ATG Danmon Completes Broadcast Audio Relay For Iconic Bell Tower

International systems integrator and broadcast systems supplier ATG Danmon has completed an audio system located in the clock tower adjacent to one of Europe’s longest established national legislatures.

The assignment was the culmination of a five-year restoration project which included repairs to the clock and the masonry of the tower itself. It allows the chimes from the tower’s five bells to be captured in very high quality for live transmission as well as for use in news programs and parliamentary broadcasts. The largest of the five, weighing nearly 14 tons, sounds the hour, supplemented by four smaller bells programmed to sound a distinctive sequence each quarter-hour.

ATG Danmon was commissioned to create the system on the strength of its experience in video, audio and IP systems design and integration for the mainstream broadcast, legislative, corporate and university-level educational sectors.

A key challenge was the need to ensure faithful reproduction of the bells with minimal intrusion from road traffic. This required relatively close-proximity microphone placement within the belfry plus the ability to handle very loud transient sound without causing distortion in the microphones themselves or in the processing electronics which they feed.

ATG Danmon designed and integrated two complete audio chains configured as a fully resilient system. At the front end of each chain are a Sennheiser E904 dynamic cardioid microphone to capture the high-level transients plus an Electro-Voice 635A omnidirectional dynamic microphones to capture the general acoustic of the belfry. All four microphones are fitted with windshields as the belfry is essentially an exterior space.

Audio output from each microphone pair is amplified to line level and encoded into an audio-over-IP data stream. All four streams are fed to a communications room where they can be converted back to analog for use with other program content or optionally forwarded via an IP link to other broadcasters.

The system integrated by ATG Danmon includes eight transceivers feeding a CTP DIO1600 AoIP interface capable of handling 16 analog line level sources and delivering 16 analog line level outputs. Each input and output allows +12 to -12 dB of gain adjustment. Operators can control parameters such as pre-amplification gain remotely via a secure IP link.

An unusual complication was the need to test the system’s acoustic and electronic performance before the date when the bells were officially permitted to resume their public duty. This was overcome by performing tests at a church with a similar clock tower. The results were successful and have since been confirmed at the actual site.

The system secured a nationwide audience at the start of 2023 when the bells were broadcast as a core element of the country’s new year celebrations.