Feature: Centre of excellence
Feature: Centre of excellence
The Bangalore International Centre (BIC) has moved into new premises, with acoustic design by Sound Wizard, and Nova and QSC systems throughout. Caroline Moss reports
BIC was founded in 2005 by a group of civic leaders, professionals, artists and academics who believed the capital city of Karnataka state deserved a forum for intellectual pursuits, arts and culture. A non-profit institution supported by membership and donations, BIC was inaugurated by former Indian president, the late Abdul Kalam, and was previously hosted by the Energy Resources Institute. Earlier this year, BIC moved just around the corner into new 14,600m2, GRIHA (Green Rating for Integrated Habitat Assessment) premises of its own.
Fortunately for Sound Wizard, which was appointed to provide acoustic design services for the new building, BIC’s evident foresight in envisioning the new facility extended to the planning required for its construction.
‘We were contacted by BIC about three years ago; they called us early on in the project so we could get involved with the acoustics,’ explains Didier Weiss, founder of Sound Wizard, which is headquartered in the neighbouring state of Tamil Nadu. ‘The architect, Bijoy Ramachandran, founder of Hundred Hands, is someone we’ve worked with on other auditoriums in the past, so he was pretty open to our suggestions and that helped a lot.’
Seven years in the planning, the new building was funded entirely by donors and members. Sound Wizard worked on acoustic design for the 180-seat auditorium, a large seminar hall, meeting and video conferencing rooms, an art gallery and cafeteria.
For the thrust-configuration auditorium, which has been designed to function as a largely acoustic, multipurpose space, the company conceived and manufactured a range of microperforated panels of differing types. ‘The requirements for amplified and acoustic performances are in direct conflict,’ explains Sound Wizard’s Bangalore-based acoustic engineer, Rahul Sarma. ‘Acoustic performances require an amount of reflective surfaces in order to naturally amplify sound within the space.’
Hundred Hands conceptualised a multifaceted, single-surface interior shell, which creates variably spaced air gaps throughout the auditorium, providing effective absorption across all frequencies and allowing it to function as a multipurpose venue.
‘This solves a common issue in auditorium designs where a fixed air gap from a simple rectangular box results in excess absorption at particular frequencies,’ continues Sarma. ‘Using perforation on the inner wooden shell allows acoustic absorption to remain hidden. Varying the perforation allows mid- and high-frequency energy to be reflected and carried throughout the room, while allowing low-frequency energy to still pass through the shell and be absorbed. This might result in a slightly higher reverberation time compared to the average auditorium, but the main benefit of this design is the ability for unamplified sound to carry through the space.’
Sound Wizard used EASE software to design the sound system, placing speakers on the stage at human head height to simulate people talking, singing or playing an instrument onstage. The angles of the wall and ceiling panels were adjusted and angled to reflect the sound created onstage. After many iterations involving input from the architect, the overall geometry of the space was finalised. From here, the amount and location of perforation in the various panels had to be determined. By differentiating between the first reflection points of the auditorium line array and the ‘speakers’ placed on the stage, Sound Wizard was able to identify the useful and harmful reflections in the auditorium by analysing the bounces on the walls and ceiling. The useful reflections were guided with reflective surfaces with little to no perforation, and the harmful reflections from the line array were treated with highly perforated panels.
‘We were aiming for a perfect integration between natural acoustics and electro-acoustics in our design,’ says Sarma. ‘Sound system integration has been designed as an enhancement of natural acoustics, using a combination of both.’
As the auditorium has been designed to function as an acoustic space, the technology installed has been kept to a minimum. Two small, powerful Maxline M5 boxes from German manufacturer, Nova, have been installed as an L-R system in the auditorium. Sound Wizard chose Nova systems for the auditorium and seminar hall, and also for a portable system, and all were supplied by Rivera International, the manufacturer’s Mumbai-based Indian distributor. The Maxline M5 combines six 5-inch transducers in a line array arrangement with a midrange horn and three Beyma drivers with 1.75-inch voice coils, in a cabinet which is just 53cm high. ‘The small boxes are amazingly powerful, and they also meant we could keep the sightlines clean,’ says Weiss. ‘This is the first installation I’ve done with the M5; I really love working with small drivers because the impulse response is so good.’ Two Nova E218 subwoofers extend the system’s frequency range, providing a transparent system for multipurpose applications.
The stage is around a third of the size of the auditorium itself. ‘They’ve designed it this way as they anticipate the hall to be used in between performances as a rented rehearsal space for bigger shows,’ says Weiss. ‘The stage is as big as one found in larger theatres, so there is room to rehearse the entire production and carry out dress rehearsals.’
In addition to cultural programmes such as music, film and drama, this versatile space can also be used for training sessions, panel discussions, product launches and other corporate events.
Sound Wizard also worked extensively to provide solutions for HVAC silencing to cut down on background noise from air conditioning and other sources, while avoiding surface rattling. The auditorium noise floor has been measured and certified as NC25.
The building has been designed to work on a QSC platform, with QSC Core 110f processors installed in the auditorium and seminar hall, respectively. There is a QSC TouchMix-30 Pro 32 channel mixer in the auditorium and a QSC TouchMix-16 16-channel mixer in the seminar hall for FOH control. Both DSPs can be controlled by a custom-designed interface on an iPad that gives easy and intuitive control over various functions, including simulcasting.
All integration was handled by local SI company, Flamenco Tech. ‘The requirement was to send every signal between every room in the building through Dante, using a scalable WyreStorm network so that a conference in the auditorium could be viewed and listened to in the different meeting rooms and the upstairs terrace,’ continues Weiss. Currently, however, only the seminar hall and auditorium are connected, allowing simulcasts between the two spaces. When large events are held in the auditorium, a spillover crowd can be accommodated in the seminar hall, who will be able to follow the action on a projection screen. The QSC platform also allows audience members in the seminar hall to pick up a mic and ask questions to speakers in the auditorium, effectively allowing the spillover crowd to interact effectively with presenters in the auditorium. Eventually, this interconnectivity will extend across the entire building.
In addition, Sound Wizard provided acoustic consultancy for the centre’s seminar hall. This can be divided into two spaces to accommodate 60 and 80 guests, respectively, by removing a concertina partition. Modern, configurable furniture adds to the flexibility of these rooms, which have been designed for seminars, workshops, meetings and social gatherings. A Nova Europa 601 system comprising two EX601 compact array speakers, and an M318SUB active subwoofer which handles speaker management, have been provided for this hall.
‘They wanted to have a clean space without too much investment, so here we’ve carried out some acoustical treatment on the ceiling and walls,’ says Weiss. This consists of fabric-wrapped wood wool cement board – mounted with an air gap and polyester fibre insulation – helping to absorb more than just speech frequencies. ‘There is a Dorma partition to make two independent rooms, so the audio system can be split if there are two functions, and the isolation is fine for conference purposes,’ he continues. ‘As we’ve used the Q-Sys platform, all the mics and equipment can be reassigned to wherever it’s needed, and the iPad presets we’ve provided make it simple to operate.’
Rivera International also supplied six Nova Mythos 12 self-powered two-way speakers. These can be used as monitors in the auditorium and the seminar hall, and also as a portable system for the open-air roof terrace and throughout the building as and when required, for example for informal events that are often held in the foyer.
For the rest of the building, the acoustic intervention was minimal. All spaces that have loudspeakers have been decorated with custom-designed ceiling acoustic treatment: plywood frames stuffed with polyester fibre absorption and held in place with acoustic felt on the bottom. These boxes, which are used throughout BIC, also house recessed lights in most areas. ‘While primarily designed with aesthetics in mind, they also do a good job of absorbing speech frequencies,’ says Sarma.
QSC AD-C6T-LP ceiling speakers have been installed throughout the cafeteria, classroom and art gallery. All these rooms have local control for now via Yamaha MG06 mixers, but can be connected to either of the Core 110f units to allow central control. Sennheiser EM 100 G3 wireless microphone systems with SKM 100 handheld mics have also been provided.
With the creation of BIC, Bangalore’s business, art and academic communities have surely been rewarded with the forum they have long felt they deserved.