SoundSpiral - Technology

When complete, Sound Spiral will constitute 2 main hardware systems – an inflatable building and an audio playback rig.



The inflatable building housing the piece is 12m long, 6m wide with a ceiling height of 3 metres in the centre. The profile shape of the space is semi-circular with the building made of tubular sections. Embedded in the structure will be 48 speakers (10w rms 8ohms each). They will be arranged in groups of 6 with each group forming an arc – 3 speakers left and 3 right. 1 speaker each side will be at child head height, 1 at adult head height, and one overhead. All cabling and lighting systems will be integrated leaving a minimum of exposed cabling and limiting the opportunity for theft and/or vandalism. All hardware fittings will have fail-safe physical protection so that in the event that (for instance) an audience member decides to remove a speaker, its safety wire will come in to play and it will not be removable (or fall) without substantial intervention.

The rig powering playback will consist of a single cabinet containing computing hardware and amplification. This will connect to the speaker system by way of a single multi-way EDAC connector providing ease of use – when the rig needs to be stored away from the building it can simply be powered down, unplugged and wheeled away. There will be 2 computers and attendant conversion hardware to allow for the playback channel count of 48 discreet main channels plus several sub-channels for bass reinforcement. One of the computers will be in charge of playback and the other will be in charge of marshalling and editing audio downloaded from a web-server. Both computers will run 32-bit windows with various scripting / automation options, and the main DAW responsible for playback will be Reaper (although other software can be installed if required by a particular venue).

All-told, the structure will require a space not smaller than 14 x 8 metress and whilst intended for outdoor use, could be erected indoors if required. When used outside, the inflatable will be ballasted via its integrated water-weights which can be filled from any clean water supply. The ends of the half-tube will have integrated door flaps which can be opened and closed as required by environmental considerations. It is being designed and manufactured by Cameron Balloons – a world-leader in hot-air balloon design and deployment. As a Civil Aviation Authority certified design, build and servicing body, safety is always their watch-word and as such, the level of over-engineering in the structural aspects of the piece will be in the area of 10:1 as opposed to the more usual 3:1 found in most commercial and industrial applications. The fabrics used will be a combination of ripstop nylon (main structure) and coated, bonded polyester (similar to tarpaulins) and will conform to category B fire regulations. The design parameters are being calculated to withstand a force-6 wind. In the event of blower malfunction or vandalism (subsequent building collapse) an integrated alarm system will sound, and initial estimates suggest a worst case scenario collapse time of approximately 20 minutes. In short, every effort is being made to ensure that not only is the structure a secure and pleasant environment, but that it is safe – even under relatively severe circumstances. When the building is not in use, but still installed, it can be deflated and a supplied tarpaulin used to cover its footprint to facilitate safer storage – once installed, the piece can be inflated prior to use and deflated afterwards. The only other intervention require to the infrastructure will be plugging in the playback rig.

The custom-made flooring will be a mixture of coir matting (think doormats) and a printed surface that occupies the centre of the space – its design reflecting the circular nature of the structure itself.

For delivery, the building will deflate and pack-down to a bundle of approx 1.5m cubed, weighing approx 250kg – for transportation in a standard white-van. An appropriate trolley will be supplied so setup from delivery to playback can be performed by 2 people in approximately 2 hours.

Pre-requisites :

14x8m space such as a courtyard with water supply and drain
adequate power supply
broadband internet / network connection

Hi Q Sound

Handcrafted audio excellence.

This small audio design consultancy has worked on projects for many top european hardware names - JBL, Celestion, Wharfedale, Eminence Pure Digital - to name but a few. They are one of the "go-to" names for behind the scenes audio-design, development and testing and the results of their work can be found in a multitude of settings accross the world - from the living room to the studio, the factory floor to the concert hall.

They are the perfect compliment to Cameron balloons - a small, hi-tech, highly-skilled U.K. operation leading its field in both design and deployment of innovative high quality products.

They will be supplying SoundSpiral with hand-made amplifiers (to a bespoke design) and trendsetting loudspeakers (of their own design) originally sold as the "Videologic Sirocco range" which when debuted as Millennium products spawned many "me-too" derivatives that have now become ubiquitous - they practically invented the concept of high-performance, small form-factor loudspeakers for the desktop computer market.

In short, they are as dedicated as they are knowledgeable, and have identified the optimal balance between price and performance that will make the audio reproduction aspect of the project not just viable, but both high-quality and durable - ensuring the system will continue to function throughout its legacy, with an absolute minimum of intervention, servicing or replacement parts.



Based just outside Lincoln, the utilisation of Hi-Q’s services and expertise is congruent with the project’s dual production location, in the East Midlands (Lincoln), and the South West (Bristol). These two regions are the sources of the hardware and the voices of the SoundSpiral project, ensuring that its connection is a firm and solid one, in each location.

Cameron Balloons

My reasons for selecting Cameron Balloons to collaboratively design and manufacture/ fabricate the inflatable structure which will form the infrastructural basis of SoundSpiral are as follows:

(1) The structure must be capable of withstanding constant and possibly heavy through-flow of the public, without any recourse to footfall management. In other words people must be able to move freely through the structure without any need for pre-entry briefing. Having visited another creative inflatable space I noted that the need to waylay visitors to explain to them how to behave safely within the space would not be appropriate for the showing of SoundSpiral.

(2) Safety is paramount for this project. There are several manufacturers who do hold good safety records but, based on the research I’ve done, none of them is building to the extremely high specifications that Cameron’s use and I feel the high spec’ is not only justifiable but necessary for this structure, of which I shall be making prolonged and exacting demands, in terms of the hardware it must contain and the working life I intend it to have.

(3) Cameron’s is the only manufacturer I’ve found with a world-beating tech’ spec’ track record and the technical know-how to pull off the toughness and detail required for SoundSpiral.

Cameron Balloons have decades of experience of designing and constructing structures capable of holding high value hardware safely, for extended periods. They are primarily an engineering company, working in fabric rather than heavier materials. They have engineers on the staff, putting technical specification at the very top of the agenda, as well as artists, upholsterers and textile specialists.



Cameron’s hold design, production and maintenance approvals granted by the European Aviation Safety Agency (EASA). These are referenced EASA.21J.140, UK.21G.2166, UK.MF.0041 and UK.MG.0448. They are subjected to annual audits to ensure that their internal procedures meet the required standards and are adhered to for all work carried out, thus ensuring that all creative endeavour rests on the most solid technical engineering basis possible. Cameron’s structures are fit for purpose, with built-in over-engineering up to 500 % of minimum requirements. Their safety procedures are water-tight. Their structures trouble free and hardwearing, with built-in contingency procedures. They are capable of producing highly innovative and creative designs, but they are not dreamers; they are nuts and bolts experts, and also they are nice people.

Cameron’s creative projects have included a 60 metre inflated character, shown in Japan, standing upright, thanks to Cameron’s design; a Dome commissioned by VW as a static Visitor Attraction centre piece where concerts are also given; a large inflated dome for Green Peace, shown at the Glastonbury Festival; a flying UFO inflatable, commissioned by Dream Engine, to show in the air above festivals; numerous high-spec’ structures built, as SoundSpiral will be, to military specification.

The design for the structure includes the following features:

(1) Facility to be let down at night, whilst keeping the playback hardware safe, in place, protected and ready for easy reinflation in the morning. This will make a huge difference to the ask of venues and those tasked with overseeing the structure, whilst showing.

(2) Construction from two fabrics: Pvc coated polyester (500G per square metre) will be used for the flooring and water ballast bags, combining a premium look and feel with maximum handleability whilst keeping robustness central. These parts of the structure will be welded together, for utmost toughness. For the upper portions of the structure Polyurethane coated nylon (250/300 G per square metre) will be used. This fabric, being lighter, will be more translucent and handlable, maximising the movability of the structure. This fabric will be hand sewn, by Cameron’s team of in-house specialists.

(3) Water ballast. This solution combines utmost safety with convenience and flexibility. Staking the structure would rule out exhibition on any standing other than open ground. Bolting down would only work on concrete standing with the facility to introduce anchor points. Sandbags would have to be carried, in large numbers, along with the entire installation. Water ballast bags can been filled and emptied on-site, and are appropriate for use on any standing, thus creating a cover-all solution with safety and usability at its core.

(4) The blowers, proposed for the structure will be reduced noise, with inputs via spiral-wound ducting, to further reduce noise. They can also be located remotely, if necessary. They will have sufficient capacity to incorporate failsafes and clear procedures for clearing the structure, in the event of emergency deflation.

(5) Modular construction, so that, IF the structure were to develop a leak, for instance due to malicious attack, deflation would be slowed, to facilitate easy and safe evacuation of the public. Additionally, the blower capacity (either one blower with a second ready to trip in or two blowers running below flat-out) will ensure that any deflation can be slowed down further. Air loss alarms will alert invigilators to any loss of pressure.

(6) The speakers through which the audio will playback will be securely embedded in the structure, in tailored insets, where tough Velcro will be the main attachment, backed up by safety cords which would only allow the speakers to drop a few inches, if they did leave the structure. This solution combines public safety with attractiveness. The exact design of these speakers insets will be finalised following trials by Cameron’s, to ensure that the tendency of the inflatable structure to ‘spit out’ the speakers can be counteracted from the design onwards.

(7) Class B fire retardant fabrics. This is Marquee specification: melting, letting fumes out, without causing internal smother or allowing toxic dripping. This solution combines maximum safety with usability and is perfectly acceptable for public access.

(8) The entire structure, when deflated, will be moved around on a trolley, specified by Cameron’s, following weight tests.

(9) The audio control hardware will be located on another trolley, which can stand adjacent to the main structure, covered by a small self-contained tent.

(10) The structure will safely withstand winds up to gale-force, without moving or otherwise posing a danger to the public. If windspeeds become so strong that the structure is rendered unsafe then the solution is to simply evacuate and close the end doors. However, the military specification of SoundSpiral means it is very unlikely to ever encounter wind conditions it cannot withstand safely.

N.B.: The selection of Cameron Balloons, as the manufacturer and technical designer of SoundSpiral was made at SoundSpiral’s inception, following extensive research and tendering among sector leaders. Camerons were selected, bearing in mind that an inflatable structure caused a public casualty, within the last couple of years, because their quote combined aesthetic excellence with outstanding risk and safety awareness. Their quotation was not the lowest obtained, but it was the only one found to be of sufficient quality for the SoundSpiral project. In short, the selection of Camerons, to make the SoundSpiral, has been all about public safety and superlative design, from the very beginning.