The Hitune Bass MSB-64 (MSB-64T) two-way talk-back metal speaker column is engineered for industrial and institutional communication networks. Designed for facilities such as schools, commercial offices, and manufacturing plants, this unit facilitates both high-clarity announcements and bidirectional talk-back capability via an integrated microphone and room return call switch. Proper mechanical and electrical installation ensures balanced audio delivery and dependable signaling over 100V distributed lines.
Physical Placement and Mounting Options
The MSB-64 features a robust mild steel (MS) sheet metal housing with a black exterior finish, engineered strictly for indoor installations. Depending on architectural requirements, the unit can be configured in two distinct mounting positions:
- Wall-Mounted Installation: Affix the rear bracket assembly securely to vertical surfaces such as masonry, concrete, or interior drywall partition studs using appropriate industrial wall plugs and fasteners. Ensure the enclosure is mounted at an optimal operational height—typically between 1.5 and 1.8 meters from the finished floor level—allowing occupants easy access to the front-facing room return call switch and direct acoustic alignment with the built-in microphone.
- Tabletop Deployment: The enclosure can also be positioned on horizontal surfaces, such as classroom control desks, security counters, or administrative workstations. When placed on a tabletop, route the field cables away from moving desktop equipment to avoid strain on the terminal connections.
100V Line and Transformer Wiring
The MSB-64T variant incorporates a factory-fitted 100V line matching transformer (LMT) designed for distributed high-impedance sound systems. The speaker column operates as a passive mono reproduction unit rated at an input power of 10W RMS.
When integrating the speaker into a 100V constant-voltage public address network, observe the following electrical procedures:
- Ensure the master 100V power amplifier is fully isolated and powered down before terminating any field wiring.
- Connect the distributed audio transmission line directly across the input terminals of the 100V line matching transformer, verifying phase polarity across all parallel speaker drops on the same zone to prevent acoustic cancellation.
- Maintain calculation limits ensuring total speaker power loads on the run do not exceed the continuous output rating of the host talk-back amplifier or central console.
Talk-Back Circuit & Return Call Switch Integration
Bidirectional operation requires the termination of both the speaker audio loop and the dedicated signaling lines for the internal microphone and return call switch:
- Return Call Switch Connection: Route the signaling pair from the central talk-back console (such as the SBS series / SBS-20 master station) to the return call switch terminals. When a room occupant depresses this switch, it sends an alert signal to the master operator, indicating an incoming request to communicate.
- Built-In Microphone Path: Wire the internal talk-back microphone line back to the console's pre-amplified talk-back listening bus. Ensure low-noise, shielded cabling is utilized for the microphone return conductors to suppress external electromagnetic interference generated by adjacent industrial machinery or lighting ballasts.
Installation Specifications Reference
| Parameter | Installation Value / Requirement |
|---|---|
| Enclosure Construction | Mild Steel (MS) Metal Housing, Black Finish |
| Operating Environment | Indoor Installations Only |
| Mounting Configuration | Wall Mount / Tabletop Surface Mount |
| System Topology | 100V Distributed Line with Line Matching Transformer (LMT) |
| Input Power Rating | 10W RMS (Passive Mono Channel) |
| Console Compatibility | 100V PA Talk-Back Systems (e.g., SBS-20 / SBS Series) |
| Signaling Components | Built-in Microphone & Integrated Room Return Call Switch |
