JBL – CBT 70J-1

The MTC-CBT-70T is an essential bolt-on transformer module designed to enhance the versatility of JBL’s CBT 70J-1 and CBT 70JE-1 loudspeakers, as well as CBT 70J-1/JE-1 arrays, by enabling them to be used in distributed loudspeaker systems. This module facilitates the use of long cable runs and the connection of multiple speakers from a single channel on a distributed system amplifier, making it a valuable tool for complex audio setups where scalability and flexibility are crucial.

Key Features and Functionality:

1.Distributed System Adaptability:
– The MTC-CBT-70T transformer module is specifically engineered to adapt CBT 70J-1 and CBT 70JE-1 loudspeakers for integration into 70V and 100V distributed loudspeaker systems. This allows for long cable runs, making it possible to drive several speakers from a single amplifier channel, thus simplifying system design and installation in large or challenging acoustic environments.

2. Transformer Taps:
– The module offers multiple transformer tap options to accommodate various power needs and system requirements. It includes taps for:
– 120W
– 60W
– 30W
– Additionally, there is a 15W tap available specifically for 70V systems.

These tap settings provide flexibility in matching the power requirements of the loudspeakers to the distributed amplifier output, ensuring optimal performance and efficient power distribution.

3.Connections and Wiring:
Connections are made using customer-supplied cables, which are attached to screw-down terminals inside the module’s enclosure. This design provides a secure and reliable connection method.
The module is equipped with two gland nuts:
One gland nut is used for the cable entering the enclosure from the amplifier.
The other is for the cable connecting the terminal strip to the loudspeaker’s input terminal.
The gland nuts form a watertight seal when used with round jacketed cables with an outside diameter ranging from 4.0 mm (0.16 in) to 9.0 mm (0.36 in), ensuring durability and protection against environmental elements.

4. Tap Selection:
Tap selection is straightforward, achieved by connecting the cable from the power amplifier to the appropriate terminals on the internal terminal strip within the module. This allows for quick adjustments and precise matching of power levels according to the system’s needs.

5. Mounting and Installation:
The MTC-CBT-70T is designed for easy mounting. It features mounting holes that fit two 6 mm screws, allowing the module to be securely attached to any of the side-by-side insert points located on the back of the CBT 70J-1 or CBT 70JE-1 cabinets.
This mounting flexibility ensures a stable installation and integration with the loudspeakers, minimizing installation time and effort.

The MTC-CBT-70T transformer module’s robust design and versatile features make it a crucial component for distributed audio systems. By providing options for power tap selection, secure wiring connections, and straightforward mounting, this module enhances the functionality of JBL’s CBT 70 series loudspeakers, making them suitable for a wide range of applications including large venues, commercial installations, and public address systems.