Japanese broadcaster Asahi Television Broadcasting Corporation (ABC) has upgraded its 202 OB truck to a 5.1.4 immersive environment with a combination of Genelec three-way coaxial monitors and GLM calibration software.

‘Organisations like the Association of Radio Industries and Businesses are discussing standards for next-generation broadcasting, and three-dimensional audio is under consideration,’ says Sadanari Iwahashi of ABC’s Production Engineering department. ‘When we thought about a broadcasting van that could be used 15 years in the future, we concluded that it’s necessary to support immersive sound.’

The move is a coordinated initiative across the ABC group. In addition to the remote truck, its MA (Multi Audio) room has also been upgraded to a 5.1.4 immersive format.

‘When broadcasting starts to support immersive, we’ll be able to monitor the sound live from the site, and recordings can be brought into the immersive MA room for further processing,’ Iwahashi says. ‘It makes sense to have an OB unit ready to record immersive sound for many reasons. For example, when we record a concert, we can approve the use of the sound in other events and programs as well. It’s also important that we have four monitors installed in the ceiling from the start, so we can just begin immersive monitoring without the hassle of setting up.’

Nihon Onkyo Engineering planned the acoustics, while Keisei Motors, a company with extensive experience in OB vans, manufactured the vehicle. The LCR channels are handled by three 8341 coaxial studio monitors, and thanks to a custom-designed 2.2 m high production room, ABC was able to mount four 8331 height monitors in recesses in the ceiling. As the smallest model in The Ones series, the 8331 is suited to small rooms where space is limited, and this unusually high ceiling meant that they could be placed at the same distance from the listening position as the LCR monitors in the front. Low frequency duties are handled by a 7360 subwoofer.

‘The goal was to ensure as much distance between the monitors as possible,’ Iwahashi says. ‘One particular challenge was the position of the left and right rear 8331 monitors, which due to the structure, would be closer than the L, C and R monitors. The ideal angle for rear channel monitors is 110° (±10°) but, if we positioned these and the LCR channels equidistant to the listener using that angle, they would exceed the width of the van. So we compared the sound prioritising the angle and then the distance many times, and in the end we decided to prioritise the angle. In order to maximize the distance, the rear monitors were also installed slightly above the horizontal position, at an elevated angle.’

As Smart Active Monitors like The Ones integrate closely with GLM software, ABC was able to compensate each monitor for frequency response, playback level and distance delay. According to Iwahashi, GLM created the perfect environment for accurate immersive monitoring – despite the acoustic demands of the space.

‘We adjusted the angle of each monitor, fixed the reflections with sound absorption, calibrated them and then repeated the listening and fine-tuning process,’ he explains. ‘GLM software was a great help in building an ideal monitoring environment. The visualisations of frequency dip points were easy to understand too.

‘We tested several different studio monitors during the installation process,’ Iwahashi continues. ‘The Ones stood out because they reproduced sounds from all kinds of sources clearly, right across the frequency spectrum. Additionally, in an OB unit, a TV monitor must be set up in front of the mixer – and the monitors must be positioned in a way that doesn’t block it. This is easily achieved with the point source design of The Ones, since they can be orientated in either the vertical or horizontal position without any compromise in performance.’

With Dolby Atmos now a household term and 3D soundbars commonplace in millions of homes, Iwahashi is confident that ABC was right to step up to immersive when it did. ‘These developments support my initial feeling that an immersive system is an important and necessary feature for any OB van, and I’d like to continue to work harder in this format in the future as ABC creates more appealing programmes in immersive.’

More: www.genelec.com