A former Rover engineer has left the turmoil of Longbridge behind and designed a new style of speaker which is more curvy Porsche than boxy Volvo – and offers better sound quality than conventional cabinets.
Aonghus O’heocha left Rover and set up on his own in May last year after spotting a gap in the speaker market. With demand for home cinema and surround-sound systems growing, he set about creating a flexible speaker system for use with these, computers and hi-fis.
O’heocha Design claims its values include `out-of-the-ordinary styling’ and the D2 Series, on sale for £1,100 per pair, could hardly be accused of being conventional. With matching aluminium and steel tripod, the spherical speakers look more like visitors from Mars than living-room appliances.
Not surprisingly O’heocha slams most speakers for being `boring and boxy’. But it was function, not aesthetics, that drove the initial design of the product. `It was a question of using my engineering skills to produce the ideal speaker enclosure shape, which is spherical not boxy, to produce a very flat frequency response,’ he says.
According to O’heocha, box speakers produce about 2-3 decibels of distortion across the frequency range, whereas this distortion is limited to a range of -0.5 to 0.5 in spherical speakers, providing a much cleaner, more detailed sound.
The curved surface eliminates the standing waves which occur when sound waves are reflected between the two parallel walls of a box speaker until the energy in the wave is dissipated. This process can harm sound quality by introducing an effect known as `boxy colouration’ into the audio signal when standing waves are reflected back to the driver cone.
The working parts of the D2 are heavily damped and lined with medium-density polymers to prevent vibrations caused by movement from disrupting the music.
The bass driver and reflex port are positioned in the centre of the sphere to give a flat frequency response. And a 28mm double neodymium tweeter is placed on top of the sphere for a wide dispersion of high-frequency signals.
During normal use the speaker is capable of handling 130W of power, while for short periods it can cope with blasts of up to 1kW.
The rigid external shell is made from aluminium and lined with ethyl vinyl acetate to absorb resonance, increase mass and contribute to the speaker’s impact strength.
O’heocha developed a metal spinning process to produce the speaker cabinet, which he says is more time and energy efficient. `It was quite difficult to make,’ he says. `You take a metal disc, mount it over a lathe and force it over a special tool.’
Using this process a one-piece cabinet is produced, which O’heocha believes is stronger and has better sonic performance than traditional speakers.
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