Inside TV Centre Where Wireless Intercom, AoIP And MADI Coexist

The opening of the rebuilt and refurbished Television Centre in west London was one of the most anticipated broadcast installation events of 2017. Five years on from being closed after the site was sold by the BBC, a smaller studios complex is now in operation. The facility is equipped with a 4k IP video infrastructure, while the audio side features Studer mixing consoles and the first installation of the new Riedel DECT-based wireless intercom running on an AES67 network.

TV Centre or TVC, as it has been known to professionals and viewers alike, first opened in 1960 and quickly became the symbol of BBC Television. The modern, brutalist concrete building housed production and management offices, network presentation galleries and eight studios used for producing a variety of programmes, from light entertainment and situation comedies to news and current affairs.

Over the years a series of technical upgrades was carried out at TVC that saw the facilities move to colour transmission, followed by stereo sound and, more recently, high definition and 5.1 surround sound. While this continued to bring in work, for shows made by commercial broadcasters and independent production companies as well as the BBC itself, the future of TVC came into question during the 1990s.

The site was eventually sold for development in 2012 and ceased operations the following year, with the provision that any new premises would include production studios. During the redevelopment period many of the BBC’s top-rated programmes were moved to other studio centres, including Elstree Studios, both the Corporation’s own facilities there and those of the commercial film studio, and Maidstone Studios for live music show Later… with Jools Holland. News, sport, current affairs and children’s programming had already moved to MediaCityUK in Salford in 2011.

The new TVC studios became operational at the beginning of September 2017, while building was being completed on the surrounding parts of the redeveloped premises. From the road the familiar rounded lines, concrete and brick of architect Graham Dawbarn’s design remain. Behind the facade there is now a branch of media club Soho House plus hotel rooms, apartments, bars, restaurants and a gymnasium.

There are also three television studios, plus video editing suites, run by BBC Studioworks, a commercial subsidiary of the broadcaster that operates its facilities operations and business. Five of the original eight studios, with their technical areas, have been demolished, leaving TC (Television Centre) 1, TC2 and TC3. The galleries of TC2 and TC3 have been reoriented by 90 degrees, so that they face the same direction as that of TC1.

A major consideration was that TV production will now be carried out alongside a hotel and private flats. While these are not very close to the studios, there was still pressure to be neighbourly and ensure that sound was contained. The original sound treatments and proofing are being used, although door seals have been replaced. There are also "two levels of acoustic spaces" within TVC to further minimise noise.

David Conway, MD of BBC Studioworks

David Conway, MD of BBC Studioworks

Despite the additions to the site and some remodeling of the studios complex, including a new, relocated reception area, anyone familiar with the old TVC will not feel entirely out of place. Many of the linking corridors and common spaces appear the same as before, even down to the 1960s-style lettering on the signs outside the studios, some of which are original although others are repros.

"It's a mixed use development," comments David Conway, managing director of BBC Studioworks. "But there is the history of the old building on the first two floors of the doughnut [the circular central structure]. TV is on site again and although we've invested a lot in technology, there is also the heritage."

Part of the technical investment has gone on the vision side, with Sony 4k cameras now available in the three studios. Conway says there won't necessarily be an immediate benefit for viewers by offering Ultra HD facilities but it does provide "future-proofing" while the market is in a state of transition.

Less obvious but not less significant is the emphasis on audio, particularly on the communications and networking side as well as mixing. TVC has the distinction of being the first installation of Riedel Communications' new Bolero DECT-based intercom system, although other implementations happened soon afterwards. Sound supervisor Andy Tapley says BBC Studioworks had been looking at ways of extending roaming capabilities for production staff at it facilities, a process that had involved other intercom brands.

"Going back probably ten to 12 years ago we were using Clear-Com FreeSpeak," he explains. "The idea was to have a DECT-based system on different aerials with connectivity throughout TVC. That worked to a large extent, back in the days when TVC was eight studios and we included outside areas like the Blue Peter Garden."

In 2009 Clear-Com introduced FreeSpeak II, which Tapley says was a "massive improvement" in terms of DECT performance and general quality. By this stage, Studioworks was using Riedel Artist at Elstree Studios, which it found fitted the growing trend in production for set-ups to develop, with intercom configurations changing "on the fly".

TC2 production gallery. Click to enlarge.

TC2 production gallery. Click to enlarge.

This, says Tapley, was a major move on from how productions had worked in the past: "Originally in TV productions you'd have set positions, such as a director and a producer sitting at a table and another producer somewhere else. You'd tell them that they had to sit there because that's how it worked with the comms panels. But that's not how it happens now. They want to come into a space and say how they want to use it. So it was very important for us as the facility provider that we could give that to our customers."

While Riedel did have a wireless option on the market, the Acrobat system, Tapley and his colleagues considered FreeSpeak II was better. "The obvious answer at the time was to go into a hybrid system of FreeSpeak II and Riedel," he says. Approximately two years ago Tapley approached Riedel and its newly appointed director of product management, Jake Dodson, when, unbeknownst to him, the company had started development of what became Bolero. "I said it would be great if we could have a joined up wireless system that integrated with the Artist mainframe and gave us all the benefits of an Artist system," comments Tapley.

Dodson revealed that he was working on something that would offer what Tapley was looking for. After signing an NDA, BBC Studioworks collaborated with Riedel on developing the new system, leading up to tests at both TVC and during rehearsals of top-rated BBC show Strictly Come Dancing at Elstree. Dodson says the TVC trial involved the first prototype hardware of the system, comprising two belt packs and one antenna. "TVC is on three different levels and has long winding corridors with cable trays on the ceilings," he comments. "And everything was a building site, so in other words it was a RF nightmare. We did the first test from the meeting room and walked along corridors and got about 200 metres of coverage."

In a bid to make things harder, the test was moved down to the then under-construction TC1. Because this was a hard hat area at the time, a member of Tapley's team took the antenna in to place it. "We walked out of the room and after about five metres we ran into some problems," Dodson says. "We were a bit surprised and I thought, 'It's going to be one of those days.' Then another metre further and everything was perfect. It later turned out that the antenna had been put into the equipment room, which has big thick metal doors, explaining why there were dropouts."

R&D on Bolero was completed in time for it to be installed into TVC ready for its official opening on 1 September. Tapley says BBC Studioworks was the first facility to have the system, which has been "taken to the max". This involves the maximum number of 100 belt packs, split across the three studios: 40 in TC1, 40 in TC3 and 20 in TC2. These run on an AES67 network operating under DECT, which provides full roaming capability.

TC1 in action for The Jonathan Ross Show, the first production to use the 'new' TVC. Click to enlarge.

TC1 in action for The Jonathan Ross Show, the first production to use the 'new' TVC. Click to enlarge.

TC1 has its own Artist frame and the one in TC3 is configured identically. TC2, which is a smaller studio, shares its frame with the central apparatus room (CAR), covering common facilities and four-wire connections. "Each one of those frames has AES67 cards fitted," Tapley comments. "There are five AES67 cards fitted in each of the TC1 and TC3 frames, with three in TC2's frame. That means in TC1 we get 40 ports, 40 AES67 channels, which go on the AES67 network and then connect through that to Bolero belt packs."

This is achieved by having each AES67 card connecting to an AES67 switch; all these are in turn are connected to the Bolero aerials. Tapley explains that the networking system is effectively two parts: one side centres on Artist, from where all configuration of panels can be carried out; the other features AES67, with the ability to connect to the switch using a browser, from where the set-up can also be configured. "Each Bolero belt pack is effectively a portable panel," says Tapley. "It's got six full duplex channels on each and can also be used for all the other Riedel functions, such as triggering GPOs [general purpose outputs] or remote audios."

Sound supervisor Andy Tapley

Sound supervisor Andy Tapley

Each antenna in the TVC installation is able to connect to ten belt packs, with the entire site covered by 22 antennas. TC1 and TC3 have seven antenna in each and TC2 has four, with the remainder in more public areas, including reception, the assembly point and the basement. "As well as the fixed panels we have in the control rooms we have a number of portable panels that we can patch into any location," Tapley comments. "The system is AES over CAT5 and we have CAT5 points dotted all over the studio. We can just put a panel where we need it and program it up very quickly."

Wireless also plays a major role on the programme audio side, with most TV productions now reliant on radio microphones and in-ear monitoring (IEM). "It's a standard part of the sound rig," acknowledges Tapley. "It's not whether you'll be using wireless mics, it's how many channels of them you want. They are an essential part of pretty much every TV show and with that in mind I designed a system that enabled clients and the crew to have a central point to rig the radio mic rack, which meant having aerials installed already."

The RF antenna system for TVC was installed in conjunction with hire and installation company Terry Tew Sound and Light, which also supplies wireless mic equipment (most usually Sennheiser but also other brands, including Shure) and deals with spectrum allocation for the site. Because of its size TC1 has four antennas, which are variable gain Betso units linked to a Sennheiser ACA-2 four-pair antenna combiner in the studio's tech store, This area also features a pair of RF tie-lines to the CAR and a further pair to TC2, enabling the two studios to be linked for very big productions.

TC2 contains two passive Sennheiser A2003 antennas linked to its tech store, which in turn has a further two RF tie-lines to the CAR. TC3 features a similar set-up. Because many productions these days are not content to stay within the confines of a studio, RF capability has been made available in other parts of TVC, including main reception, the old red tea bar and various corridors. These have antennas, either Betso or Sennheiser, or RF tie-lines that are cabled back to the CAR. Individual pairs of antennas can be sent to any studio via the CAR, which connects to tech store tie-lines; alternatively up to four pairs of antennas can be combined using a Sennheiser ACA-2 in the CAR, from where signals go to the tech store of the relevant studio.

"Every studio has aerials installed, with feeders going back to the tech store," Tapley comments. "It means we can patch a fibre stage box in there right by the radio rack receiver, plug a couple of coaxs in for the aerial feeds and connect the receiver outputs. Further to that we put in tie-lines to other areas of the building. This means you're not having to rig duplicate radio receiver mic racks if you have an outside-studio activity. Effectively you can have a presenter walk out of TC1, go down the corridor, into reception, through the assembly area and even go outside, all on the same radio receiver racks. So it's a proper network with RF combiners."

Sound gallery of TC3, showing Studer Vista X console and Glacier grams desk. Click to enlarge.

Sound gallery of TC3, showing Studer Vista X console and Glacier grams desk. Click to enlarge.

Each studio has its own audio control room, all of which feature Studer mixing consoles. BBC Studioworks has been using the brand for some time, starting with the Vista 5 for main production mixes with an OnAir 3000 as the 'grams' desk, playing in music and effects from PC-based SpotOn software.

Within the last four years Studioworks began to use the Vista X, launched in 2014, installing one in the gallery of the George Lucas stage at Elstree Studios for Strictly Come Dancing and other big light entertainment (LE) productions. TC1 and TC1 feature brand new Vista X desks, while TC2 has a Vista 5 that was previously installed at a studio in Bristol for the game show Deal or No Deal. All three sound galleries have Glacier mixing surfaces in the grams role.

"The Glacier is a new product for us," says Tapley. "Effectively it has replaced the OnAir and is doing the same job. It has the same back-end as that mixer but a new control surface. They are quite movable, portable panels and get power over Ethernet. One CAT5 connects into the panel, which means you're not so fixed and rigid in the way your desk area is set up because operators might want to move a panel to the other side."

The Vista X and the Glacier frame are connected over fibre plus Studer's proprietary A-link technology. On top of this is a series of MADI (multichannel audio digital interface) highways that run between all three Vista consoles and the studios' respective hybrid routers. TC1 has three MADI paths from its router to the Vista X. A further MADI link runs into a DirectOut ANDIAMO 2.XT (AD/DA MADI converter box, which handles bay inputs and outputs for AES and analogue feeds, plus an additional MADI connection to the Glacier. This means the grams desk could take over the programme mix if there was a serious problem with the Vista.

Tapley says an audio over IP (AoIP) network was considered for the production audio installation but the question would have been what was the best way to connect that to the Imagine router. "We found that MADI was the best option for us," he adds. "It's totally interoperable and we needed a point-to-point solution. We wouldn't have been getting any benefits from using an AES67/AoIP solution for that."

AoIP does feature as part of a multitrack recording and mixing set-up. A Merging Technologies Pyramix system runs under the RAVENNA AoIP protocol, which is fully compliant with the AES67 interoperability standard. "We convert two MADI streams into a Horis I/O box, which creates a RAVENNA network that connects to the Pyramix PC," Tapley explains. "It's a system we've been using at Elstree on both the George Lucas stage and in Studio D very successfully. We use it on Strictly Come Dancing for multitrack recording of the band and remixing, as well as post-production." All TVC audio rooms are capable of 5.1 mixing, with monitoring on ATC 100s.

The new TVC went into operation the day before its official launch, with a recording of ITV's The Jonathan Ross Show. This has been followed by a variety of productions for other commercial broadcasters as well as the BBC. But whatever channel the production ends up on, it's just good to have the place back and working again.

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