Good Things Come In Threes
Hubei TV Wuhan Invests in New HDTV OB Fleet with Flexible Audio Networking
The 2008 Summer Olympic Games in Beijing triggered a nationwide surge in innovation which still persists on the Chinese broadcast landscape. OB1 is one of a fleet of three brand-new HD vehicles which entered service recently with Chinese regional broadcaster HBTV. CRESCENDO, AURATUS and NEXUS support this trio with state-of-the-art audio technology
Professional monitoring conditions and controlled room acoustics are essential for demanding HDTV productions with surround sound. While this is relatively easy to achieve in a fixed control room, OB vehicles present more of a challenge. On the other hand, when a broadcaster is converting all of its production facilities for surround sound, the OB vehicles are often converted first. This is true for Hubei TV (HBTV), a large regional broadcasting service based in Wuhan, capital of the Hubei province in Central China. HBTV approached the task with great attention to detail and now owns one of China’s first audio OB trucks featuring a fully ITU-compliant 5.1-enabled monitoring system!
Prominent in the Region
The broadcast landscape in China, the most populous country in the world, differs significantly from the scene in Europe and North America. Apart from CCTV, China’s central TV broadcasting service based in Beijing, there are also more than a hundred local stations in all major cities and conurbations all over the country. Hubei TV in Wuhan is one of the largest of them, with more than 2,000 employees in the technical production area alone. In total, HBTV runs nine free-to-air channels, three pay TV channels and one HDTV channel.
The broadcaster operates three large TV studios of between 400 and 800 square meter, all of which have digital audio consoles, as well as a number of smaller control rooms and media facilities with audio workstations. For larger audio productions HBTV also has a 300 square meter studio on the site featuring a DAW and a workstation controller. However, those fixed production facilities have not yet been converted to HDTV and surround sound. Hubei TV opted to implement these modern technologies on their technically ambitious OB trucks first.
Wuhan: A Metropolis: The Hubei province in Central China is a two-hour flight away from Beijing. About 8 million people — as many as there are in Greater London — live in the Wuhan area, Hubei’s capital, so it is a real metropolis. Wuhan lies on the Yangtze, the longest river in Asia. It is one of the major industrial towns in China, with heavy industries and several vehicle manufacturers. In 2007 — the year before the Summer Olympics in Beijing — Wuhan attracted international attention as the venue for the 5th FIFA Women’s World Cup.
HBTV’s new HD fleet includes two combined audio/video vehicles and the OB1, an audio-only truck designed around a large CRESCENDO console. From the outset, the truck was designed to be the best audio vehicle of its kind in China. It was completed in summer 2011. While the monitoring conditions are obviously limited by space constraints in the other two vehicles, for OB1 every effort was made to create a first-class, no-compromise monitoring environment in the considerably larger 5.1 capable control room. Chen Qinan, Vice General Manager of system integrator Guanhua, who were commissioned to construct the vehicle, not only designed the audio system for OB1 but also created a sophisticated acoustic environment in the monitoring compartment. It includes a complex wall structure as well as a number of custom-made diffusers. Also, the expanding section is constructed in such a way as to minimise the acoustically unfavourable, yet unavoidable, gaps and hollows. As a result, the OB1 is one of the first vehicles in China to fulfil the acoustic requirements for a 5.1 capable monitoring room as specified in ITU-R BS.775. This setup enables even the most ambitious productions to be realised in surround. This type of production is increasing in importance in China and especially for OB1. The vehicle is ideal for use in combination with the A/V vehicles of the fleet for covering sports events, live shows and major cultural events.
Moreover, as part of the redundancy strategy for major events, OB1 can also be used as a fallback unit for the sound department of other vehicles. Also, as mentioned earlier, since HBTV’s local TV studios are not yet ready for HD, the trucks will also be used as stationary control rooms for many local productions with the highest quality requirements.
Integral Failure Prevention
In addition to the main control room, the OB1 also includes a smaller multipurpose room equipped with a small digital console and a dedicated stereo monitoring system. The two racks, located on the left and the right of the console respectively, house not only the DAW and remote-controlled effects units but also a NEXUS STAR router, which serves as a network hub and hosts the CRESCENDO mixer cards. This made it easy to give the multipurpose room access to all the audio paths available on the NEXUS system thus turning it into a fallback control room. Since the two rooms can be separated from each other acoustically, by a sophisticated arrangement of doors, the smaller console can also be used for a different parallel project independently of the CRESCENDO in the main control room.
Planned Well in Advance
Lu Yong, senior sound engineer of HBTV’s TV department, first became aware of STAGETEC products when he visited a seminar organised by the Stagetec office in Beijing in 2005. While HBTV’s technical requirements at the time would not have justified immediate investments in large digital audio systems, Lu Yong was very impressed by the flexible networking capabilities of STAGETEC systems, for example at sports events where many distributed Base Devices are employed.
The era when you could cover a football match with just a single microphone was soon over in China. The Summer Olympics in Beijing in 2008, together with the introduction of HDTV, were the driving force and inspiration for major technology investments by many TV stations even if they were not directly involved in broadcasting this global sporting event. While TV sound had been typically mono until then, the upcoming HDTV technology required stereo and 5.1 audio. It soon became apparent that analogue systems would not be able to meet these new demands, if only in terms of the increased number of audio channels.
In 2010, plans for introducing HD technology at HBTV began to take shape. The broadcaster opted to construct three HD-enabled vehicles that would meet the highest requirements in terms of networking and redundancy. The audio department conducted extensive research into other TV producers experiences with major manufacturers products. Here, STAGETEC scored with the excellent routing and networking capabilities of the NEXUS system, meeting HBTV’s requirements particularly well.
Several Chinese TV stations have invested in modern, advanced HD vehicles in recent years. However, the various OB trucks in a fleet have often been designed and constructed independently of each other at different times. This regularly led to the use of different technical systems — for example, audio routers and mixing consoles from different vendors. In planning their new HD fleet HBTV followed a completely different approach, impacting very positively on the connectivity, flexibility, and compatibility of the audio systems on the three trucks. Both the CRESCENDO and AURATUS consoles installed and the NEXUS audio networks are fully compatible and can be combined in various configurations — either as part of redundancy setups on major live productions or configurations with totally free routing of all signal sources across all the vehicles. This results in many tangible benefits. For example, two mobile Base Devices are part of the fleet and can be used on any of the OB vehicles as required. The HBTV project was the perfect scenario to fully exploit all the advantages of networked and integrated audio systems.
Mutual Fallback Systems
One key criterion was a consistent failure-prevention strategy for all three vehicles. A flexible audio network proved to be the perfect answer to meeting the redundancy requirement. In the case of a failure of one truck, another one could easily take over on the network. Senior sound engineer Lu Yong says: »The audio network provided by the NEXUS is extremely open and flexible so that all audio signals are available at each location wherever they are needed on the system. With the previous technology this would have been almost impossible to achieve.«
The HBTV decision makers were impressed not only by the networking features and the highly flexible synchronisation options but also by the extremely high quality of the NEXUS microphone inputs, the signal-processing functions and the entire signal path. This was verified carefully by the executive system integrators using professional measuring instruments during a later phase of construction.
Growing with the Business
In addition to the OB1 audio truck with its large CRESCENDO control room, HBTV now also has the OB2 with 16 cameras and a CRESCENDO and OB3 with eight cameras and an AURATUS on board.
Each of the three vehicles includes an expanding side section to increase the interior space and the audio mixers are installed in line with the direction of travel. The OB1 and OB2 trucks were designed and constructed by Guanhua system providers from Beijing while Jolly Sound from Wuhan were commissioned to build OB3. In terms of technical design and practical implementation all three OB trucks are of excellent quality. Many elegant space-saving solutions were found, for example, a fl ip-up producer desk under which two NEXUS Base Devices can be hidden. The CRESCENDO in OB1 features 40 faders, although the console frame provides space for two additional fader modules, allowing for future expansion up to 56. Similarly, the CRESCENDO in OB2, which was equipped with 24 faders initially, can also be expanded with two additional fader modules.
Mobile Units for All
The sound control room in OB3 is home to an AURATUS console configured with the maximum of 24 faders. At fi rst, the engineers at Wuhan slightly underestimated the capabilities of this very compact console. Lu Yong says: »Initially, we used the AURATUS only for simple routing jobs with no signal processing. However, it soon became obvious that the integrated signal processing meets the highest demands, so that even complex problems can be overcome.«
All three OB trucks are equipped with Dolby E® encoding integrated into the NEXUS. The Dolby DP570D multichannel-audio tool is provided for reference monitoring. The NEXUS also distributes signals from the vehicles’ intercom systems, which include both wired and wireless components.
The three vehicles of the HBTV fl eet share two mobile NEXUS Base Devices. These are connected over redundant 200 meter long fi bre-optic camera cables. The Base Devices are used, for example, as stage boxes at large events. Each Base Device has 24 MIC/line combo inputs, 16 line outputs and four AES3 digital I/Os. For smaller operations in the vicinity of the vehicles, or direct audio connections between two vehicles, more analogue and digital audio channels are available via local patch bays and multicore cabling.
Raising the Tone
Hubei TV’s new HD vehicles are the result of meticulous planning which betrays great attention to detail. And with all its numerous nuances, the big picture shows an exemplary degree of flexibility and resiliency. Not least because of their great scalability and interconnectivity capabilities, STAGETEC systems became part of a landmark on the broadcast landscape, namely one of the fi rst mobile surround control rooms in China.
And the story doesn’t end here. At the beginning of the year, Hubei TV placed another order which will convert the broadcaster’s three large studios including their control rooms, to the latest HD technology. Two more CRESCENDOs and an AURATUS will serve there in future, supporting crystal clear surround sound throughout the Hubei region.