The B200S-LF-WH and B200S-LF-IV sounder bases are used with addressable detector heads. Refer to the appropriate manual for more information on sensors. The B200S-LF-WH/B200S-LF-IV low-frequency sounder base generates a low-frequency tone around 520 Hz. Studies have shown that low-frequency audible devices that operate around 520 Hz are more effective in waking individuals in sleeping areas.

The sounder base is capable of producing a variety of tone patterns, including the distinctive three-pulse temporal pattern (ANSI Temporal 3) fire alarm signal now required by NFPA 72 for commercial and residential applications. The B200S-LF-WH/B200S-LF-IV offers maximum flexibility in configuration and operation to meet or exceed the requirements of UL268 and UL464 for Continuous, Temporal 3, and March time patterns. The temporal 4 pattern meets all requirements of UL268 and UL2075, as well as private mode setting of UL 464.