Ampetronic dovetails into iconic HOW
Published: WORSHIP
UK: 17th Century St Paul’s Cathedral, one of London’s most recognisable landmarks, has gained a versatile Ampetronic induction loop system installed by London-based RG Jones Sound Engineering. The cathedral holds daily worship services and conducts weddings, funerals and baptisms, as well as services of celebration, remembrance and thanksgiving. Corporate events and recitals by the cathedral’s famous choir and organ are also regularly staged.
A comprehensive Ampetronic system has been installed to cover the entire floor area, plus the crypt and adjacent Chapel of St Faith, more generally known as the Chapel of the Order of the British Empire (OBE). ‘One of the key challenges was the fact that the crypt is, as you would expect, directly beneath the cathedral’s nave,’ said Jon Berry of RG Jones. ‘We discussed the issues of vertical spill and how the system could best be controlled, and the answer was a loop system divided into five zones, each zone covering a different area of the cathedral floor.’
One of the ingenious parts of the design is that Mr Berry and his team used the issue of vertical spill to their advantage. ‘When the entire cathedral floor needs to be covered, all five zones are switched in,’ he said. ‘However, the loops that cover the nave and chancel are dual-purpose, also covering the crypt and the OBE chapel. If an event is taking place in either of those areas, the inputs to the loop are switched via DSP, so users receive audio from the microphones in those areas, not from the main body of the cathedral.’ All five loop systems are switchable, with an SP5 phase shifter which aligns the middle section so that it works correctly with each of the other sections.
‘Because we obviously couldn’t disturb the fabric of the building, there were limited routes where we could run loop cables,’ Mr Berry added. ‘This meant that there were inevitably some peculiarities with the way the cable had to be run. But Tom Lane from Ampetronic came down, looked at the measurements and advised us on where we needed to optimise the loop amplifiers. The result is that there has been no compromise on the quality or strength of the loop signal anywhere in the cathedral. It’s all working very well, it’s straightforward to control and the cathedral staff are very happy with it.’