This project is rather different from the typical build in that it could be said to be the work of one man — the owner/operator of SounDesign, Conrad Fletcher. SounDesign provides mobile recording facilities to the broadcast audio and music industries. Fletcher has many years of experience in the audio business, starting out as an operator in theatre sound. He joined the BBC, where he managed the mobile control vehicle SCV6, recording all manner of music and speech.
Fletcher identified an opportunity in the market for a mobile recording vehicle that would offer the most efficient delivery and the best quality and could support multiple disciplines, including live TV, radio and the latest generation of delivery formats (Internet streaming, such on-demand media as CDs and CompactFlash/SmartMedia, and mobile phone downloads). The new truck, named Mobile One, also lends itself to music recording, with 24-bit/96kHz sampling from end-to-end and 40-bit processing. Designed for 5.1 mixing, the truck can also serve the expanding markets of DVD and live streaming.
For radio use, the mobile can be split into two areas: a control room and a green room/studio via a moveable acoustic wall. The rear section is multifunctional, wired for use as a studio, but can also be used for DJ'ing, Internet steaming and CD copying, as well as an edit suite of office.
With a background that includes acoustics and sound mixing, Conrad felt he had the experience to build a truck that would surpass the performance of those available from the traditional rental fleets and bring an ease of use that only a practicing sound operator could design.
Background
There are two types of mobile recording vehicles in use today: television-orientated production vehicles and audio-only recording/broadcast vehicles. The UK television world is driven by two key companies: the BBC and BSkyB. The satellite operator, BSkyB, has been broadcasting in surround for some time and recently began broadcasting sporting events in Dolby Digital 5.1, which means all the truck operators will have to make extra investments.
The market for audio-only vehicles is more diverse. As well as added facilities for TV productions (like a hub for a reality TV program), there are radio outside broadcasts, live track laying for musical events, remixing and sound for DVD releases, and emerging new trends in the music business that are presenting opportunities.
All the audio mobile recording trucks appear to have similar facilities; however, on examining their specifications, Fletcher noticed that there were a number of compromises in equipment and facilities. Most trucks are designed for music track laying and mixing vehicles, with some communications facilities added. He felt that there is more to a live broadcast than buying some extra equipment. The vehicle has to be designed with an understanding of the ergonomic requirements of a live broadcasting team.
The design specification
Mobile One was to be specifically targeted at the broadcast and new-media market. Current trucks have problems adapting to current requirements for high bit-rate multi-stem mixes, so fourth-generation digital technology would give the flexibility and audio quality that was required. By adopting an all-digital system with fiber cabling and low-power consumption, the crew can achieve quicker turnaround for higher utilization.
The truck was designed to be smaller than others of comparable quality, making it possible to record in places where the others could not fit (including many parts of Central London). Not withstanding the size, it has acoustically and ergonomically designed areas for quality monitoring unmatched in a mobile control room. No expense was spared, making the areas as pleasant to work in as possible for extended periods.
As an added bonus, the truck is built to be completely compatible with current BBC facilities, making it easy to integrate completely at large events.
The acoustics
Acoustic design for trucks can be a complex mix of compromises to meet the requirements for acoustic isolation from external noise and to give a good listening environment internally, without adding to much weight or subtracting from the internal dimensions.
Although Fletcher studied acoustics and vibration at Southampton University, the science has changed from the days when Helmholtz resonators and lattice absorbers were the favorites. Being still actively involved as an acoustician with several successful designs in colleges and universities, he was aware of new composite materials. These have been developed for such applications as the thermal and acoustic insulation of pleasure craft and specialist vehicles.
The truck is built with a floating floor to isolate the working environment from the chassis. A recycled rubber material gives high performance yet is only 10mm thick. The walls should be stiff to provide isolation from external sound but yielding to give a good absorption internally. These conflicting requirements are met with a dual skin construction separated with rockwool and an inner lining of a mineral-loaded, vinyl polymeric barrier. It can be likened to linoleum sandwiched with felt. Further inner treatment provides a dead acoustic throughout the truck, more suited to surround mixing that the live-end, dead-end favored for stereo monitoring.
The equipment
The heart of the facility is the Studer Vista 8 digital mixing system. This has 672 equivalent mono inputs, 144 mic amps as standard and with additional blocks of 48 available on request. All inputs are up to 24 bit/96kHz with full DSP on every channel with stereo to 7.1 monitoring and mixing. The truck can provide simultaneous outputs at 48kHz and multitrack at 96kHz with no format conversion, and all processing is 40-bit floating point throughout for highest signal quality.
Having worked as a sound engineer for many years with the BBC, Fletcher has used most of the popular broadcast sound desks. For the last five years, he worked on the BBC show “The Weakest Link” using a Studer D950. He liked the sound quality of the processing core and found that the desk had great build quality and reliability. In the five years of mixing the program, it never crashed — very unusual for digital desks.
When Fletcher spoke with Studer about the features he would like to see in a new desk, Studer representatives showed him the Vista. He found the concept of the totally flexible control surface much easier to operate than a conventional digital desk with a central assign surface.
Another advantage of the desk was the integral MADI fiber interfaces. With many other manufacturers, a third-party interface is needed, which opens the door for something else to go wrong.
For recording, Mobile One uses two Pyramix 24/96 systems giving up to 128 tracks plus MADI, AES and analog outputs. It also has a Sony DAT recorder, Sony and Tascam CD recorders and a Sony MD recorder.
The built-in monitoring is PMC, with MB2 active for stereo and AML1 for 5.1 monitoring. Music industry clients have their favored monitors so additional monitor feeds from the desk are wired so that other monitors can be used as required. Video monitoring includes a 1080i video confidence feed. Outboard processing includes a range of options by Lexicon, Studer, Focusrite, Urei and Neve.
The inside
The 7m chassis weighs in at 12 tonnes. As well as the usual climate control, it has low-energy mood lighting where the color can be controlled to suite the client. Two small desks behind the sound mixing position can be used by producers or for additional recording or editing equipment.
The outside
Fiber is used for the remote stage boxes, avoiding all the problems of noise and hum from a copper snake. A MADI fiber link means that two trucks can share one stagebox.
The communications required for television and radio production are integral, rather than add-ons, as is common with many music trucks. It has integrated analog telephone balance units and digital ISDN interfaces for external lines. Production communications use a Telex/Reidel digital talkback system. For new media applications, the truck has the capability for IP streaming.
Operation
Reflecting the changing times of the media business, there has been much interest in the truck for a diverse range of work, including making video for iPods and mobile phones and mixing music to sell as CDs immediately after a concert. For straight music jobs, clients bring in their own operators. But for television work, Fletcher often drives the mixer himself.
Mobile One represents a fresh approach to the increasing demands that surround sound and new media have created for video and audio production crews. And all this from an owner/operator who has designed the truck himself; something of a feat in its own right.
Technology at work
Bryston amplification
Focusrite ISA 430 Producer pack
Lexicon
960 digital reverberation system
PCM 81 and PCM 91
Neve 803065 compressors
PMC loudpeaker monitoring MB2 active and AML1 for 5.1
Merging Technology Pyramix servers at 24/96, for up to 128-track recording with MADI AES and analog outputs
Sony DAT, CD and MD recorders
Studer
Vista 8 digital mixing system with 672 equivalent mono inputs, 336 total mono outputs and 144 mic amps as standard
VSP integrated 5.1 reverberation
TASCAM CD recorders
Telex/Reidel digital talkback system
Urei 1178 compressor
Design team
Conrad Fletcher, SounDesign: conception and design
Total Audio Solutions, systems integration:
Peter Knowles
Andy Unsworth
Steven Percival: coachbuilding
Siderise: acoustic supplies
