Installed Audio: designing 3D experiences

While audio has been a staple component of exhibitions, cinemas, concert halls, places of worship and theatres for many years, there has been a rise of interest in applying ’3D’ or Virtual and Augmented reality (VR and AR) technology to these installations.

Germany’s Klang technologies are purveyors of 3D in-ear immersive mixing solutions and their KOS operating system has just been upgraded to version 3, adding workflow and other improvements. The New Life United Pentecostal Church, based in Austin, USA, has recently installed two KLANG:fabrik 3D IEM monitoring systems and two KLANG:quelle headphone amplifiers. The KLANG:fabrik units are fed signals via MADI from the church’s DiGiCo SD9 mixing console – one KLANG:fabrik provides eight stereo mixes for use by the musicians on stage during worship services, who then use the two KLANG:quelle headphone amplifiers, connected over a single Dante-networked cable, to create their own individual mixes for each performance.

The second KLANG:fabrik unit is dedicated to the lead vocal and six backup vocalists, through two separate stereo mixes, leaving more than six additional mixes for other applications, such as guest performers. “I barely have to touch monitors anymore,” says Terry Golden, FOH engineer at the church. “The musicians can create exactly the mixes they want on their own using the KLANG:app, which is phenomenal. The KLANG:fabrik we installed at New Life Austin can be summed up in two words, “Its simple!”

Borås, located just east of Göteborg in Sweden, is often compared to Manchester – mainly because of its exceptional rainfall statistics. Sunnier climes are apparent in the town’s Stadsteater, where Klang’s in-ear solutions are making the life of the theatre’s head of sound, Tobias Walka, much easier. “Our mixing system was already fitted with Dante, so we used that to connect to our KLANG:fabrik unit,” says Walka. “The KLANG:app is very intuitive and easy to navigate, especially when used on a larger iPad, Apple Mac or Windows computer. We hooked it up, patched it, assigned channels to users, added names and so on and it all worked on the first try.”

The outputs from the KLANG system are connected to six Sennheiser EW300 wireless in-ear monitors (IEMs) and the system was premiered at the theatre’s production of the musical Cabaret, with the 4-piece band and the two lead actors using IEMs. “Most of the band members were familiar with working with IEMs, but all were extremely impressed with both the sound quality and the ease of use of the KLANG system,” says Walka.

“They all loved being able to adjust their levels on the fly during the gig. Since the band was seated during the whole show they loved the 3D aspect of the system as they could each place the sound of the other instruments where the person playing the instrument was physically situated. They all felt that it also helped greatly with both separation and clarity.” The band commented that this was the first time that in-ears has truly worked for them. “In the past they felt IEM was a necessary evil, but with KLANG 3D IEM they loved it,” he adds.

Astro Spatial Audio in the Netherlands has installed their immersive object-based audio system at Germany’s Folkwang University of the Arts. The installation features the company’s SARA II Premium Rendering Engine at its heart and Bjorn Van Munster, founder and director of Astro Spatial Audio, says that “The SARA II Premium Rendering Engine represents the world’s most advanced implementation of object-based immersive audio plus powerful tools for the optimisation of room acoustics.”

Van Munster says that the system is “entirely brand agnostic” offering sound designers and engineers an entirely new 3D audio toolkit that can be quickly and easily scaled from one venue to the next. The Linux-based SARA II is a 3U rack-mounted device, offering up to 128 MADI or 128 Dante configurable network pathways at 48kHz/24bit resolution. All paths are assignable to at least 32 audio input channels that can be rendered to up to 128 independently processed sound source outputs.

Astro say that even with full CPU processing, latency is guaranteed to be below 5ms. A browser allows access to an intuitive GUI, and simultaneous control from multiple devices, ranging from mixing consoles and DAWs to tablets and phones running either Android or iOS. SARA II features a 2.8” TFT LCD colour touchscreen with a number of different control options. “To ensure reliability, each SARA II engine hosts several on-board redundancy options, while systems can be linked as required to form massive immersive experiences across vast spaces,” says Munster. “Use of the Open Sound Control (OSC) protocol delivers interoperability with third party systems.”

Steven Boardman, part of London-based Jungle Studios’ tech team, a company who specialise in research and development for immersive sound, believes that his choice of equipment and software for installed immersive audio depends on many factors. “You need to account for the budget, acoustics, size of the space, the amount of speakers needed,” says Boardman. “Each has to be taken into account, along with the time it takes to implement.”

Boardman’s personal choice for small-to-medium, full periphonic and horizontal permanent installs, would be point source speakers like Genelec’s The Ones. ”They are better at reconstructing a spatial scene, as all the frequencies are spatially aligned,” he says. “The Ones also have SAM (Smart Active Monitoring) so they can be calibrated for flat frequency response which makes the rendering more accurate. For large temporary installs, I would use L-Acoustics or d&b Audiotechnik. They both provide high output coaxial drivers that sound really good.”

Amadeus are a French-based company, specialising in high-end sound reinforcement systems and custom studio speakers. They have been involved in a staged dramatisation of the 1938 ‘Xi’an Incident’—an event which is credited to have created modern China.

Amadeus worked with its distributor, Chinese-based Guangzhou Sign King ET Co., Ltd., Swiss-based company Sonic Emotion, and British manufacturer of digital mixing consoles, DiGiCo, to design and install the sound setup, alongside creative input from the Paris-based Théâtre National de Chaillot. Wymen Wong, marketing manager of Guangzhou Sign King says that, “The Amadeus team combined all the technologies that were used based around their speakers. It was a very complex and comprehensive list of gear.”

Amadeus’ team set the system up in the theatre, tuned the speakers and trained the Chinese staff. “I believe since my beginnings working in live theater, that inside each sound technician is an electro-acoustic ‘creator’ able to sublimate, reinterpret or magnify a musical project,” says Marc Piera, Chaillot National Theatre’s sound department manager.

“These new techniques of diffusion finally offer us the choice, of building our space, with its depths, its images and its relationship with the scenic elements of the stage. These new sonic techniques allow us to be architects of the sound, sound creators, finally freed from the dictates imposed by the ‘acceptable’ or usual physical positions of the loudspeakers in a theatre.” Wong says that the installation itself uses the DAW Reaper with IRCAM’s ToscA plug in. The setup also includes Amadeus’ Wave II sound processor to reproduce sound sources that appear virtually outside the room using Wave Field Synthesis (WFS) technology.

Apparently based on Huygens’ Principle of 1678, Gaetan Byk, Amadeus’ marketing manager says that the idea of WFS was developed in the Netherlands in the 1980s by the Delft University of Technology. “The WFS concept makes it possible to synthesise ‘sound holograms’ by simulating acoustic waves produced by virtual sound sources,” he says.

“They are each controlled with a delay and a gain to form a wave that emanates from the desired location of the virtual source. This process is repeated for each sound source in the sound scene.“ Byk says that the major benefit of the WFS technique is to create a coherent sound field in an extensive area, therefore preserving the fidelity of the spatial image – the position of the sources—even for listeners located at the periphery of the zone or for those moving within the zone. “Wave field synthesis thus provides the listener with consistent spatial localisation cues over an extended listening area,” he adds.

Dutch-based Alcons Audio is one of Europe’s leading developers and manufacturers of professional sound systems that are used in theatres around the world. Their latest Pro Ribbon immersive audio system was recently demonstrated at Integrated Systems Europe (ISE) 2018 and was comprised of a hybrid 9 by 8 immersive surround configuration, featuring an array of Alcons Audio pro-ribbon loudspeakers, driven by 26 channels of Sentinel amplified loudspeaker controllers with “lossless” AES3 digital signal distribution.

Alcons Audio demonstrated the system with native and up-mixed Dolby Atmos, Auro-3D and DTS:X content, as well as Astro 3D Spatial Audio material. Alcons’ Pro-ribbon speakers, as their name suggests, are based on ribbon drivers that were devised by the company’s Philip de Haan, the senior research and development engineer. “Since 1983 we’ve been expanding the learning curve and did a lot of research on new materials, techniques and production processes. We’ve tested every medium-to-large sized ribbon driver on the market, to see and measure for ourselves what the current status of ribbon development is,” says de Haan.

”Now this know-how has led to a new generation of ribbon drivers, with the RBN601 being the first result of that.” Alcons says that the advantage of ribbon drivers is that distortion is low and there is no compression threshold, which helps maintain tonal balance at all sound pressure levels. The aforementioned RBN601 has a peak handling power of 3000W and is, Alcons claims, currently the most powerful ribbon driver on the market. The RBN401 is a scaled-down version of the RBN601, with a power handling of 50W/800W and an efficiency of 100dB. Alcons call it the “baby Hulk”— the smaller brother of the 601 ‘Hulk’. One of the beneficiaries of the Pro Ribbon technology is Sweden’s Royal Dramatic Theatre, or Dramaten.

In 2015 the theatre installed an Alcons Audio-based system in its main space. “The challenge was to find a physically small system without compromising in sound,” says Dramaten’s technical project manager Johan Bengtsson. “We demand even coverage throughout all four levels of seating and a good stereo image. The available positioning for the system was very limited because the building is historically protected and we have to consider sight lines.” Electrosound AB, a member of the Alcons Global Ribbon Network, installed the system, comprising the L7 speakers—with Pro Ribbon drivers— and LR7B bass units.

There are now quite a range of technologies being utilised in providing immersive audio solutions for installed systems. A mixture of software and cutting edge hardware technology is being combined to offer a true immersive experiences to audiences, while at the same time making the technology easily useable by the performers and artists. With competition for consumer’s attention being drawn to the increasing sophistication of in-home entertainment, these new technologies could make the experience of ‘going out’ a much more memorable experience in future.