| With
the increasing complexity of broadcast production, the demands placed
upon audio operators and technical engineers have similarly increased.
An audio operator may be required to simultaneously check the main
audio sources, patch isolated router feeds for tape, and mix down
pre-production spots.
Similarly, the technical engineers must configure
the router control panels as sources become available, and this must
happen with a minimum
of interruption to tape production. Last minute changes are inevitable,
and in situations where audio router space is limited, entire setups
may require modification.
To address this, audio installations for trucks
and broadcast facilities generally require the specification of two audio systems:
the digital
audio mixer’s router, and the panel-controlled router/switcher
system. The two systems are nearly identical and differ only in the
manner in which they are controlled.
However, despite their similarities,
integrators frequently find themselves purchasing separate audio frames
from multiple vendors as single systems
seldom provide this dual functionality. Furthermore, duplication of
sources and interconnection between the two requires large numbers
of source distribution amplifiers and additional router I/O, which
raises the cost of each system, increases complexity, and limits the
capabilities of both.
Having identified the inefficiencies, Euphonix
worked toward a solution. -Its digital audio mixing systems can now fully integrate
with most
router control systems utilizing the ES-Control protocol—supported
by models from Pesa, NVISION, Pro-Bel, Sony, Grass Valley, and Utah
Scientific. The result is simpler, more efficient systems.
The SH612 MADI Router
To achieve maximum flexibility in signal routing, Euphonix consoles
utilize the SH612 MADI Router. It has a 2RU form factor that includes
redundant power supplies and boots to the last known state in five
seconds, and is designed to meet the demands of on-air operation.
The unit can be operated stand-alone, controlled directly from
a Euphonix console, or can be fitted with software allowing control
from an ES-Control-capable router controller. It provides 12 MADI
inputs and 12 MADI outputs.
In Euphonix routing systems, all studio
sources and destinations, as well as console signals, are converted
to MADI. MADI (AES10) is
a serial digital format that allows 56 digital audio signals (48kHz/24bit)
to be sent down a single 75ohm coax. The SH612 is, therefore, capable
of handling routing of up to 672 inputs into 672 outputs.
Because signals are converted to MADI, the original source
and destination format becomes transparent for the user. Additionally, the SH612
is based on a TDM backplane which allows AES/EBU pairs to be separated and reassembled
at will. |
A complete Euphonix digital audio system is lightweight, making it
ideal for trucks and remote applications. Shown here is a System
5-B digital audio mixing console on a Mobile Television Group
HDX remote truck. |
For instance, a camera mic and mono program
can be sent to the stereo AES/EBU input of a VTR by simply operating
the router panel in the tape room.
Independent control
In basic Euphonix systems, the SH612 is configured to be controlled
by the console However in broadcast facilities, where independent
console routing is required, an additional SH612-ES is deployed
and connected to the router controller. The units are identical
except for mode of control. Low-cost signal distribution
When specifying independent routing systems, it becomes necessary
to duplicate source signals across both systems. In many installations,
this requires a separate DA for each signal source. Here, the advantages
of using MADI as native audio format become clear. Because MADI
is electronically similar to SDI video, it can be run through standard
SDI distribution amps. Therefore, a multichannel front-end MADI
converter (analog-to-MADI or AES/EBU-to-MADI) can be inexpensively
distributed to both routing systems via a single SDI DA.
Considering
the numbers of signal sources in most facilities, the cost saving
can be substantial. Furthermore, this guarantees the
required sources for the facility are equally available to both the
audio mixer and panel controlled router system.
Simplified configuration
Independent router systems invariably require some level of
interconnection. As the audio operator builds isolated feeds in the console,
they frequently patch into the facility router, where the facility engineer must
associate them with video sources for tape operators and other production personnel
|
The number of audio router inputs available
is usually limited by the installation budget as each interconnection
requires purchase of a console output circuit, router input circuit,
and associated patchbay real estate.
Interconnecting
two routing systems merely requires patching one or more console MADI outputs
to router MADI inputs via coax cables. A single coax allows 56 console
signals to be placed on the router. Two or three coax cables enable the audio
operator to make available all significant console outputs (main busses and aux
busses) as well as many direct outputs. Manual patching is no longer required,
and show setups can be saved and recalled from a file.
Benefits
Digital audio console router integration provides the audio operator
and the panel-controlled router operators independent control of
every source on the system. The benefits are substantial.
Sharing
a single set of audio converters for the mixing console and mobile/facility
router can save thousands of dollars. Setups can
be stored and recalled, eliminating the need for manual patching.
In
addition, the audio operator no longer needs to patch console output busses to
the destinations. Console output busses such as
main program, aux feeds and IFBs automatically appear as sources
on the router. Engineering then has full control of all audio sources
from any router control panel.
Finally, the audio console and panel-controlled
router share a single set of audio frames — exactly half of what is often
procured. A comprehensive Euphonix digital audio system typically weighs less
than 500lbs, making the solution perfect for trucks and remote applications. |
