Lee Austin, program director, and Cathy Ives, general manager, of Utah Public Radio photo on the air through a Logitek networked audio system.
So the time has come for you to come up with a plan for a new studio facility. Perhaps the station is moving; or maybe you're just planning on a rebuild of the current facility. Are you dreading the prospect? Finding ways to put it off another year? Or are you ready and anxious to dig into it? Thinking about sticking with the good-old-tired-and-true methods? You know all about analog. Why go with this fancy digital stuff, right?
Sometimes it's hard to toss out our old analog ways, to send consoles that cost a fortune (back in the day) to the storage room at the transmitter site (or wherever your equipment graveyard is) along with the 10-input-by-2-output mechanical switchers and stereo DAs and expensive analog tape decks and turntables and cart machines. (Need I go on?)
The reality is that there aren't that many analog consoles made any more, and installing them, in the old-fashioned way, just isn't that economical. And aside from spending more on the installation, you won't end up with the kind of features that so many radio stations have now. In practice you would be doing a disservice to your air staff and listeners.
So, if you are willing to entertain the idea of a digital console, you will also need to decide if you want to make use of plain old TDM or an IP-based system. I'll discuss the ways in which they are similar, and different. Hopefully at the end you'll be comfortable with the idea (just in case you aren't already).
Not a console anymore
The very first thing to realize about a digital console is that it is frequently not a console in the old analog sense of the word. For the most part (though there are some exceptions) the digital console is nothing but a human interface; a place from which your talent or board-op runs the show — telling the real guts of the system what to do and when. For the most part, all the same controls will be available via a GUI on a computer somewhere else. The GUI is used by someone with more training, of course, and mainly serves to configure (or program) the system.
The real guts of the system I referred to above are quite often called an engine or audio engine, and they perform the most basic functions of the system. These include providing a way for audio to get into the system, a way that sources get added to a bus, a way by which the mixing of elements into a bus can be done, and finally, a means by which the bus gets out of the console. This unit lives in the technical core of the radio station, and it will also perform the role of routing switcher, thus essentially replacing all the DAs that were needed at one point.
The digital radio studio looks and feels very much like its old analog counterpart, and has all the same functionality (even though most of the work is not done in the studio itself). For example, the talent will still need meters, monitors, headphones and a cue speaker. There will still be devices that live in the studio with the talent/board-op, such as microphones, CD players, EAS units, skimmers and whatnot. This necessitates a means by which audio ins and outs, and remote controls where necessary, can be integrated into the audio network even though they are not physically located at the station's technical core. The manufacturers of the systems described all have that capability, of course, though there are two principal technologies used to do it (both to be addressed below).
So before we get into manufacturer specifics, let's review the major features found in digital consoles/router systems: The hub of the system (usually called the router, engine, audio engine or mainframe) performs all the mixer functions under the direction of a control surface; the router aspect of the system for the most part eliminates the need for DAs and simplifies source selection on the studio control surfaces; dynamic mix minus generation is a common feature, though not universal; routing of remote controls; the combination of control surface and scaled-down system interface (satellite) can often serve as an independent system, providing system redundancy; and the computer used to program the system can be placed on a network, which allows the administrator remote access.
Time domain multiplexing is the method by which most of the manufacturers' devices communicate amongst themselves. Physically, they are connected by either a CAT-5 cable (though not using Ethernet) or by way of fiber optic links. So even though the physical links are made of commonplace materials (like CAT-5 cables and RJ-45 connectors), the protocols for communications are proprietary. This single link (or spoke) greatly simplifies studio construction as well.
Digital console manufacturers
Wheatstone: The Bridge system has all the features I have mentioned so far. Basically there are three main elements to its system: the Bridge; a console (or control surface) and then the Satellite, which is a scaled-down version of the Bridge itself. The Satellite lives in a studio, allowing audio ins and outs, remote controls, etc. The Bridge lives in the technical core, and is the hub in a spoke-and-hub topology. Wheatstone gives the end-user many options in the specific physical means by which connections are made in and out of the Bridge; the most typical would be DB-25 connectors, but 110 ohm AES3 on RJ-45 is also an option, as well as 75Ω unbalanced AES3-ID via BNC connectors. Cage-to-cage connections can be made via CAT-5 or fiber optic jumpers. Notably, Wheatstone offers an entire family of control surfaces designed to have a particular functionality, such as an air studio (Generation 5), a production room (Generation 9) or a voice-tracking room (Generation 3).
SAS: Whereas many manufacturers started off building consoles, SAS started out making routers and has subsequently added control surfaces to its list of offerings. The 32KD system is its showpiece product, and is based around the 32KD mainframe router, which is obviously the hub in the spoke-and-hub architecture. The far ends of the spokes consist of the combination of the Rio, which is 2RU studio unit that allows for audio ins/outs, GPIO and serial communications, and Rubicon control surface. The Rubicon is a modular system, configurable from eight to 40 modules wide, and is particularly notable for its simple layout and similarity (at least in appearance) to the classic analog consoles. A functionally scaled-back version of the Rubicon known as the Rubicon SL is available as well for less demanding applications. Finally, for the simple applications like a news or traffic position, or even a voice-tracking studio, SAS offers the Rubi-T. It is referred to as a mini-console surface, but at the same time, it has the features of most any other control surface, including input source selection, bus assignment, and full-throw length faders.
Harris: The Vistamax digital audio networking system is Harris' offering — and like SAS, Wheatstone and others — is built on the spoke-and-hub topology. Vistamax is the actual hub, and like other systems mentioned earlier, it's completely modular and scalable. The user chooses the particular modules needed based on their system design, and plugs them into the mainframe, located in the technical core of the station. The Harris solution to the far end of the spoke is different though than others, because the three consoles currently offered (RMX Digital, Stereomixer Digital, and Netwave) are truly consoles — with audio inputs and outputs, like the legacy consoles they are meant to replace. This architecture allows them to operate on a completely stand-alone basis. They can be integrated into an audio network by means of the Vistamax system should the user choose to do so; and if so, the audio resources of one console are available throughout the entire breadth of the Vistamax system.
Logitek: Digital Audio Engine has most of the common engine features we've discussed up to this point. The mainframe is modular, like the others, but all the connections are made from the front of the unit. Logitek offers multiple control surfaces that work with the Audio Engine: The Mosaic, The Remora and the Artisan. The Mosaic is a modular system (two faders per module) that can be as wide as 32 modules and as narrow as 10. While the Audio Engine obviously handles the audio ins and outs, the remote controls for Mosaic are located on the power supply unit. Remora is a slightly smaller surface (with configurations from four to 22 faders) and has an interesting capability of being physically separated into two pieces. This control surface can also be set on top of a table; a cut-out isn't necessary. Finally, the Artisan digital: this surface can be up to 32 faders wide. One particularly notable feature of Artisan is that the channels can accommodate 5.1 surround (and of course either stereo or mono). The Vscreen software application allows the user to set up a video monitor that will serve as a metering bank; but in case that doesn't suit you, meter bridges are available as well. And finally, if you want to go beyond that, you make use of a software application for the audio engine called Vmix virtual mixer. This allows you to use a GUI for full control; no control surface is necessary at all.
Klotz Digital: As part of a networkable audio routing system, the Decennium standard console is supplied pre-configured to simplify installation and set up. The console is modular and expandable, and the configuration software allows it to be customized as needed. The Decennium audio engine includes on-bard DSP to provide voice processor, parametric six-band EQ and dynamics on each channel. Each channel strip features a rotary encoder with integrated push button and a 16-character display that can be used for source selection and channel-related parameter settings. The control surface is available in 4-, 8-, 12-, 16-, 20- and 24-fader frames.
Studer: The On Air 3000 and On Air 500 are available in consolidated frame and Modulo versions. The Modulo divides the fader and meter bridge components into sections that can be mounted into furniture. At the 2008 NAB Show, Studer added the On Air 2500 to the console family. The 3000 interfaces with an audio engine, called the S Core, while the 500 and 2500 can stand alone or talk to the Studer engine. The 500 is available in six- or 12-fader versions. The 2500 is available in 12-, 18- and 24-fader versions. The 3000 can be outfitted with up to 48 faders in three- or six-fader banks. In addition, the 3000 has three main stereo mix buses plus an audition facility, four stereo aux. buses, 16 mix-minus sends, configurable as auxiliary sends and three independent studio monitoring circuits. All models include dynamics and EQ.
A different approach
Up to this point, we've talked about TDM-based systems that communicate via proprietary systems. Generally speaking, these systems make use of CAT-5 cable and RJ-45 connectors (or fiber) as their means of physical connection. However, there is another way. Livewire is a protocol developed by Axia, and it makes use of Ethernet for communications between devices. The audio network is essentially identical then to an office network, using the same cable, connectors and Ethernet switches. Various devices are added to the network simply by adding them to the network via their Livewire port.
Axia offers the Element, which is the control surface portion of the Axia Livewire network. This surface can be built as small as two faders and as large as 30 faders in one surface, or up to 42 faders in a split-surface configuration. (Smartsurface is a 16-fader, low-profile control surface also offered by Axia.) The Element comes with four stereo program buses, four stereo aux buses and provides for as many mix-minus feeds as there are faders on the control surface. 5.1 mixing capability comes as a standard feature. Element (or Smartsurface) works in conjunction with the Studio mix engine; this is the part of the system that lives in the technical core of the station. By placing an Axia node (microphone, analog, digital or GPIO) in a studio, the user allows for a means by which microphones, CD players and whatnot can be interfaced with the audio network. (Some manufacturers, such as Audio Science and IDC are building Livewire interfaces into new products.) System programming is done via a proprietary application known as Pathfinder PC.
Radio Systems has licensed the Livewire technology from Axia, and now makes the Millenium-D console that is truly a console in the more traditional sense. The Millenium-D comes in six-, 12- or 18-channel versions, with analog line and mic level inputs, digital inputs and outputs, plus the livewire port. A system that is made up of at least two Millenium-D consoles then makes up an audio network system. This is considerably different than the spoke-and-hub topology I've referred to so many times previously; the Radio Systems architecture could more accurately be described as peer-to-peer. Audio made available at one console would be available at the other via the Livewire connection. Like the Axia system, the audio network is expanded by the use of an appropriate Ethernet switch.
But Axia doesn't have the exclusive domain over Audio over IP routing and mixing systems. N/ACIP, a standard developed by the European Broadcast Union, creates a standard for IP interoperability. At the NAB Show, SAS unveiled the Transend IP to allow the 32KD router to communicate with audio over IP networks. In addition, several companies introduced their own AoIP ideas. Wheatstone unveiled the E2 routing system, and Logitek provided a preview of its AoIP engine that will be available later this year. The IP approach appears to be gaining acceptance.
Because studio moves and builds don't happen that often, it's important to future-proof the new studio facility to the maximum extent possible. Focusing on the newer technologies, and foregoing the old, is the best way to do that. The ubiquitous nature of CAT-5 cable has made the job of the studio designer and the studio builder easier. The coupling of the increased speed of a studio build with the new common feature sets of digital consoles is bound to have a beneficial effect on the station's programmers, and thus listenership.
Irwin is chief engineer of WKTU, New York
Manufacturers of audio consoles and router systems