Tag Archives: engineering

In search of perfect sound – introducing Britain’s largest horn loudspeaker

Aleks Kolkowski, former sound artist-in-residence, remembers his first encounter with the Museum’s exponential horn.

 A long black metal tube, slightly tapered and almost 9-foot-long lay on a row of filing cabinets at Blythe House, the Science Museum’s storage facility. The object was pointed out by John Liffen, the Museum’s Curator of Communications, who guided me during a research visit of the collections in 2008. It was all that remained of a mighty horn loudspeaker that was demonstrated in the Museum during the 1930s, John explained. A demolition accident had almost totally destroyed it in 1949.

John Liffen holding the only surviving section of the Science Museum’s exponential horn. Credit: Science Museum

John Liffen holding the only surviving section of the Science Museum’s exponential horn. Credit: Science Museum

Now the tube assumed a more fascinating form, like a fossil or a dinosaur bone as we delved into audio archeology. The story of the horn, researched in great detail by John, sparked an interest in me. Four years later in 2012, on being appointed as the Museum’s first-ever sound artist-in residence, I was given a wonderful opportunity to initiate its reconstruction.

The exponential horn loudspeaker was designed in 1929 by the Museum’s curator of  ‘Electrical Communication’ R. P. G. Denman who also personally built a radio receiver to run in tandem with it. The purpose of this new sound system was to provide the public with demonstrations of the highest quality broadcast sound that was obtainable at the time. Denman saw it as setting a benchmark for audio quality, his aim was, in his words “to provide a standard by which commercial apparatus could be judged”.

The horn measured 27 feet (8.23m) in length with a cross section that curved exponentially from 1 1/16 inches (27mm) to a massive 7-foot-1-inch square (2.16m sq.) at the horn mouth. The science and theory of how horns propagate sound had only begun to emerge in the mid-1920s. It was found that a horn with an exponential shape was the most effective means of converting the sound energy from high pressure, low velocity vibrations produced at the narrow end of the horn, into low pressure, high velocity vibrations at its mouth, then radiated into the outside air. However, in order to reproduce the lowest sounding frequencies, this type of horn has to be very long with a correspondingly large opening.

An early photograph of the horn prior to its installation at the Science Museum. Published in Amateur Wireless, October 19, 1929. Credit: British Library

An early photograph of the horn prior to its installation at the Science Museum. Published in Amateur Wireless, October 19, 1929. Credit: British Library

Denman, an expert on loudspeakers, specially designed the horn in order to reproduce frequencies as low as 32Hz and up to 6kHz. This was achieved by loading it to one of the latest moving-coil driver units from the Western Electric Company (U.S.A.) namely the WE 555W, widely used in cinema sound systems of the time and now considered to be one of the greatest loudspeaker drivers ever made.

The Museum’s Western Electric 555W Compression Driver used with the Exponential Horn Loudspeaker from 1929 – 1939. Credit: Science Museum

The Museum’s Western Electric 555W Compression Driver used with the Exponential Horn Loudspeaker from 1929 – 1939. Credit: Science Museum

From 1930 until the outbreak of WWII in 1939, the apparatus was demonstrated daily in the Museum’s Radio Communication gallery. The giant horn mouth appeared through the wall above the entrance while the rest of it hung conspicuously in the adjacent Agricultural Implements gallery. It was built into the Museum’s infrastructure and may be described as being its very first sound installation.

Concerts broadcast on the BBC’s London Regional programmes provided the content for the demonstrations. Critical reactions were positive and for audiences at the time, accustomed to limited bandwidth, interference and distortion, the sound must have truly been a revelation. The Museum’s Radio gallery became a popular lunchtime destination, where sandwiches were cheerfully munched while listening to the classics or Wurlitzer cinema organ music, the audio reproduced in glorious full-range. It left an indelible impression on those who heard it, including John Liffen’s own uncle. Writing in the Audio Engineering Society Journal of April 1975, the audio experts Percy and Geoffrey L. Wilson opined that “no superior loudspeaker has to date been demonstrated in Britain”.

The horn’s mouth over the entrance to the Radio Communication gallery is shown by a museum attendant standing on a showcase! From Popular Wireless, October, 1930. Credit: British Library

The horn’s mouth over the entrance to the Radio Communication gallery is shown by a museum attendant standing on a showcase! From Popular Wireless, October, 1930. Credit: British Library

Fast-forward to 2014 and we have an opportunity to hear the horn again.

This is thanks in no small part to the magnificent efforts of the Museum’s Workshops who undertook the reconstruction project with gusto. The missing 18-feet of the horn was rebuilt over an intense 8-month period following Denman’s original specification, although fibre-glass was used in place of the original lead and tin alloy. Led by the Workshops manager Steve Long, the team has succeeded in recreating the single largest loudspeaker in Britain.

The newly reconstructed horn being tested by the author at Blythe House in August 2013. Credit: Science Museum

The newly reconstructed horn being tested by the author at Blythe House in August 2013. Credit: Science Museum

The programme for the upcoming installation is a mixture of past and present, allowing us to listen to the horn in old and new ways. Archive material from the BBC will be heard alongside recent recordings made within the Science Museum. Resonance 104.4FM will be resident in the space, broadcasting live from the Museum, while lunchtime concerts via BBC Radio 3 will mirror the original demonstrations of the 1930s. A series of events, including live music, poetry and performance will also showcase new works for the horn created by a variety of artists, writers and radio programme-makers.

The title, “In Search of Perfect Sound”, refers to Roderick Denman’s quest for audio nirvana. Our modern ears may have become accustomed to high fidelity audio and surround sound, but the exponential horn, with its extraordinary sound presence and a distinct three-dimensional effect, still holds an immersive power of its own.

I’m very proud to have played a part in giving the Denman horn a new lease of life and to have witnessed its exponential metamorphosis, from that modest-looking metal tube, cocooned above all those filing cabinets.

The Exponential Horn: In Search of Perfect Sound opens at the Media Space Studio on 20th May. An afternoon of talks and presentations about the horn and the history of radio in Britain will be held on 12th July. Speakers include John Liffen, Aleks Kolkowski, Dan Wilson and Seán Street.

Aleks Kolkowski is a sound artist, violinist and composer with a special interest in early sound recording and reproduction technology.

3D printing gadgets on wheels

Martyn Harris, cyclist and entrepreneur, looks at how 3D printing inspired him to launch a new business. See more examples of 3D Printing in our 3D: Printing the future exhibition.

My two lifelong passions are cycling and engineering. As a child I could regularly be found either riding my bike or constructing some new contraption out of lego. I started racing mountain bikes at the age of 13 and after leaving school, embarked on a four year apprenticeship to become a precision machinist.

In 2000 I joined 3TRPD, a newly formed company specializing in 3D printing. I was instantly hooked by this state-of-the-art process and have been seeking ways to introduce the technology into the bike industry ever since.

3 colour Garmin cycle mounts produced by RaceWare Direct. Image credit: RaceWare Direct

3 colour Garmin cycle mounts produced by RaceWare Direct. Image credit: RaceWare Direct

When I found myself struggling to find a sleek way of mounting my power meter to my Time Trial bike, it was the catalyst that I needed to start designing my own components using 3D printing. I opened my own company, RaceWare Direct at the beginning of 2012.

Neon Garmin mount by RaceWare Direct. Image credit: RaceWare Direct

Neon Garmin mount by RaceWare Direct. Image credit: RaceWare Direct

Having posted on cycle forums that I was making 3D printed computer mounts, the level of enthusiasm was overwhelming. Within a matter of weeks, I had dozens of potential orders and several designers who wanted to help me with new products. By the end of the year, we had a full range of products and had secured UK distribution with Saddleback, a well respected distributor of high end cycle products.

My future vision for RaceWare is for it to grow into the world leader in 3D printed cycle components.

You can see a selection of gadgets produced by RaceWare on display in the Science Museum’s 3D printing exhibition.

The Viridity racing team

From school to the racetrack

Viridity, a team of young engineers from Newstead Wood School in Orpington, Kent are taking part in our High Performance festival this weekend. This guest blog post has been written by the Viridity team. 

We are Viridity, a team of young aspiring engineers from Newstead Wood School in Orpington, Kent. We have entered into the Greenpower Challenge, a competition for students with an interest in engineering. The challenge for participating teams is to design, build and race an electric car, in competition with other schools from all over the UK.

Newstead Wood School’s Team Viridity GRT

Newstead Wood School’s Team Viridity GRT

Our team is made up of students from years 10 to 12 (ages 14 to 17) with several team members currently studying for the Engineering Diploma. The team is supported by our link engineer, Peter Fagg, a mechanical engineer from National Rail. Through his support, Peter has encouraged many students at Newstead to get involved with engineering.

Various Greenpower race categories exist, each open to different age groups. We have opted to race in the Formula 24 category, which is open to students between the ages of 11 and 16. Formula 24 races are endurance races lasting four hours and require a minimum of five drivers. We are one of only two all-girl Formula 24 teams in the UK.

Heats take place at major motorsport venues around the country, with the best teams qualifying for the national final held in October each year at the Goodwood Motor Circuit. To date our car has raced at Bedford Autodrome, Castle Combe circuit, Dunsfold Park (home of the Top Gear test track) and Goodwood Motor Circuit.

Our first year of participating in the Greenpower Challenge was in 2011. At that year’s Formula 24 national final, we finished 19th out of a field of 75 cars – 179 teams nationally – and succeeded in attaining the “best newcomer” award.

Last year, we once again qualified for the national final, but suffered a punctured tyre which set us back in the race and resulted in our team finishing 47th. Such is the nature of motorsport.

Viridity GRT at Goodwood Motor Circuit, October 2012

Viridity GRT at Goodwood Motor Circuit, October 2012

Our aim this year is to make modifications to our existing car to improve its performance. If we are able to raise sufficient funding, we also hope to build a new car for entry into the Formula 24+ category of races.

Since its inception, our team has been reliant upon obtaining the support and sponsorship of local companies. As an example, Stephen James BMW, Ruxley have provided welding services for our team as our school lacks welding facilities. Other companies, such as RP Martin Brokers have generously supported us financially. For more information on our on our project, or to offer support, please click here

Jennifer photographed with the new trophy for the Queen Elizabeth prize for engineering.

Queen Elizabeth Trophy Competition Winner Announced

This tree-like structure that symbolises the growth of engineering has been chosen as the trophy for a new global prize. The Queen Elizabeth Prize is considered to be the Nobel prize for engineering and yesterday the winner of the trophy competition was announced by Ian Blatchford, Director of the Science Museum Group.

Jennifer photographed with the new trophy for the Queen Elizabeth prize for engineering.

The prestigious award was given to Jennifer Leggett, an A Level student from Sevenoaks in Kent, who was the brains behind the winning design. Jennifer fought off tough competition from a shortlist of ten young designers, aged between 16 and 22, to win the prize and will have the unique opportunity to see her trophy presented to the winner of the Queen Elizabeth Prize at the inaugural ceremony in March 2013. Following the announcement the delighted Jennifer thanked the judges and congratulated her fellow competitors commenting on the quality and range of all the designs in the room.

3 of the 5 judges photographed with Jennifer Leggett and her trophy. From left: Ian Blatchford, Director of the Science Museum Group; Yewande Akinola, Engineer; Jennifer Leggett; Nick Serota, Director of the Tate.

The panel, who had the tough job of selecting the trophy, consisted of: Science Museum Director and Chair of judges, Ian Blatchford; architect Dame Zaha Hadid; Director of the Tate, Sir Nicholas Serota; Design Museum Director, Deyan Sudjic; and Engineer, Yewande Akinola. During the judging competitors were asked to explain the inspiration behind their design and what material would best fit their trophy but, on announcing the winner, Ian admitted that the judges had to add two additional criteria to help them whittle it down and come to a decision – whether the Queen would take pleasure from handing the prize and how the winner of the QE prize might feel when collecting their award. The winning trophy was described as “jewel-like” and was praised for its strong design which reflected the creativity, power and importance of engineering in the world today.

Reflecting on the competition Ian Blatchford said, “We set a challenge for young people to come up with an iconic trophy design that best embodies the wonder of modern engineering and reflects the merging worlds of science, art, design and engineering. Jennifer has shown real imagination and talent – all the judges were enormously impressed with her design.”

At the awards ceremony at the Science Museum’s Smith Centre, all ten of the shortlisted designers saw their trophy brought to life having had their design transformed into 3D printed prototypes by BAE Systems using the latest in Additive Layer Manufacturing technology. These replicas illustrated the intricate designs of each of the trophies which varied from Alexander Goff’s ‘Flowers and Thorns’ a towering structure of petals and sharp thorns, to Gemma Pollock’s ‘Bright Perceptions’ that centred around a double helix, and Dominic Jacklin’s ‘The Nest’ a vortex of geometric shapes which was concieved to represent the ubiquity of engineering in our lives.

The QE prize is a new £1 million global engineering prize, launched in 2012 which rewards and celebrates an individual (or up to three people) responsible for a ground-breaking innovation in engineering that has been of global benefit to humanity. The first winner of the QE prize will be announced in March 2013 and will be presented with Jennifer’s trophy by the Queen in a ceremony at Buckingham Palace.