The latest issue of our company magazine called »Stages« was released on the occasion of the AES Convention. Read the most interesting articles online:
- CANTUS/NEXUS Installation at the Mitteldeutscher Rundfunk Broadcasting Service
- The Ü2000 O.B. Van of the Mobile Production Center MPC (TV Productions)
- »Past the Future« – Thoughts by B. Morgan Martin
- NEXUS in the Vatican
- Experiences with the Stage Tecs 28-Bit Converters, by Jakob Händel
- NEXUS STAR Installation at the SWR Broadcasting Service
- Berlin Concert Hall
Stage Tec's CANTUS and NEXUS systems are playing key roles in MDR's brand new TV centre.
The German broadcaster's Leipzig facility, with its futuristic architecture and state-of-the-art broadcasting equipment, opened for business in June last year. Three 96-channel CANTUS consoles are in operation in the production studios, while a giant NEXUS network powers the main switching room, together with links to the studios, control rooms, and on-air sound processors. The network consists of 21 base devices with a total of 1,800 x 1,700 connections.
Yet, no matter how sophisticated the audio equipment may be, video remains the most important aspect of a TV station. Consequently, the MDR's big NEXUS system abides by the »audio follows video« rule and is happy to work – efficiently – in the background.
Cramming a complete TV control room, with all the necessary video and audio systems, not to mention reporters, into an OB van, has always been a challenge. Now, at last, thanks to new technological achievements, making a confined space more workable, has become a reality with the Ü2000.
Big is Beautiful
The Ü2000 is more like a studio complex than an OB van. It features 13 work stations, 22 cameras, 10 digital video tape recorders, video harddisk recorders, slow motion, graphics and effects, two separate video control rooms (all-digital), two separate audio control rooms with multichannel sound capability, a CANTUS with slave console, and a NEXUS network. Thanks to their compact size, small weight, and flexibility, CANTUS and NEXUS have all but become the standard for OB vans. But in every other respect this van, built by Mefisto Sonderbau in Reutlingen (Germany) for the Mobile TV Production Centre, is far from standard.
A Swinging Sandwich
Like many big OB vans, the Ü2000 is based on telescopic, extendable parts: for the journey to the location the truck is driven in its retracted mode and stays within the maximum permissible vehicle dimensions. On location, however, the van demonstrates its first extraordinary feature when it is extended both sideways and lengthways. A new sandwich principle applied to the walls of the van allows them to weigh less and provides greater stability compared to traditional OB van constructions. This allows the telescopic sections to be longer. Thanks to this technology, the Ü2000's sides can protrude by 1.35 m, giving the crew greater space and comfort to work in.
Fit for Switzerland
The Ü2000's design had to meet yet another requirement: its total weight was not to exceed 34 tons. In Germany, 40 tons are no problem, however in neighbouring Switzerland, such heavy trucks are not allowed on the roads. But here, too, the sandwich principle helped to optimize the van's weight. In addition to that, the weight was reduced wherever possible, with the result that the van is now allowed to enter Switzerland. Simply remarkable, since vans of this size would not normally be granted entry. The Ü2000 is accompanied by an ancillary van which houses the second set of sound and video control rooms, thereby allowing for the airing of two completely independent versions of international sporting events, etc.
Making Light of It
The audio gear is lightweight too. Besides their superior specs, the CANTUS and NEXUS provide additional advantages: the compact and lightweight construction of the NEXUS base devices, the CANTUS racks, and the console make them well suited for mobile applications. All components excel by their low power consumption and heat emission. As a result, the cooling system of the audio gear can be kept to an absolute minimum, thus saving additional weight and space. Thanks to the installation of one base device in the front part of the van, and a second one in the rear, internal crosswiring can be kept to a minimum: just one optical link. Three additional portable base devices can be set up on the premises using lightweight optical cable rather than heavy multicore. If necessary, the sound control room in the ancillary van can be linked to the OB van. The ancillary van is fitted with a CANTUS slave console that could also be installed externally and used as mobile unit.
Size Test Passed
Stage Tec's seminar at the Banz monastery in February was a good opportunity for the Ü2000 to demonstrate its flexibility, even though the video projection tasks and audio link with the conference hall didn't even so much as scratch the surface of its possibilities. The real challenge at Banz was inching the Ü2000 through the monastery's entrance. Another few centimetres and it would have been parked up outside.
The Author: B. Morgan Martin has been chef engineer of MetroTape in Los Angeles as well as consultant of other US film and tv production houses. Today, he and his partner Arnie Toshner are representing Stage Tec in the USA.
In '85 the first large digital console appeared – with high cost and major limitations. Since then, various other digital consoles have been either too costly or too unreliable to be truly successful in the US broadcast world. But in 2001, the year we are supposed to reach Jupiter along with HAL 9000 (1), it can be argued that Digital's the way to go!
There Comes a Time to go Digital
A bit of history: in about 1980, I was Chief Engineer of MetroTape, a fairly large TV Production and Post facility in LA.
At that time, my staff and I were faced with the task of specifying new audio consoles that we hoped would meet our needs for many years to come. Our counterparts around town were dealing with the same challenge. Some of the consoles we all speced then remained in use for as many as 20 years! But despite our careful attempts to provide for future needs, we soon found that we were »running out of faders«. We often had to wheel in »side car« consoles to have enough inputs for increasingly more complex productions. For example, »Name That Tune« suddenly went from one live orchestra to an orchestra and a band, instantly doubling the number of inputs we needed. Who would have thought!
We also found that from time to time we could have used more than the 10 aux busses we had built into our consoles at MetroTape. We could have expanded those consoles, by adding more input strips – but at prohibitive cost. Adding more auxes, subs, and the like was impossible. And we weren't alone – others around town were running into similar difficulties.
CANTUS to the Rescue!
Today, with Stage Tec's CANTUS digital console, the situation is radically changed. With CANTUS it's easy to change the console's »spec« as your needs change. You just define a new CANTUS »project« with however many inputs, auxes and subs you need. It makes keeping up with changing needs easy!
Of course, the maximum number of input channels a particular CANTUS can have will depend on the number of plugin ADSP cards you install. These ADSP cards, housed in one 3U high Rack, handle all of the processing for a CANTUS console. And unlike with analog consoles, if someday you find you need more channels than there are cards for, it's a simple matter to plug in more ADSP and an update program and voila, you'll have more input channels!
Adding Faders is easy!
Even adding more faders to the console can be a snap! Example: the CANTUS console recently installed at a broadcast network's stage in LA was built with blank panels for future expansion. If the folks there decide that they want more faders, installing them will be as simple as plugging in the fader and knob panels, an interface card, and linking cables. A quick software update from a floppy disk and they would be in business.
One I/0 Section for All
With analog consoles, it's nearly impossible to add more microphone inputs, mainly because a console's mic input circuits are usually a part of its channel strips: new microphone inputs require new channel strips – which means very expensive modifications to the surface.
With CANTUS, adding more inputs or outputs is simple. All inputs and outputs to a CANTUS console come from a NEXUS digital audio router. If you need more microphone inputs, or more analog outputs, or maybe I/O for a new digital format that didn't even exist when you bought the CANTUS, it's only a matter of expanding the NEXUS, usually just by plugging in cards.
And since the NEXUS is not necessarily tied to just one CANTUS console, any CANTUS in your plant can use any input and output in the NEXUS, making it easy to say connect microphones in stage 2 to the CANTUS in stage 1.
No Routine Maintenance!
Another issue with analog consoles is the matter of intermittent switches and noisy pots. Those that are not used often are particularly susceptible to embarrassing failures. It's a sad thing to see a highly paid, talented tech spending the morning twisting knobs and pushing buttons to insure that when they are used »on air«, they work without problems.
As time goes by, CANTUS users find that there is basically no routine maintenance needed for their CANTUS consoles. There's no need to exercise pots and switches to make sure they don't go noisy or scratchy because there's no audio going through any of the controls on the surface.
CANTUS knobs and switches are merely controllers, with the actual fading, muting, etc., done by the processors on the ADSP cards. And real world experience has shown that the CANTUS/ NEXUS hardware is much more reliable than the best analog! The result is that maintenance costs drop precipitously.
The show will go on
In this fabled year of 2001, it is fair to say that some digital consoles can have problems that are relatively unknown in the analog world – specifically problems of software instability. We have all heard all-too-true stories about digital consoles that have crashed in the middle of live productions, causing an unfortunate loss of audio. However, CANTUS is never mentioned in these stories. Why? Because CANTUS simply does not crash.
Unbelievable, how can a system working with microsoft windows (no offense, Bill!) be that stable? It's because the PC in CANTUS doesn't handle any audio at all – it's only used for saving set-ups to disk and for updating certain configurations. All audio control and processing is handled by the CANTUS hardware and software. So even if Windows crashes, the show will go on. CANTUS will stand firm, keeping you »on air«.
Still a Normal Console
You might wonder if anything remains the same as we go from yesterday's analog consoles to today's CANTUS Digital Console and the answer is certainly »YES!«. The mixer still sits down at what he or she will recognize as a real audio console, not some screen based semi-pro thing. There are actual PFL buttons, solo buttons, hiresolution meters, etc. And, just like the older analog consoles, the maintenance staff will be happy to see redundant power supplies and fully hotswappable cards throughout the system. Of course, there are lots of other benefits offered by CANTUS digital consoles – all of which help to make it a must to go digital today. Not with HAL, but with CANTUS!
Radio Vatican has been spreading Catholic teachings across the globe since 1931. But closer to home, until recently, its antenna pole was spreading something else. Such is its field strength that it was inducing noise in every copper wire in the Vatican. Today, that interference is no longer a problem thanks to a NEXUS at the Vatican.
Spreading the Word
Not so long ago, Radio Vatican's switching room looked more like a museum than a modern control centre. Sepia tinged photos of its inauguration back in 1931, revealed that little had changed in the room in almost seventy years. Indeed, the microphone pope Pius XI used for the first speech on that inaugural day still exists, and is on public display in the Vatican. So why did the Vatican wait so long before bringing its central technology up to date?
Lack of space
The answer to this question has much to do with the Radio Vatican's unique circumstances, which present specific problems that are unlikely to be encountered by any other broadcaster. For a start, space is limited, so the radio's studios have to lie outside the Vatican, at the Palazzo Pio in Rome. This building hosts a modern computer-networked audio system for recording, editing, and broadcasting. Meanwhile, the transmission pole and the switching room are located on Vatican soil, at the Palazzina, some 3 km inside the city walls. Here, lack of space dictates that the transmission pole and the switching room lie within walking distance of each other.
Until now, programmes recorded and edited at the Palazzo had to be mastered on tape and carried to the switching room inside the Palazzina in order to be aired. A fixed line between these two buildings was out of the question, given the strong noise produced by the transmission antennas: the field strength was too much for conventional analog copper wires to handle.
A Test of Faith
Another drawback was the fact that the antenna has to be rotated, according to the area the broadcasts are to cover. Around noon, the antenna faces the switching room, where all the audio signals are handled – with a radiation efficiency of 80 V/m.
From a theoretical point of view, the Stage Tec crew, however, was confident that even these levels of exposure would pose no problems for NEXUS, and they came to The Vatican to put their faith in the product to the test.
The Vatican borrowed a NEXUS device for four months, and after a thorough series of tests, the system's noise resistance was proved beyond doubt: absolutely no interference or beating could be measured. The only things present were the excellent audio specs of the NEXUS' input stages. The reasons for this are the high common mode rejection of the analog inputs and outputs on the one hand, and the characteristics of fibre-optic cable which is largely immune to electromagnetic interference, on the other.
Networked and Integrated
Today, a fibre-optic line links the studios to the switching room. Either side is equipped with two NEXUS base devices that are connected to each other via Stage Tec's proprietary FOC format. The completed programmes no longer need to be carried physically to the other side, but are now simply sent down an optical line. The Vatican uses mono-mode cable for bridging the distance of several kilometres.
Apart from linking the production centre to the switching room, NEXUS also handles several other tasks: for example, it distributes the various signals and converts them into different formats in the studio complex as well as in the switching room. In comparison to the old system, NEXUS has allowed the Vatican to save up 80% on cable runs, with the additional advantage that the NEXUS can be controlled by the on-air system with a precision of less than a second. Furthermore, the NEXUS' controlling PCs have been integrated into the production network. The multiuser software and graphic user interface run on the same computers that are also used for recording and editing the radio's material. Finally, the XDSP plug-in boards connected to the NEXUS also handle processing of the broadcast signal's dynamics, thereby rendering the station's former 32 limiters obsolete.
For the planners at Radio Vatican, it was an undeniably big decision to carry out such a momentous overhaul, involving the replacement of tried and tested equipment. A great deal of preparation was required, as well as the support of all those in charge at the station. Florenzo Petitta, the technical production manager, Piero Iorio, the technical manager of the switching centre, and Maurizio Venuto, the technical director of Radio Vatican, jointly voted in favour of NEXUS. However, don't expect the NEXUS system to remain unchanged for another seventy years. On the contrary, such is the success of the new system that plans are already underway for the first expansions of the system in the shape of additional base devices.
Radio Vatican Today
According to Radio Vatican's multilingual information pack, its main aim is »to link the heart of the catholic world with all countries around the globe«. Back in 1931 programmes were broadcast in Latin, to a limited audience. But today, Radio Vatican broadcasts in 53 languages, and to 32 different territories of the world. The huge programme offering is prepared by 60 engineers in 14 control rooms, and countless reporters and journalists working in all the various languages. Broadcasting on short wave, medium wave, FM, and via satellite – Radio Vatican truly covers the world.
Known for its big CANTUS and NEXUS systems that are often used in largescale networks, Stage Tec has now developed the small TrueMatch RMC. Here Jakob Händel, one of the system's first users, explains, how this compact converter is big on features.
28 Bits in Your Bag
There is no device I think about less during a project than the TrueMatch RMC. Once it is set up on stage, all signals are transmitted directly in the MADI format to my Pyramix hard disk recorder via a single BNC cable. It is safe to say that presetting the microphone input levels on stage – the only thing I still have to do manually – has become a routine job after some 150 studio and live recordings over four years.
Also for Fly-Ins
I used to work with a device looking similar to a NEXUS, that is to say, one without a user interface at the front, only controlled by a laptop computer. Since updating the system with the TrueMatch RMC panel, I have also used the device for other applications.
One of them is transferring audio material on analog tape to my hard disk system. For such jobs, the operation panel and accurate level meters are particularly helpful, while the combined XLR/phone sockets have proved real trouble-shooters during quite a few studio sessions.
The aforesaid configuration with MADI card is, in fact, a custom solution for expanding the NEXUS. I now have two output formats that I can use in parallel: MADI and AES/EBU, or to be more specific, S/PDIF, which we chose for reasons of space in our already full device. By returning the audio from the editor via MADI, we can distribute the AES/EBU outputs ad lib across the studio, thus using the TrueMatch RMC as an active splitter.
I can no longer imagine working without this device. Since 1997, it has consistently proved its value for about 30 big projects abroad. One of many examples is a production for counter-tenor and organ in the Tokyo area. A TrueMatch RMC and a Genex MOD recorder, in two flightcases, weighing only 26 kg, plus a backpack with aluminium stands, were all it took to work with eight channels in 24 bits back in 1998. And there was no charge for excess luggage at the airport. By the way, the combination of these two devices has proved reliable even under the most diverse power supply conditions and for a variety of applications.
In particular, the Japanese counter-tenor production revealed the A/D converter's exceptional accuracy. In pianissimo passages, extremely low-level background noises from outside the wooden church become audible. There was distinct hint of chirping birds in the recording; such noises are normally drowned out by the noise floor. The CD, titled Laudate Domino, was released on the Berlin-based Carpe Diem label. With its TrueMatch RMC, Stage Tec has defined a new standard for mobile use of multichannel converters. Thanks to its amazing sound quality and awesome dynamic range, one feels the need for even better microphones with a lower noise, because right now, the converter beats many a microphone!
The TrueMatch RMC
The TrueMatch RMC is a high-quality, 28 bit analog-to-digital converter. Based on the patented Stage Tec TrueMatch principle, it provides high-fidelity quantization. Thanks to its 28 bit resolution, this converter is capable of covering a dynamic range of 150 dB, which allows the user to directly connect virtually any signal source – from high-level line signals to straight microphone signals, with the additional advantage that analog microphone preamplifiers are no longer necessary, so further lowering the noise floor.
The TrueMatch RMC's optical appearance is reminiscent of a NEXUS device: designed as a rack frame with 9 slots, it accepts various boards, such as A/D inputs, AES/EBU, Y2, ADAT, S/P DIF, and TDIF interfaces. Unlike the NEXUS, however, it cannot be expanded via a second rack module. The TrueMatch RMC provides part of the NEXUS's functionality, albeit on an altogether different level. With a simple control program that runs on any PC, the inputs can be freely assigned to the desired outputs. After inserting several digital interface boards, this device can be used as a no-frills format converter-cum-router.
The TrueMatch RMC comes with additional features, such as digital post-amplification, a high-pass filter, phantom power and phase inversion. In a way, the TrueMatch RMC could be considered the entry-level device for recording studios. In fact, only one restriction applies to working with the A/D: it does not accept an optical card for connection to a CANTUS or NEXUS device. Unlike on a NEXUS, the input and output addresses required for managing such optical links are already used by the function that drives the LED level meters.
In the good old analog days, huge audio crossbars and patch bays dominated the switching room. Not anymore. Today, one German broadcaster demonstrates how an entire central audio switching system can be transferred to just two 19" racks – courtesy of a new STAR …
Stage Tec's new product came just in the nick of time for SWR Stuttgart, the second biggest member of the German broadcasting association ARD. It was while making plans for the new SWR system that Marc-Oliver Brehm learned about NEXUS-STAR. At the time, he was considering the use of a campus-wide MADI network and a large, central main switching room matrix for MADI signals. Though the new routing element of the NEXUS family was still only at the design stage then, its features matched the radio station's requirements, and it soon became clear that SWR would be the first NEXUS-STAR user.
Technically, the NEXUS-STAR is a node inside a decentralized audio network. Locally installed, traditional, NEXUS base devices and digital high-performance devices with MADI interfaces are connected to SWR's NEXUS-STAR. This allows it to distribute the signals in a STAR configuration from any source to any output on the premises.
The NEXUS-STAR provides two interface types: MADI and the proprietary FOC NEXUS format. The latter is usually used for connecting several base devices with one another. Unlike MADI, it is a data interface, rather than an audio interface, designed to manage the networking capability of all connected NEXUS devices. Each NEXUS device is aware of the exact configuration of all other NEXUS units in the network, thus providing remote control of all inputs and outputs from any NEXUS device.
No Networked Control
In most large-scale audio networks, decentralized control is explicitly requested. This was not the case at SWR, or at least not entirely. The FOC link with the ability to remotely control the NEXUS devices was selected only for certain parts of the NEXUS network. These are the connection of external lines, or all the other tasks managed by the main switching room itself. The connections between the main switching room and the control rooms – as well as SWR's so-called basic network, which is used for central jobs such as program transfer or linking to the external studio »Villa Berg« – are controlled via digital audio lines rather than a data line.
The advantage of this connection type is that the control rooms cannot change the settings in the main switching room: neither can an engineer in the production department shut down an on-air line. In addition, local maintenance operations, modifications, or updates cannot affect what is going on at the main switching room. The only connection between the main switching room and the various sub-networks is via a fixed number of MADI lines. The switching room, however, is unaware of the local NEXUS configurations in the studios, which means that the local networks can be expanded ad lib and adapted to new requirements, without the need to upload the new NEXUS configurations to the main switching room every time.
The first to go digital at SWR were the control rooms. Old analog rooms were replaced with digital ones, which were in turn connected to the analog switching rooms via MADI. This compact format – 64 sends and returns via one optical pair – comes as standard on all current digital mixing consoles, thus making it the obvious choice in Stuttgart.
SWR currently has six digital control rooms with one MADI link to the main switching room each; three MADI lines remains for future requirements. Seven analog control rooms are also connected to the main switching room via MADI. These control rooms share two NEXUS base devices, which, in addition to their main tasks, also provide local routing capacity. In the same way, the so-called SWR basic network for all the central tasks such as station identification and central program transfer, is connected to the main switching room. Together with the programme selector, a special feature at SWR, nine base devices and seven digital control rooms with 24 MADI lines of 64 channels each, are linked to the NEXUS-STAR in the main switching room. For that, the STAR is fitted with six MADI cards, which means that not even half its capacity is currently in use.
The Programme Selector
How do you implement a simple, yet versatile programme monitoring system in a big broadcasting corporation? SWR found the answer to this question. It used a programme selection system based on the internal telephone system. From 160 locations across the premises, journalists can press a few buttons on their telephones to route the stereo signal of one of the 40 available radio and TV programmes, or any other source provided via the NEXUS network, to their monitor speakers. For the staff, it's that simple, even though technically it is a much more complex system. The telephone commands have to be interpreted by special software, developed by Veith, before the requested signals are routed to the NEXUS. Three base devices have been installed for this monitoring system. In response to the telephone commands, they now route the desired signals to the cable runs that have been around since the good old analog days.
In addition to the internal sources at SWR, there are also external sources and outputs to take into account, such as the link to the common ARD broadcast network (Sternpunkt), and, more importantly, the broadcast lines. These are connected to the STAR network via one base device with NEXUS FOC connectors. The internal »heart« of the SWR audio network therefore comprises a STAR and a normal base device. For safety reasons, and to give maximum flexibility with respect to future upgrades of the main switching room, this core is available in a redundant configuration: two base devices that receive external lines via passive splitters and are connected to the external outputs via priority switchers; and two STAR units connected to the MADI lines on the premises. During normal operation, only one STAR/base device pair is used, while the second can be activated at the press of a button. For the implementation of this specific design, SWR took advantage of a new passive fibre-optic splitter and switch. Both the splitter and the switch take care of distributing the incoming MADI lines to STAR elements and the outgoing MADI lines of the currently active STAR.
Timer for NEXUS
NEXUS – whether with or without STAR – switches audio signals instantly. In a main switching room, however, timerbased connections, with the possibility to book the required lines in advance, are necessary to survive a regular working day. For such timer-based information, SWR uses Veith's RoSy routing system whose predecessor had already proved its reliability with the analog system. RoSy allows for time-specific reservations and carries out collision checks while establishing the booked connections. It automates certain connections, for example the connection of the on-air signal to the required sound processor, and broadcast limiter – before the signal actually reaches the outgoing line. It provides extensive control over the NEXUS by routing stereo signals to two NEXUS channels, producing mono conversions where necessary. RoSy uses its own client/server network. Currently, it is only the main switching room that is fitted with working clients, while monitors in the control rooms allow the engineers to keep track of the current status of outgoing lines. Additional clients can be installed in any control rooms as, and when, necessary. Such clients would allow operators to establish connections from outside the switching room – and to remotely control NEXUS from almost anywhere in the building.
A STAR is Born
For now (spring 2001), NEXUS-STAR is used in parallel with its predecessor, the huge analog Ghielmetti and Siemens matrix. The complex RoSy control is still being tried and tested, and engineers felt it would be foolish to run unnecessary risks.
Yet, even at this stage, the advantages of the new system are already apparent. These are the typical advantages of working with NEXUS: extremely short delays; a compact system; easy maintenance; a high degree of reliability; and a transparent user interface. What is new, however, is the exceptionally vast routing capacity. Says SWR's planning engineer Marc-Oliver Brehm: »The sheer size of NEXUS-STAR allowed us to be generous with our control room links.« A great performer in a modest guise – now there's a real STAR.
Facts about NEXUS-STAR
The NEXUS-STAR is a powerful routing component for largescale audio networks used by the likes of broadcasting corporations, trade fairs and other large installations. The NEXUS-STAR accepts up to 16 plug-in boards, each of which can route 256 audio signals. A fully expanded STAR device therefore provides 4,096 inputs and 4,096 outputs, with over 16 million routing points. To cater for even bigger installations, it is possible to run several STAR devices in cascade. Any input can be routed to any output, while the user can choose between point-to-point and pointto- multipoint connections. The NEXUS-STAR currently supports two interface card formats: the Fibre-Optic Connection (FOC) for connection to NEXUS units; and boards with four MADI connectors. The MADI format allows the user to directly connect big digital audio systems, such as mixing consoles and multitrack recorders. Like all NEXUS units, the NEXUS-STAR works synchronously. Thanks to its internal TDM technology, the system only generates a brief, constant, delay of a mere six samples for all signals. This low latency makes the system suitable for critical applications, such as live broadcasts. During operation, the entire NEXUS network conducts automatic tests. In the event of a line breakdown, the system automatically switches to a redundant line. Furthermore, all cards are hotswappable, thus providing the highest degree of reliability you can imagine. Yet another advantage of the NEXUS-STAR is that its power requirements add up to a mere 160 W for a fully expanded system, which means that no cooling fans are necessary. Yet when you look at this giant, all you see is a dwarf: the whole powerhouse fits into 6U of rack space and can be installed virtually anywhere.
»Concert Hall Berlin«, the extensive public venue with three main halls and countless foyers, attracts large audiences for its events. But it is also proving to be much more than a concert hall. An advanced audio system makes it a great venue for radio broadcasts.
Hall of Fame
Even in Germany's cultural capital Berlin, where there are always so many productions on offer, the varied programme of Concert Hall Berlin at the Gendarmenmarkt is always popular. Such is its reputation, that radio audiences are also eager to enjoy as much as possible of what this public institution has to offer.
On an almost daily basis, the Berlin-based radio stations come to the hall for live recordings. Sometimes there may even be two stations, such as the SFB and Deutschlandradio, covering the same event, simultaneously. Deutschlandradio, incidentally, sources the majority of its live recordings from the hall.
Not suprisingly then, broadcast considerations were high on the agenda when the hall's audio system was renewed in late 2000 and early 2001. And the result was that the hall opted for a big NEXUS network and several CANTUS consoles in a flexible setup.
Telecom Link Included
Three main stages of the Concert Hall – the big hall, the small hall and the Music Club – are covered by five NEXUS base devices. All microphones can thus be connected to a near-by NEXUS unit and routed to the house network. Live recordings take place in the two fixed studios, each with its own base device. Alternatively, the radio station can use an OB van, and connect it to a dedicated base device, which doubles as broadcast output for the telecom link.
This already impressive audio network is built around yet another base device that acts as a central router. For this, it contains only NEXUS-FOC cards, which are used for connecting the various base devices to one another. The audio network, with its 11 base devices – together with a mobile base device with three connection locations in the house, and one device for public address applications – is extremely impressive.
Two Plus One
For broadcasting purposes, the two production control rooms have been fitted with CANTUS consoles – a big, 64-channel console in the main control room, and a 48-channel console for the smaller production control room. These control rooms are mainly used for productions rather than for public address purposes. Nevertheless, they are linked to the stage via a video line, and so provide at least indirect visual contact.
More sophisticated public address applications and musical cues can be better controlled directly from the hall. There are several possibilities for doing so: for a start, the engineer in the hall can use a laptop for remotely controlling the DSP resources of the NEXUS. For small-scale speech PA applications, this approach is most suitable, because the laptop system not only allows the user to balance the levels, but also to set the delays and equalization. In the event that this simple, mouse-driven operation of individual parameters is not enough, a slave console can be set up at various spots in the hall – with a twist: in split mode, the slave console can be operated independently of one of the two main consoles.
This allows best use of the two control rooms and increases the venue's flexibility for the radio stations that wish to work on-site. To ensure that connecting the slave console is as simple as possible when things get stressful, the Concert Hall uses an OMUX unit. This is an optical multiplexer with various slave console sockets that automatically route the currently selected connector to the respective main console.
The Concert Hall Berlin
The name »Concert Hall« is misleading, because this venue not only hosts concert performances, but also many other events. The Music Club, the smallest of the three halls, for example, is also used as a small studio stage, where afternoon performances for children and families take place. The main hall, with its majestic organ, is used for a variety of events, although concerts certainly account for most. All kinds of concerts, from piano recitals to symphonic works with big orchestras, are staged here. The small hall, which despite its name still has 450 seats, is perfect for chamber music and ensembles of up to 20 musicians.
Synchronicity in Three Rooms
Audio engineers can work from three different locations: the main control room; the small control room; or the locally installed slave console. For the venue's regular operations, this system would probably seem over the top. However, such is the level of interest among broadcasting stations, that even the current setup can become tight. If only one radio station covers a live event, while two events requiring audio support take place simultaneously, the flexibility of the slave console becomes indispensable.
That desk is then used as an almost independent unit, which, of course, is no problem when working in split configuration. This allows for working on three different events simultaneously at the Concert Hall. And if the current setup is not enough, two smaller events can share a console.
The staff of the broadcasting stations that regularly work at the Concert Hall Berlin are intimately familiar with the CANTUS control rooms. In fact, Deutschlandradio, the station that uses the commercial studio at Concert Hall most often, sent its audio engineers to Stage Tec for additional training.
But even »untrained« sound engineers have little problem working with the desk, since the audio department at Concert Hall takes pride in thoroughly preparing each project. Installing the microphones, setting up the NEXUS, and configuring the CANTUS are all tasks handled by Concert Hall engineers – so that Concert Hall not only renders services to the audience but also to broadcasting corporations.