Lets face it.  A road tunnel is a pretty horrible place to be.  They are very inhospitable, not just to you and me but to sound signals too.  The acoustic environment within road tunnels is generally very active.  Due to the internal surfaces of the tunnel, which are hard with very low sound absorption coefficients, […]

One of the major differences between a Public Address system and a Voice Alarm system is the need to monitor every part of the system for potential failure.  The most substantial and the most vulnerable part of a system is the loudspeaker circuits themselves.  There are a number of methods used by different manufacturers to monitor […]