Transit Paging System

Will Fraser

Transit Paging System

The audio design for a transit paging system has a number of unique requirements, including:

~ Flexible page routing to multiple zones.
~ Paging priority.
~Comprehensive Interface with paging controls and system monitoring.
~ Multiple zones of Ambient Noise Compensation for each platform.
~ Safety Announcements and Background Music inputs.

In this design we use HiQnetTM London ArchitectTM running on a touch screen as the control interface. This gives the operator an intuitive method for viewing the system status and selecting zones for paging. By selecting the station from the list on the left of the interface, the Operator can adjust the levels in each zone and view the ambient levels in that station.

Indicators next to each station name show if a local page is active. The buttons on the top of the interface allow the Operator to select individual platforms or combinations of platforms for paging. By utilizing Push To Talk (PTT) microphones and the control ports on the SoundwebTM London devices, logic objects can be used to reset the paging zone selection at the end of each page.

By using the Ducker processing object, a true override paging system has been designed that will automatically “duck” the background music (reducing it in level by a prescribed amount), so that announcements can be clearly heard above the level of the music. Upon completion of the announcement, the background music is automatically restored to its previous level. By using cascading Duckers we can create Priority in the signal routing. Announcements will duck the BGM and any local page will duck announcements and BGM. Any pages from Dispatch will duck announcements, BGM and local pages. The closer a Ducker is placd to the output the higher priority that signal has.

Each station has a BLU-120 for local page input, ambient microphones and outputs to the amplifiers for that station. Each BLU-120 sends its input signals across the digital audio bus to the BLU-160 for processing, then back across the digital audio bus to the BLU-120 for output to the amplifiers. Additional sources, and output zones can be added to the system if you choose by adding additional BLU-120s connected with the digital audio bus.

BSS Audio’s digital audio bus is found on all BLU-800, BLU-160, BLU-320 and BLU-120 devices. It carries 256 channels of audio at 48kHz, and 128 channels at 96kHz, both at 24bit across a standard CAT5e connection between devices. When connected in a loop, it has redundancy, allowing any one digital audio bus cable to break while still maintaining audio. The digital audio bus devices are connected ‘point to point’ eliminating the need for expensive switches. You can have up to 32 digital audio bus devices and one Cobranet network connected together allowing you to split and route multiple signals to multiple locations simply by adding more BLU-120s to the network.

>>>Click here to download the full application guide and sample file.<<<


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BSS Audio
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