Sound proposition

Any hi-fi buffs among our readers may well have come across MonoPulse, a loudspeaker company that is attracting rave reviews from the critics.

MonoPulse’s range of unusual looking speakers have won praise from the notoriously pedantic hi-fi press for delivering excellent sound quality at budget prices (£500–£1,400 is a snip to serious audiophiles).

So what sort of company is MonoPulse? A consortium of German PhDs perhaps, based in a lab in Bavaria. Or maybe a slick design and manufacturing operation in the US mid-West. In fact, the question should be who is MonoPulse, and the answer is Allan Hendry, retired engineering manager turned hi-fi entrepreneur.

MonoPulse’s founder and still its sole employee, Hendry assembles each pair of speakers in his workshop in the New Forest, using components sourced from a variety of suppliers, to his own exacting designs.

With more than 500 pairs sold in the UK and around the world, MonoPulse shows every sign of turning into a significant business. This is in no small part thanks to the critical acclaim lavished on Hendry’s speakers. ‘This is what real high fidelity is all about,’ cooed Hi-Fi News, while Hi-Fi Choice praised MonoPulse’s ‘vivid sound that gets you close to the music’.

But while his speakers create a big noise, Hendry remains understatement personified. ‘I suppose it is rather gratifying,’ he said, ‘but the main satisfaction is to have created what I know is a good product.’ After working in senior executive positions with the likes of BSA, Xerox, Chrysler, Plessey and Thorn EMI, MonoPulse ‘took me back to my roots’, as Hendry puts it. (The name MonoPulse relates to the radar technology with which he was involved at one stage of his career).

It soon becomes apparent that the roots Hendry is talking about are more the nuts and bolts of overcoming an honest-to-goodness engineering challenge than a devotion to any musical genre. While certainly a music lover (Freebird by Lynyrd Skynyrd sounds especially good at full blast through a MonoPulse, apparently) Hendry is in no way evangelical about it.

‘I think it was a European composer who once said that the English don’t like music, they just like the sound it makes,’ he remarked wryly. ‘I suppose I take a very purist technical approach. I asked myself what needed to be done and tried to work out how to achieve it.’ Hendry’s key inspiration for the MonoPulse project was, in fact, the reading he did to while away the time spent flying to and from the US on business during his earlier career. A book by Martin Colloms, co-founder of Monitor Audio and noted loudspeaker authority, started the chain of thought that led Hendry to found MonoPulse.

The specific technical issue to which Hendry turned his attention is the time-domain accuracy of a speaker. This relates to the way the human ear hears in nature, using fractional time differences in sound pulses to ascertain important information about a sound, such as its direction and echoes along the way. These transient pulses are mixtures of frequencies, and in nature each frequency arrives at the ear simultaneously.

Any electronic circuit that is frequency selective will delay certain frequencies, altering the synchronicity of natural sound. Hi-fi speakers and their multiple drive units of woofers and tweeters are packed with frequency-selective circuits, playing havoc with time-domain accuracy during audio reproduction.

Hendry’s solution for MonoPulse is to have just two drive units, linked by what he coyly described as ‘some special crossover electronics and clever spacing’. This, he claims, allows MonoPulse’s speakers to achieve time domain synchronism to an accuracy of three-millionth of a second, bringing a particularly pleasing fidelity to the ‘unplugged’ style of musical recordings with their many subtle nuances.

With his core technology in place, Hendry faced the small matter of actually producing speaker units to house it. ‘Loudspeaker design involves a myriad interrelated elements, from machining MDF to some very complex maths,’ he said. A MonoPulse speaker is a heavyweight piece of kit, literally so for those who take delivery of a pair. The  largest version weighs in at a hefty 28kg.

This is because Hendry wraps his units in a quarter-inch thick steel plate, ensuring that the clarity achieved by the transient matching is retained. The speakers look unconventional, and may not appeal to those who rate interior design above audio quality.

But Hendry is unapologetic about placing substance ahead of style. ‘They look as they are intended to function. Style should be there as much as possible, but not if you are going to sacrifice performance.’

As Hendry has discovered, the commercial dynamics of the hi-fi industry can seem positively bizarre to newcomers. MonoPulse has attracted praise for providing exceptional quality at an affordable cost. It soon became apparent, however, that value for money is not everyone’s cup of tea.

‘I’ve heard a lot of comments along the lines of “they’re the best things I’ve ever heard, but I was looking to spend a lot more money”,’ he said.

Hendry has travelled the length and breadth of the country over the past few  years to establish his speakers with the network of specialist hi-fi dealers who form the vital link in the chain between niche brands such as MonoPulse and the hi-fi-buying public.

‘I’ve found the industry to be a nice one to work in,’ said Hendry, extending this bonhomie — perhaps unsurprisingly, given his good reviews — to the specialist hi-fi press.

‘I was convinced to begin with that the magazines wouldn’t touch a review of a product unless you took out an advertisement with them, but in fact they are totally fair and impartial,’ he said.

Despite his unexpected second career as a hi-fi entrepreneur, Hendry has no ambitions to turn MonoPulse into a major business. His low fixed costs mean he can tick along quite comfortably, and as long as people want to buy his speakers, he will put a pair together.

If a major hi-fi company one day made him an offer for MonoPulse, he might listen. He is, however, enjoying himself. ‘I’ve certainly realised what a wonderful thing it is to be your own boss,’ he said, mainly because it gives him the ability to pursue a project ‘with nobody above me to say no’.

He is also occasionally moved by the reaction to the speakers he builds. Hendry tells the story of a son who bought a pair of MonoPulse speakers for his elderly father. ‘He sent me an e-mail telling me that his dad had listened to his entire record collection again, and that he’d never seen him looking so happy,’ recalled Hendry. ‘That made me feel pretty good.’