (See Figure 10).
• Prime the speaker and surrounding areas with an adhesive type of water based primer.
• Light “orange peel” texture, light knock-down texture, wallpaper, veneer, or level 5 finish may be applied.
• Heavy knock down or trowel finishes are not recommended. Conceal series speaker face panels are engineered for
optimum audio performance with no more than 1/16” (2mm) of any material applied to the surface of the speaker.
Figure 10
REPAIR & REUSE
Hairline Cracking Causes and Repair
JBL Conceal Invisible Loudspeakers are designed specifically to prevent cracking of the wallboard finish around the
perimeter of the speaker during normal use. This is accomplished by dampening the frame of the speaker from vibrations
caused during playback. By isolating the frame from vibration, movement between the speaker and surrounding wallboard
is minimized which eliminates the opportunity for cracking to occur.
If fine hairline perimeter cracking does occur soon after installation, it is most commonly associated with insufficient drying
time of the base coat of joint compound. It is critical that each coat of joint compound is completely dry when a subsequent
layer is applied. Any moisture retained in the base layer will continue to slowly dry and shrink slightly under the subsequent
layers of joint compound. This shrinking process may produce delayed hairline cracking.
This type of cracking does not typically appear at the seam between the wallboard and speaker, rather at the chamfered
edge of the speaker diaphragm about ¾" (19 mm) inward from the edge of the speaker frame. Cracking may not be visible
right away as it may take days or weeks for the base coat to completely dry.
The best way to prevent this type of cracking is to allow additional drying time for the base coat of joint compound,
especially in areas where the construction environment is cold or damp. THE USE OF HOT MUD OR CHEMICALLY
CURING JOINT COMPOUNDS IS NOT ADVISED.
Repairing this type of hairline perimeter cracking should be done with standard wall-finishing techniques:
• For smooth wall/ceiling finishes, repair usually consists of excavation of the crack using a sharp tool such as the corner
of a chisel or utility knife. Using the sharp tool, widen the crack to 1/16" to ⅛" (2-3 mm). Next fill/skim the affected area
with lightweight joint compound or spackle. Use air-dry type compounds only. Once completely dry, sand the area
smooth flat and re-paint.
• For textured wall/ceiling finishes, or finishes less critical, it is possible to repair the cracks with a water-based paintable
caulk. Using a putty knife or fingertip, push the caulk into the crack. Use a damp cloth to wipe away the excess. Allow
to dry and then paint.
TROUBLESHOOTING
Sound cuts out or is distorted
JBL Conceal invisible loudspeakers contain self-resetting limit switches for protection against excessive amplifier output.
These switches respond to the heat generated from the excessive volume output and will be triggered before output
reaches levels that could damage the speaker. Sound quality may be greatly reduced as the limit is approached but the
speaker and amplifier will not be damaged. Once fully triggered, audio output will cease until the excessive volume has
been corrected and the limit switch returns to its normal operational state (approx. 5-10 minutes).
