The Barix Exstreamers decode and pass the audio to the cluster of Harman Music Group products. The first stop is a BSS London BLU-160 Series (or London BLU Series) unit for digital signal processing. Ambient noise compensation is employed to automatically adjust announcements based on the level of background noise around the local rail platform.
From there the audio is pushed into Crown CTs Series power amplifiers, with integrated Crown USP3 PIP cards to add IP intelligence. JBL loudspeakers are installed every 10 to 15 feet along the platforms. The 60-watt speakers fight the sound of diesel locomotives, which can be as high as 103 decibels at the station. The combination of the ambient noise compensation in the BSS unit and the power of the JBL speakers allow the public address system to win the battle.
“The system is programmed so that the PA turns itself down when there are no trains in the station,” said Ramsay. “When a loud locomotive rolls through, the affected speakers automatically raise the volume. This preserves intelligibility no matter what is happening on the platform.”
Rountree said that while one Exstreamer is capable of serving multiple zones, he expects to install one for every zone or platform in everyone station. For example, River Line light rail service has 21 stations; currently, that system has 21 Exstreamers, one for each station in the system.
“We considered purchasing AMX software to assign each announcement to a location, but that becomes unwieldy and time-consuming to process,” said Rountree. “The Loquendo-to-Barix sequence offers very low latency. The messages go straight to the Exstreamer. So the plan is to use an individual Exstreamer for each physical audio zone that is receiving and playing out information.”
Monetizing the Network
Digital signage is everywhere. It’s hard to think of a business vertical that doesn’t employ it in some way. Retailers, universities, stadiums, hotels, restaurants and museums are all deploying systems.
Public organizations and government are also taking advantage of digital signage’s potential, including the transportation industry.
Public safety, wayfinding and general passenger information are all merits of digital signage in rail stations. This information is being populated through a Web-based application that simultaneously publishes to the Web site. NJ Transit is taking this one step further by incorporating advertisements supplied through an outside agency.
“Our LCD displays show data scrolls on the bottom and Web pages featuring the advertisements,” said Rountree. “In selected areas we incorporate ads into the audio system through both the text-to-speech service and as our scheduled events within our background music system, which is a critical element for new revenue generation.”
Remote monitoring is a key capability of IP-based systems. Most every piece of hardware and software in the NJ Transit network is accessible from a corporate computer. This is not only convenient for general supervision but gives operators a reliable troubleshooting guide and an ability to respond quicker to performance issues.
Remote adjustments of volume and other levels can be tweaked from a distance. Ramsay specified System Architect, a software package from the Harman Group, to facilitate remote access to the processors and amplifiers.
“We enabled closed-loop station monitoring to remotely look at every aspect of the public address offering,” said Ramsay. “The London BLU-160 processors sit on the network, so we can remotely access them to look at data, confirm operation and make adjustments. There are also network devices reporting back when there are drop-outs. The PIP cards in the Crown amps, which are essentially off-board DSP units, have important remote error reporting features.”
Rountree and Ramsay worked up a unique idea for verifying live audio quality at distant locations. A Barix Instreamer 100 encoding device is attached to an auxiliary output on every BSS processor, capturing live audio picked up by ambient noise sensing microphones on each platform. The Instreamer encodes the audio and streams it to offices where operators can confirm signal intelligibility on the spot and send test signals as necessary.