ICE Design Australia
Acoustic Directions now undertakes parliamentary projects as part of it’s sister company, ICE Design Australia. Please go to www.icedesign.net.au for more information.
Northern Territory Parliament
During 2011, ICE Design undertook the design and commissioning of a new highly-engineered and bespoke sound system for the Legislative Assembly chamber floor and public galleries. Comprising of multiple beam-steered array elements, each loudspeaker provides ultra-consistent coverage, voice naturalness, and high gain before feedback. The total system provides exemplary intelligibility and sound naturalness. Included in this work was room acoustic treatment to eliminate echoes, and our acoustics laboratory was used to test the acoustic properties of various fabrics and materials to ensure they met our requirements.
Recently, ICE Design designed and commissioned new sound reinforcement and recording systems for the Litchfield Room – the Parliament’s main committee room. The work was done under extreme time pressure and delivered a flexible, ultra-intelligible and appropriate solution for the Parliament.
New Zealand Parliament
ICE Design was responsible for the implementation of a new bespoke sound system with integrated control system for the Debating Chamber. The team provided comprehensive services from the project inception in 2006 right through to the extensive commissioning period during late 2008.
ICE Design undertook a comprehensive systems and procedural audit, and subsequently developed the replacement audio and control systems to meet the specific needs of the Parliament.
Working closely with heritage consultants and the project architect we developed a range of bespoke loudspeaker types that simultaneously addressed strong architectural and acoustic requirements. In response for the need for ultra-high speech intelligibility in the strongly reverberant nature of the chamber with its high ceiling, ICE developed a large-format 4 way beam-steered loudspeaker that was successfully prototyped and built for the project by Acoustic Technologies Pty Ltd under the guidance of ICE Design
ICE Design also undertook the acoustic design of the small and difficult control room.
The design processes included a comprehensive market review of microphones (undertaken in conjunction with Radio New Zealand) and signal processing and transport using ICE measurement facilities and critical listening.
A major requirement of the system was provide clarity and separation of voices in the feeds to the Hansard recording systems. ICE Design’s extensive experience in this aspect ensured that the parliament’s requirements were met.
Australian Parliament House, Canberra
Since 1991, Acoustic Directions has designed and commissioned sound systems for the House of Representatives, Senate and Great Hall that deliver loud, extremely intelligible, natural sounding voices, with excellent immunity from feedback.
In addition to high-intelligibility speech, our system for the Great Hall was required to support vocal and light rock music performances that are often presented in this room. The loudspeakers were designed in conjuction with the Parliament’s architects, MGT Architects.
Each of our loudspeaker systems in Parliament house needed to overcome a challenging acoustic environment and accommodate strict architectural and physical constraints. Our solutions included the design of beam-steered line-array loudspeakers driven by complex signal processing.
We also developed a semi-automatic method to set up equalisation to minimise acoustic feedback for the large number of microphones in the House of Representatives and Senate. This method calculates the equalisation based on a series of acoustic measurements of the open and closed loop gains of the system. This method was published in an AES Journal paper.
The public galleries of the House of Representatives had a strong flutter echo between their side walls, and this had the potential to degrade intelligibility of the poliiticians’ speech when listeners in the gallery made a sound such as coughing. To rectify this, we specified an array of special acoustic diffusers for the walls, which diffused and directed sound into a 90 degree arc to retain the sound in the gallery. Conventional diffusers distribute sound into a 180 degree angle, and would direct the sound into the area where Members of Parliament sit.
NSW Legislative Assembly Sydney
The Legislative Assembly is the lower house of the New South Wales State Parliament. It is known as the “Bear Pit’, due to the rather “robust” debating style that often occurs in this chamber. The chamber was built in 1842 and is heritage listed, and while this listing ensures its preservation for future generations, it had profound implications for the new loudspeaker system.
Acoustic Directions designed a loudspeaker system that provides a very high speech intelligibility whilst overcoming constraints of sight lines, a high ceiling and diverse audience areas. Special loudspeakers were designed by Acoustic Directions in conjunction with the NSW Government Architects, which met with the approval of the NSW Heritage Office.
For the main loudspeakers covering the politicians, we developed an innovative cardioid-Bessel array that produced excellent coverage free of the interference effects that usually plague multi-driver loudspeaker systems.
Although Bessel arrays have long been used to create wide dispersion, we believe our use of two Bessel arrays in a cardioid format is a world-first.
The aural result was most pleasing. The performance and intelligibility was as predicted, with the sound being very natural and intimate.
City of Sydney Council Chambers, Sydney Town Hall
The heritage-listed Council Chambers is a highly reverberant room with a high ceiling. Using custom beam-steered cardioid loudspeakers, Acoustic Directions designed an innovative sound system which delivered high speech intelligibility to Councillors, with excellent immunity from feedback. The solution met the architectural requirements of architects Tzannes Associates.