Case study – Fohhn brings a new sound to Sheffield’s St Marie Cathedral

Audio meets architecture as new sound system featuring loudspeakers from Fohhn is installed during cathedral renovation programme. TFA looks at the considerations. Fohhn loudspeakers and multi-channel DSP amplifiers have formed the backbone of a new audio system installed in the Cathedral Church of St Marie, Sheffield, during a major programme of renovation. The system was designed and installed by Wigwam Acoustics, with the loudspeakers and amplifiers supplied by Fohhn’s UK distributor Systems Workshop.
In addition to its regular programme of services, the cathedral hosts a number of concerts and recitals each year. A versatile loudspeaker system capable of delivering both high levels of speech intelligibility and dynamic reproduction of music in an acoustically-demanding environment was therefore an essential requirement. The cathedral is also a listed building whose architectural features and finely decorated interior brought other challenges to the project. The Wigwam installation team carried out several on-site demonstrations before Fohhn Linea Series LX-100 loudspeakers were ultimately selected for their sound quality, directionality and elegant yet unobtrusive appearance. The German manufacturer’s compact two-way line source system combines eight 4-inch neodymium drivers and a 1-inch compression driver with Fohhn Waveguide. Speaker adjustment is via an integrated crossover with Intelligent Protection Circuit (IPC) to guard against overload.@page_break@Reverberation proved a major acoustic challenge, as in all cathedrals, so a distributed, time-aligned loudspeaker system was implemented to ensure even coverage and maximum clarity throughout. Four pairs of LX-100 loudspeakers were mounted to pillars covering the nave and side aisles, with two additional LX-100 systems targeting the north and south transepts. Two further LX-100 systems were installed for coverage of the chancel, while two Fohhn Arc-Series AT-09 loudspeakers were provided for the dais area. Two Fohhn D4.750 DSP-controlled Class D amplifiers were installed to control all the loudspeaker systems. The loudspeakers were also required to visually blend with the interior, so Wigwam worked closely with the cathedral architect to carefully colour match all loudspeakers and cabling to the fabric of the building. Custom brackets were also designed enabling the LX-100 systems to be mounted as closely as possible to the surface of each pillar in order to appear unobtrusive.
Various control systems were implemented to enable simple operation of the audio system on a daily basis by cathedral staff – another important requirement of the installation brief. “The feedback received from cathedral staff, musicians and congregation members about the sound quality of new audio system has been extremely positive,” said Tim Mortimer, installations manager at Wigwam Acoustics. “The cathedral artist has also commented on the visual impact to the building, stating that the loudspeakers and painted cabling have blended in excellently. The architect is very pleased with the overall results too. From the initial concept and design by Mick Spratt and myself to the final installation by David Orridge and the site team, it couldn’t have gone any better, despite the various challenges involved.” www.fohhn.comwww.wigwamacoustics.co.ukwww.systemsworkshop.com