A critical success

Consistently ranking number one in Asia and 10th worldwide in the QS World University Rankings, the Hong Kong Academy for Performing Arts (HKAPA) has established itself as a premier educational institution. Dedicated to nurturing professional artists in Chinese opera, dance, drama, film, television, music, theatre and entertainment arts since 1984, the Wan Chai landmark has managed to retain some of its talented alumni including Sanco Lee and Lee Hoi-Fai, who have worked in the venue’s technical office for 32 and 15 years, respectively, after graduating. Having recently instigated a major audio upgrade for the amphitheatre, their intimate knowledge and first-hand experience of working in this venue proved to be crucial in its next-stage evolution.

As the chief sound technician of HKAPA’s technical department in 2010, Lee Hoi-Fai witnessed the conversion of an open-air concrete amphitheatre into a comfortable 600-seat indoor performance space. Retaining the feel of the original outdoor amphitheatre, the venue was reshaped and enclosed under a glazed space frame roof with motorised blackout blinds. Optimising the acoustics for spoken word, drama and music, 16 reversible hinged panels were installed around the rear of the auditorium. Designed by architectural company the Oval Partnership, the classical seating layout provides excellent sightlines and an intimacy with performers on the large stage, which is level with the lower rows of the audience area.

Powered by four d&b audiotechnik 40D amplifiers, the L-C-R solution incorporates four CCL12 cabinets and a CCL-SUB for each hang. To match the existing steel column structure, a custom RAL colour finish was also specified. “We highly valued the opportunity to manage the first deployment of a customised CCL array here in Hong Kong,” says Lee Hoi-Fai. “It ticks all the boxes in terms of coverage, SPLs, the cardioid pattern for directing the sound energy towards the audience area and the reduction in sound reflections from other areas in the venue. In addition, the stage area is quiet now because the CCL’s sound energy is directed towards the front.”

The auditorium has of course experienced other technological upgrades since the Qi7 system, including the addition of a Yamaha console. Further works are being planned, including an active acoustic system for enhancing orchestral performances.

As the amphitheatre continues to stage the next generation’s top talent, HKAPA continues to be regarded as a recognised hub for regional artistry by elevating their performances. Appearing beneath 15 fixed cabinets discreetly integrated into the ceiling, artists may leave the stage without remarking on the sound. Yet the clarity, from the drop of a pin to the sustained resonance of a cello, will not be lost on performers or audience alike.

Since the transformation, a d&b audiotechnik Qi7 loudspeaker system has faithfully served the requirements of this significant venue. “I find d&b to produce a big, clear and powerful sound, but it’s also quiet where it needs to be,” commented Lee Hoi-Fai at the time. “We selected d&b as it demonstrated all the necessary criteria: natural sound; light, compact cabinets; and a rigging system that is safe, easy and swift to install, especially for flown arrays. The system is multichannel and designed to provide smooth and even coverage. We were confident that it would provide us with the high-powered natural audio and music reinforcement that we required.”

However, 15 years and countless performances later, Lee Hoi-Fai is inspired to provide a more balanced assessment. “Consisting of three Qi7 speakers in a central cluster on the top and two Qi7 enclosures per side in stereo behind the projection wall, the d&b audiotechnik setup has served us well on an almost nightly basis since 2010,” he asserts. “However, the point source speakers were starting to degrade slightly, and some performers were experiencing difficulties with microphone handling and feedback from the top of the stage and from behind. When the microphones were deployed on orchestral performances, they picked up sound emitting from the speakers. Furthermore, during a solo, there would be feedback when using a clip mic, so we started to think about how we could overcome these problems.”

Ruling out initial consideration for a spatial audio solution on account of the room’s architecture, HKAPA focused on improving the reinforced audio for the audience. The academy’s technical team once again turned to the expertise of d&b audiotechnik Greater China, which applied ArrayCalc modelling to simulate optimum audio levels for both audience and performers. By minimising reflections returning off the rear auditorium walls towards the stage, the sound energy levels have been focused within the auditorium. Meanwhile, d&b audiotechnik’s newly launched CCL (Compact Cardioid Line) passive cardioid speaker system was proposed as a solution to ensure cancellation from the rear of the speakers. The first model in the manufacturer’s new CL (Cardioid Line) Series to be rolled out, the CCL array combines broadband directivity control with low-frequency cardioid behaviour. Enabling single-channel amplifier operation, the passive speaker system features a revised implementation of d&b’s patented design to bring cardioid directivity and electroacoustic performance to smaller audience areas closer to the stage.

Comprising two 7-inch front-firing drivers, two 5-inch side and rear drivers and two 1.75-inch high-frequency transducers, the electroacoustic design combines low-frequency and broadband directivity control with high-frequency headroom and minimal distortion. It is available in 80° (CCL8) and 120° (CCL12) horizontal dispersion versions. The CCL speakers installed at HKAPA measure 209mm x 593mm x 355mm and weigh 18kg. The flyable CCL-SUB passive subwoofer, which offers reduced port noise and extended usable bandwidth, features a front 15-inch and a rear 10-inch driver configuration.

The CCL’s specifications ticked all the boxes for the venue’s requirements. “The Qi7 point source series worked well for 15 years, but had some limitations,” admits d&b audiotechnik Greater China sales manager, Mark Lee. “With the stage being connected to the audience area, the audio demands intelligibility together with even, high SPLs, but without affecting the performers onstage. In addition, the unique semi-circular audience area required careful loudspeaker placement.”

A steel column structure fixed to the ceiling offered little space for hanging loudspeakers, posing a problem for deployment. “To attach the arrays to the steel column, customised mounting was required, meaning that the whole array would need to be panned and tuned at an optimum angle to maximise the coverage throughout the audience area,” he continues. “There was also a safety issue to consider, because the steel structure is not attached to an overhead slab of concrete and so the mounting would need to be secure enough for loading this weight.” With the problem identified, a structural engineer was commissioned to calculate that the loading was safe before commencing with the custom mount shipping. “Following modelling and ArrayCalc software simulations, we concluded that an L-C-R solution would work best because a stereo system would not provide sufficient coverage for the three audience areas,” Mark Lee explains. “ArrayCalc confirmed that the L-C-R deployment would provide excellent SPL coverage throughout the venue.”