FAQ

1. Why build an audio network? View Answer

2. What types of audio networks exist? View Answer

3. What are the advantages of a Wheatstone Composite Network? View Answer

4. What audio challenges exist in the HD environment? View Answer

5. What is the AE-Net ? View Answer

6. Why are Vorsis processors unique? View Answer

7. What are the newest alternatives in broadcasting? View Answer

Why Build an Audio Network?

A networked audio system is a collection of components designed to accept audio input signals, manipulate them with processes such as equalization and mixing, and make them available throughout the system. It differs from traditional audio consoles and routers in that a mechanism is provided to transport audio in digital format throughout the system via some sort of high speed interconnects. This ability to transport audio around without a complex and expensive wiring infrastructure of patch bays, tie lines, punch blocks, distribution amplifiers, and match boxes makes a networked system much easier to design, maintain, expand, and modify.

In a typical networked system, some sort of localized input-output satellite rack or node is located wherever there are audio source or destination devices. The inputs and/or outputs of these audio devices are wired to this local rack with generally short, simple, and standardized cables. The local racks in turn connect together via the high speed interconnects which are usually Cat-5 or - 6 cables that may already exist in the facility. In the Wheatstone system, each one of these Cat-5 cables can carry 128 audio signals and simultaneous logic and control information. One of these cables is usually ample for all of the audio and logic needed in a control room or studio. A system installation becomes mainly mechanical; i.e. mount the equipment into the racks, plug the audio device wiring (which can frequently come with the system) in, and plug in the network cables connecting the rooms together.

In the Wheatstone system, once installed, every audio device, every mix, and every logic function is instantly available through out the whole system. The long hours of the past spent crawling behind and under consoles to wire up input connectors and logic ports are not needed. And should a cross connection change be required it can be executed in seconds with a mouse click.

A further benefit of a networked system such as the Wheatstone Bridge is that all system configuration and control settings can be managed from one central point via password-protected software. All connections, settings and functions are always available for inspection, activation, or modification. Mapping connections, changing signal names, setting up a logic function, adding more channels, changing a format to surround sound, implementing an intercom, etc. all can be managed in the Wheatstone system on line and while the system is ON AIR. Or if preferred changes can be made off line (say while on the flight over) and then later uploaded to the system in seconds.

What Types of Audio Networks Exist?

Router based: A router-based system is built using a centralized digital audio router with secondary or satellite router frames in studios and control rooms. Some of these systems have integrated mixing with control surfaces while others use separate consoles, which are then wired to router frames. In either case, once the audio has been brought in to the router, it is distributed to other frames via the high speed interconnects. Because the router handles all of the networked audio a major system constraint is the overall size or capability of the router and the size and capability of the satellite frames and their ssociated network links. The system capability must be large enough to handle all current and future audio requirements if it is to benefit from the advantages of a networked system. It can be difficult asserting whether the capabilities of the router are sufficient because in some systems router channels are needed unexpectedly, say to get metering information back to control surfaces, or to bring mixes back into the system, etc. Additionally, some router based systems handle logic functions directly within the system while others require an additional network and maybe even PCs to deal with logic. In larger systems, careful planning and investigation should be made to assure that the router is sufficient for the scope of the project. For router based systems that use traditional consoles, some sort of wiring infrastructure such as punch blocks is generally needed in each location due to the large number of fixed, inflexible connections required to the consoles. Depending on the type of router, a large punch block system may be required in the TOC as well to provide for cross connects and distribution amplifiers that may be needed to properly connect the output mixes.

In a typical networked system, some sort of localized input-output satellite rack or node is located wherever there are audio source or destination devices. The inputs and/or outputs of these audio devices are wired to this local rack with generally short, simple, and standardized cables. The local racks in turn connect together via the high speed interconnects which are usually Cat-5 or - 6 cables that may already exist in the facility. In the Wheatstone system, each one of these Cat-5 cables can carry 128 audio signals and simultaneous logic and control information. One of these cables is usually ample for all of the audio and logic needed in a control room or studio. A system installation becomes mainly mechanical; i.e. mount the equipment into the racks, plug the audio device wiring (which can frequently come with the system) in, and plug in the network cables connecting the rooms together.

In the Wheatstone system, once installed, every audio device, every mix, and every logic function is instantly available through out the whole system. The long hours of the past spent crawling behind and under consoles to wire up input connectors and logic ports are not needed. And should a cross
connection change be required it can be executed in seconds with a mouse click.

A further benefit of a networked system such as the Wheatstone Bridge is that all system configuration and control settings can be managed from one central point via password-protected software. All connections, settings and functions are always available for inspection, activation, or modification. Mapping connections, changing signal names, setting up a logic function, adding more channels, changing a format to surround sound, implementing an intercom, etc. all can be managed in the Wheatstone system on line and while the system is ON AIR. Or if preferred changes can be made off line (say while on the flight over) and then later uploaded to the system in seconds.

IP based: An IP based system is built using conversion boxes that take analog or digital signals in (or out) and convert them to (or from) Ethernet packets which are then distributed LAN fashion using one or more intelligent Ethernet switches that have been set up to manage the audio distribution. Although this sounds simple on the surface it is a complex process and requires attention to detail and careful planning. The Ethernet protocol was originally designed as a mechanism to distribute short bursts of data non- synchronously in a non-deterministic fashion. The protocol has an elaborate mechanism of collision correction and retries built into it because the designers knew some packets would not get through. Because audio data is very different in nature (a continuous stream of synchronized, time critical data) special constraints must be placed on the LAN and Ethernet switch to control the “scattered packets” tendency of basic Ethernet. Because these constraints can be inadvertently upset on a general-purpose network, it’s best to run such a system on its own dedicated LAN to avoid problems. These systems purport to save money by eliminating the need for a dedicated central router frame and by using an off-theshelf Ethernet switch; in reality a central frame or equivalent nodes are needed anyway to pull audio in and out of the system in the TOC. The costs associated with the Ethernet switches and extra cabling due to the inherent lower audio density plus the expense of the control software and PC total up to an amount that can exceed the costs of a controller card in a router based system. A typical IP system will actually have a large number of low density CAT 5 cables, I/O dongles, and power adapters to get it all wired in. On the other hand, for applications where the audio is either developed on or distributed to a PC, IP based systems allow you to connect directly with the LAN and avoid using audio I/O ports in the system and sound cards in the PCs, which can be a potential cost savings (depending on software driver costs, additional switch ports consumed, etc). Another sometimes unexpected cost is the time required to set up, configure and administrate these network devices; in a good sized system this can become quite significant. Although it might seem that IP based systems are immune from sizing constraints, that is not the case. Because of the extra addressing and timing baggage the packets require to “herd the cats”, IP based systems typically run their high speed interconnects with lower density (typically one fourth as many channels) resulting in many more cables being required. The bandwidth of the central Ethernet switch must also be sufficient for the number of streams required.

Composite: The Wheatstone Bridge system is a composite system. The system has a scalable audio structure that distributes and manipulates audio data synchronously and coherently for low latency and true audio fidelity. The system size constraints are very generous; the hardware can support over 24,000 simultaneous audio channels within the card racks of which over 3000 channels can be distributed across the network at once.

The network interconnects use standard Cat-5 cable (or fiber), and because the audio distribution is deterministic the signal density is very high, with 128 channels of audio, plus logic and control signals available on every cable. Because this audio core is not Ethernet based and uses embedded control, it is immune from accidental or even deliberate network disruptions or those cases such as Automation, where audio data plays from storage on a PC, the Bridge system can have Ethernet portals that allow direct connections to a LAN. Using the Wheatstone AoIP driver, any Windows based PC or device can send and receive multiple audio channels (up to 8 stereo each way) via its NIC card. These ET portals convert IP based audio into the proprietary protocol of the Wheatstone audio structure. They are scalable, and systems can be built with multiple portals, each supporting 64 audio streams.

The Bridge system also integrates logic and control. Physical logic I/O cards can be installed in any rack, making it convenient to do control wiring at the location of the controlled device (no more multiwire trunks pulled between rooms!) and logic functionality is fully associated with the audio signals. If an audio device is routed to a different control surface channel or even a different surface, the logic functionality can route simultaneously with no user interaction. Finally Wheatstone has created and made available a sophisticated Ethernet control protocol for the Bridge system.

What are the Advantages of a Wheatstone Composite Audio Network?

The Wheatstone Bridge system is a composite system. The system has a scalable audio structure that distributes and manipulates uncompressed audio data synchronously and coherently for low latency and superior audio fidelity. The system size constraints are very generous; the hardware can support over 24,000 simultaneous audio channels within the card racks of which over 3000 channels can be distributed across the network at once.

The network interconnects use standard Cat-5 cable (or fiber), and because the audio distribution is deterministic the signal density is very high, with 128 channels of audio, plus logic and control signals available on every cable. Because this audio core is not Ethernet based and uses embedded control, it is immune from accidental or even deliberate network disruptions. The Bridge system may be fitted with Ethernet portals that allow audio playout or recording to devices already connected to an Ethernet LAN.

Using the Wheatstone AoIP driver, any Windows based PC or device can send and receive multiple audio channels (up to 8 stereo each way) via its NIC card. ET portals convert IP based audio packets into the proprietary protocol of the Wheatstone audio structure. AoIP is scalable, and systems can be built with multiple portals, each supporting 16 stereo bi-directional audio streams.

Standard 24-bit digital audio data used within the Bridge system also integrates logic and control. Physical logic I/O cards can be installed in any rack, making it convenient to do control wiring at the location of the controlled device (no more multiwire trunks pulled between rooms!) and logic functionality may be fully associated with the audio signals. If an audio device is routed to a different control surface channel or even a different surface, the logic functionality can route simultaneously with no user interaction. Finally Wheatstone has created and made available to all 3rd party developers an elegantly simple but powerful Ethernet control protocol for the Bridge system.

Many of the Automation providers now have direct control integration between the Bridge and their system via Ethernet; no hardwired logic connections are required. Because the Wheatstone Bridge has the flexibility to internally route and distribute all audio and logic, including all mixes, no expensive wiring infrastructure or punch block system is required. Each device can be wired directly to the system at its physical location with simple standardized cables. Wheatstone provides a number of I/O connector options to facilitate this. No expensive dongles or distribution amplifiers are needed, and all cross connects can be managed within the system via the provided GUI based administrative software.

Lastly, every system comes tested and preconfigured by the factory to the specifics of the project, so it is truly "plug and play". A large multi-station system will run right out of the box with no user involvement at all other than to unpack the components and plug in the power and CAT 5 cables.

Many of the Automation providers now have direct control integration between the Bridge and their system via Ethernet; no hardwired logic connections are required. Because the Wheatstone Bridge has the flexibility to internally route and distribute all audio and logic, including all mixes, no expensive wiring infrastructure or punch block system is required.

Each device can be wired directly to the system at its physical location with simple standardized cables. Wheatstone provides a number of I/O connector options to facilitate this. No expensive dongles or distribution amplifiers are needed, and all cross connects can be managed within the system via the provided GUI based administrative software.

What Audio Challenges Exist in the HD Environment ?

The advent of HD broadcast and other new technologies has changed the audio landscape substantially over the last few years. The audio console must now act as a central point of signal acquisition, processing, mixing, and routing for a diverse set of sources and destinations. Here are some key issues that Wheatstone Digital TV Systems help to address:

1. Digital Sources
Stations now have multiple AES sources of audio, both synchronous and asynchronous. Asynch sources such as CD players, Mini-discs, and DAWs are handled in our router by SRCs (Sample Rate Converters) on our digital inputs. Sources with sample rates as low as 8khz and as high as 192Khz are automatically converted to the master sample rate (usually 48Khz) of the overall router system. The Wheatstone Bridge Router also accepts an AES clock input, so it can run synchronously with other digital systems. This means that your Bridge Audio Network will be in synch with your house audio/video router.

2. Multi-Channel Audio
Every station handles their surround signals differently, but whether you’re using Dolby E or SRS encoding, you need to handle multiple channels of audio gracefully at the mix desk. All Wheatstone TV Surfaces allow you to define 6 discrete channels as one surround signal that can be routed to a single input fader and assigned to a single 5.1 output buss. Stereo and Mono sources (usually local content) can be mixed and panned anywhere in the surround field, so whether you’re passing network surround and mixing local signals or actually creating surround program material, our systems simplify the process. Upper end surfaces (D12 and D5.1) give you tools to “spill” the individual surround channels onto six discrete faders for signal rebalancing, and then “fold” those signals back into the original single fader at their rebalanced levels.

3. Delay!
With digital video comes delay. We’ve all seen the increase in “lip flap” that accompanies our new digital video path. Wheatstone systems give you the ability to compensate on a channel by channel, source by source basis for delays in the signal chain. Channel delay is easily and quickly adjusted on the fly in millisecond or sub-frame increments.

4. More Mix Minus
The transition to 2Ghz digital pathways for remotes and the inherent delay in that system means that stations now require more true mix minuses for remotes. No more sending program into the field! Wheatstone has always recognized that mix minus needs to be plentiful and easily set up on the fly. Operators need not scroll through menus or suffer through repetitious button pressing to assign or deassign mix minuses. Channel tallies give instant feedback as to what’s feeding whom. Direct IFB is available on every mix minus output, of which there are many. A 24 fader D10, for example, gives access to up to 56 mix minus outputs!

5. Processing
With a diverse set of input signals comes the need for flexible signal processing on every input. All Wheatstone systems ship with enough dedicated DSP to provided four band parametric EQ, compression/limiting, notch and hi/lo pass filtering, and gating (D12, D5.1) on all channels simultaneously. DSP resource is not dynamically allocated, so you will never run short of processing horsepower.

6. Control
Many stations are now moving toward automating certain dayparts. This requires an audio board that can follow automation commands. All Wheatstone TV systems have an IP based command protocol that allows for this control interface. Automation vendors can implement various levels of control, from simple channel fader control to full recall of show presets, input sources, and routing assignments. Ross Video is currently using our protocol for an interface to their Overdrive® system, and other vendors are welcome to add this functionality to their products.

All these factors combine to give you a powerful central point of mixing, processing, routing, and control in your Wheatstone Digital TV system. Contact us for more details on individual models in the Wheatstone TV line.

What is the AE Net?

The AE Net by Audioarts is a distributed digital audio and control network designed specifically for the Broadcast Industry. Engineer friendly, this system can be designed and configured as a powerful stand alone routing system or as a fully integrated mixing and control network with out D-75N consoles.

Our architecture allows for any possible combination of analog, digital inputs or outputs. AE Net is built using individual cards so you don’t end up with a large amount of unused inputs or outputs common with the “node” type systems. A single cat-6 cable allows you to move audio and controls signals from whatever source to whatever specific destinations via low latency, non “packetized audio” link.

The Audioarts Net 8 is the center for distributed your audio and control network. AE Net generates the system clock rate, stores system configuration files, controls all switching, and communicates via IP to our X-Y controller, software plug-in's and our automation partners.

The Audioarts IOC is a modular frame is capable of 32x32 Audio Channels and 24 Universal GPI/GPO ports in a compact 2 RU package. Audio inputs and outputs can be all analog, all digital or any combination.

Start with a simple IOC frame 16x16 analog & digital stand alone router, connect it to additional IOC frames and D-75N consoles and expand it into large digital network capable of delivering thousands of audio channels for our entire facility.

Why are Vorsis® Audio Processors Unique?

What is a general definition of an audio processor?
An audio processor is designed to be used by a radio stations to “color” the audio, and enhance it to make the audio more pleasing to hear, to increase the loudness of the station and to give the station a distinctive, unique sound.

What are the applications?
The main application is for live on-air radio stations. It can also be used for Internet streaming, and for post production studios that would like to hear how their music would sound on different radio station formats.

What makes Vorsis audio processors “unique”?
One big reason is the release of the award-winning Vorsis 31 band spectral processor. Up until now, no one has been able to do this successfully! Using 31 bands allows us to fine tune the audio and deal much more successfully with music that has been coded (which most music has). No other processor has the on-screen graphics display that we do. This is extremely helpful because as the engineer is making adjustments to the audio he can actually see what is happening to the audio. The GUI is set up in such a way that you are never more than 2 clicks away from any parameter of the system. You don’t have to dig through a tree format to get to the parameter you want to adjust.

What are the Newest Alternatives in Broadcasting?

Podcasting and LPFM are!

What is the general definition of Podcasting and LPFM applications?

A podcast is a media file that is distributed by subscription (paid or unpaid) over the Internet using syndication feeds, for playback on mobile devices and personal computers.

LPFM: Low-power broadcasting is the concept of broadcasting at very low power and low cost, to a small community area. These stations tend to serve small towns, or communities within large cities in the United States.

Who usese these alternative broadcast methods?
Podcast: Residential individuals, Schools Broadcasting, Church / Religious organizations, Commercial Radio
LPFM: Nonprofit Educational Organizations, State and Local governments, Private Broadcasters in all size markets

What applications can they be used for?
Podcasting's initial appeal was to allow individuals to distribute their own "radio shows," but the system quickly became used in a wide variety of other ways, including distribution of school lessons, official and unofficial audio tours of museums, conference meeting alerts and updates, and by police departments to distribute public safety messages. Religious broadcasters counter that few secular groups are equipped to fund the continuing operations of an LPFM station. In some states, the local Department of Transportation operates large networks of LPFM stations that act as Highway advisory radio stations.