d&b PA solution suits reverberant concert hall31 October 2017
A new PA system from d&b audiotechnik has equipped the main concert hall at the Lighthouse performing arts centre for the increasingly diverse range of events that it hosts.
Lighthouse is the cultural hub for both the seaside resort of Poole and its surrounds. Opened in 1978, it was originally conceived as the new home for the Bournemouth Symphony Orchestra and as a multi-space venue for Dorset and the further reaches of the south-west UK. Inside the complex is a central concert hall, a mid-size theatre, a small-scale studio theatre as well as a cinema, art galleries and function room facilities. As the name suggests, Lighthouse provides a beacon for all performance arts.
The decision was made to replace an ageing and inadequate audio system in the main concert hall, as Jake Sutton, technical manager at Lighthouse explained: “The system we had in place was really only suitable for public address and simple amplification for events. We augmented this for music and other performances that required more audio support but it was very hard work to get an acceptable sound. Our main issue was lack of direct speaker coverage and uniformity of sound across the whole auditorium. We, alongside theatre consultants Charcoalblue, invited three PA companies for a speaker shoot-out in the concert hall.
“As home to the Bournemouth Symphony Orchestra, the hall has an acoustic which is well suited to classical performance; however the programme for Lighthouse concert hall has seen an increase in speech-orientated material in recent years. The longer reverberation time lends itself to symphonic music but causes issues for speech intelligibility so this needed to be addressed through a new loudspeaker system. The guys from d&b really understood our challenge. They talked us through the various options and advised on best performance. It was a really smooth outfit from the moment they pulled up to leaving the venue.”
The project was tendered out to Complete Production Solutions (CPS), which has a long association with both Lighthouse and d&b. Sutton continued: “CPS are our main hire company; we use them for dry hire of steel deck, radio mics, screens and the like. In the last five years they have taken on our technical maintenance contract, providing support and servicing of our kit and systems, so it was a logical option to use them for the install.”
Based on the venue’s requirements d&b suggested a system of primarily Y-Series arrays, driven by 30D and 10D installation amplifiers. Adam Hockley of d&b GB’s technical sales team adds the detail: “The new system needed to be able to handle every programmed event from spoken word to live contemporary music, so our approach was a line array which exhibits greater vertical directivity and a higher output than the point source alternative.
“Using ArrayCalc, we calculated that an array of Y-Series loudspeakers, with a combination of the narrow dispersion Y8 and the wider dispersion Y12 cabinets at the bottom of the array, would allow us to deliver broadband signal to the entire audience area with minimal level variation. The eight deep Y-Series array achieves vertical pattern control to around 170Hz whilst the dipolar driver arrangement gives us horizontal pattern control to 500Hz. This means that we are delivering as much of the energy to the audience as possible with much less hitting the ceiling and side walls and being reflected back into the audience. This later arrival usually adds to the reverberant field and would have a detrimental effect on speech intelligibility.
“The Y-Series arrays were supplemented by E-Series’ E8 frontfills which help to cover the first couple of rows of the audience whilst also bringing the audio image back down onto the stage from the flown arrays for those sat nearer the front of the auditorium. No full range system is complete without subwoofers to deliver the real low end; here it was requested that the subs be stacked left and right on the stage so we suggested V-SUBS as the max SPL of a V-SUB is higher than a Y-SUB. This means we require fewer V-SUBS to achieve the appropriate level, to combine with the Y-Series tops.”
The new installation has been hard at work since completion. Sutton concluded: “It was great to work with the teams from CPS and d&b – people who were as enthusiastic as we were on getting the very best result. We use the system for all types of events, music, comedy, literature events and dinner dances and it performs superbly across all genres. We’ve received loads of excellent audience feedback on sound quality via the Purple Seven website, as well as real positives from visiting FoH engineers who have generally just left their FoH PA out in the truck.”
(Picture: © Jim Stephenson 2017)