JBL MTC-23CM, MTC-28/25CM Installation Manual

Ceiling Mount Adapters

MTC-23CM ( for Control 23 )

MTC-28/25CM ( for Control 28 and Control 25 )

Your JBL ceiling-mount adapter allows Control Contractor Series loudspeakers to be installed
hanging down from a ceiling or beam. The adapter does not come with a base and requires the use
of your existing Invisiball base (which comes with your loudspeaker).

PARTS IDENTIFICATION: (MTC-23CM shown)

CHANGING OVER THE INVISIBALL™ BASE:

To remove the existing shaft/ball assembly from the base:

a) Loosen the nut top of the base
b) Remove the nylon insert locknut, which is on the bottom of the base
c) Pull the shaft out of the base.

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To install a new ceiling-mount shaft/ball assembly to the invisiball base:

a) Thread the plain nut (the one without the nylon insert) onto the shaft, as far as it goes.
b) Put the lockwasher onto the shaft.
c) Insert the shaft into the base.
d) Thread the new nylon insert locknut (enclosed) onto the shaft. Make sure it locks securely

onto the shaft.

e) Lower the jam nut back toward the base. Using a wrench, make sure this jam nut is

secured down very tightly onto the base.

USING THE CEILING-MOUNT BRACKET:

These brackets are designed only for mounting Control Contractor loudspeakers down from a
ceiling or beam - the shaft must hang vertically (up & down). It may not be capable of supporting
a speaker when mounted horizontally.

CORRECT

INCORRECT

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