The centrepiece of the building is the Grand Temple which has recently had an Ampetronic induction loop fitted by Surrey-based contractor Scanaudio.
As well as the main 'floor', the Grand Temple features a balcony on three sides and the Ampetronic system, powered by a pair of ILD1000G loop amplifiers via an SP5 phaser, was required to cover the whole chamber and to meet new British Standard requirements for induction loop installations.
However, discreetness was imperative because of the sensitivity of the fine architecture and the fact that, as well as Masonic meetings, the Grand Temple is used for a range of other functions including filming contracts.
"The Grand Lodge is one of finest art deco buildings in London, so we had to be extremely careful," says Scanaudio's Dee Couchman. "It was made even more challenging by induction loops not even being invented when the building was originally constructed, so of course they didn't allow for them in the infrastructure."
Ampetronic took on the challenge of designing a system that ensured maximum coverage, but made as little impact as possible on the fabric of the building. "Structural metalwork invariably has a significant negative effect on loop performance", says Ampetronic's James Bottrill. "Bearing in mind the restrictions placed on installation locations by the ornate architecture, and knowing that Freemason's Hall is a steel-framed structure with concrete floor slabs throughout, a site survey was considered essential if an acceptable result was to be assured. The data collected on site enabled us to design a system which would assure good performance, whilst minimising the complexity of the installation."
"We used a combination of copper tape and 2.5mm.sq cable, which was necessary because of the restricted access to the under-carpet areas, so we could discreetly glue or stapled cable in some areas," says Couchman.
With the loop amplifiers installed in an existing A/V equipment rack, the only part of the Ampetronic system that is visible is a 1m length in an unobtrusive plastic extrusion, which links the balcony loop to that on the floor of the hall.
Feeds for the induction loop come from the Grand Temple's installed audio system, which comprises wired and radio microphones, an auto mixer and compact loudspeakers.
"The combination of a suitable microphone scheme and a carefully designed and installed induction loop system will be of great benefit to hearing aid users attending functions in this spectacular building," concludes Bottrill.
(Jim Evans)
