Extension to EVAC horn loudspeaker range

13 April 2006

Germany - Bosch Security Systems has added a 50-W (rated power) model to its range of high-efficiency, EVAC-compliant horn loudspeakers. The new model, the LBC 3484/00, is specially designed for use in public address and voice alarm system applications that require a high level of sound pressure, such as industrial sites and sports grounds.

All three speakers in the range (490 mm/50 W, 490 mm/35 W and 355 mm/25 W) are robustly constructed in corrosion-proof aluminium with a PVC edge profile for protection against impact damage. With a maximum power output of 75 W, the LBC 3484/00 employs a high-efficiency driver that provides excellent sound reproduction. The loudspeaker is also available as separate horn and driver to allow a choice of combinations when installing.

The new loudspeaker has provision for incorporating circuit boards for Bosch's Plena and Praesideo Voice Alarm Systems. The Plena End of Line (PLN-1EOL) supervision board detects the 20 kHz pilot tone on the loudspeaker lines. If a fault occurs, a signal is sent as a fault output to the appropriate system control unit. The Praesideo Multiple Line and Loudspeaker feature enhances the safety and security of the voice-alarm system by monitoring the correct functioning of individual loudspeakers and loudspeaker line branches. Both the Plena and Praesideo features allow security and emergency staff to immediately identify malfunctioning loudspeakers or line breaks. This permits fast corrective action and ensures increased safety.

Other features of the LBC 3484/00 include built-in protection against fire to ensure system integrity by incorporating a ceramic terminal block with thermal fuse and heat-resistant wiring. A provision for loop-through cabling makes easy and quick connection of multiple speakers possible. The matching transformer has three primary taps that allow selection of power radiation in three dB steps (12.5, 25 and 50 W).

Maximum quality is maintained through compliance with IEC 60268-5 Power Handling Capacity (PHC) standards that require the loudspeaker to operate continuously at rated power for 100 hours. Moreover, Bosch's Simulated Acoustical Feedback Exposure (SAFE) test demonstrates that the loudspeaker can withstand operation at twice the rated power for short durations. This ensures reliability in extreme conditions, extended product life and reduced incidence of failure or performance deterioration.

(Chris Henry)