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A chat with Martin Gateley: Where did the unusual soundkaos name originate? My day-job company for the last 20 years has been kaosevents where we design and deliver worldwide trade show exhibits for customers like the BMW/Sauber and Renault Formula One teams, Böhringer Ingelheim, Accenture and O2 and provide for them from conceptual to constructional design right through to full implementation. The connection to soundkaos thus was predestined.
How did a trade show exhibits designer cross over into loudspeakers?
I'd been fascinated by loudspeakers from a very early age. My dad loved music and large symphonies like Mahler and Bruckner and opera in particular. He had some massive Phillips boxes in a completely asymmetrical setup with one right next to his couch whilst the other one was farther away across the room. He didn't care about proper hifi imaging. He was into it purely for the music. I thus grew up around lots of great music.
I soon developed an aversion to boxes though. Their associated sound always fights with 50% of the generated sonic output which is held captive inside the box. So I experimented with various open baffles and later built various solid-wood quasi transmission-line prototypes in a friend's cabinet shop like some of what you see above. When my day job finally allowed me more time to study speaker and instrument building to a deeper extent, it soon became clear that I lacked the predictive modeling expertise necessary to avoid having to go through hundreds of time-consuming prototypes. That's how I came upon Christien Ellis.
How did you arrive at the Enviee driver?
I'd experimented with the smaller ferrite PHY-HP after I discovered Bernard Salabert through your article. At the time his health was already failing and when he passed away, future supply of his units looked too uncertain to base a new design on.
Then I came across your mention of the Armin Galm driver in one of your HighEnd Suisse show reports. I contacted Armin but as a perfect nobody in the field I didn't hear back from him for some six months. He probably thought I was a tire kicker. On a lark one day I then decided to update my hibernating soundkaos website with some renderings of what I had in mind. When I contacted Armin again I now heard back within less than an hour. He was inspired by my design outlook. We arranged to meet at a subsequent Munich HighEnd show where we hit it off. Christien who designs drivers himself measured the first two units Armin sent us. He couldn't believe how linear they were - to within 2.5dB from 60Hz - 15kHz.
Did Armin scold you for adding a Raal ribbon?
(Laughs). I don't think he was too happy. He and Joachim Gerhard insisted that this driver needed no assistance on top. But Christien confirmed my impression that we missed information above 15kHz. I'd worked with Aleksandar at Serbia's Raal Ribbon before and knew how flexible he can be to modify his drivers to small-volume OEM requirements. His ribbon tweeter thus was a must. Because I wanted no resistor on the tweeter, he modified its impedance for me so the high-pass is a simple cap.
How did you arrive at the Alpine Swiss spruce?
I'd read an article on the restoration of Stradivarius violins. And there it was - a photo of a label glued to the inside of one violin which showed the name and address of the wood supplier. It turned out that this supplier was just a few miles from where I'd grown up in Switzerland. He supplies many instrument builders and is a true resource for luthiers. Granted his quality of tone wood renders the cost of Spruce five times higher than the standard construction grade to bleed right into luxury teak turf. And then there's the very high rejection ratio once you begin to machine down the timber to discover at just about the final completion stage that there's a tiny resin inclusion on the front cover or a knot at the edge of the driver opening.
How did you find a woodworker crazy enough to even attempt this project, never mind see it through to the end?
They're actually a couple, Simon and Petra from the Wagnerei Oehrli. She programs and operates the CNC equipment. He's a young 30-something artisan who specializes as a wheelwright. But he also rebuilds 1930's carriage cars with solid wooden bodies. I can't say enough good things about them. Anyone else would have long since given up if they'd even started at all. As the next photo shows, the two clamshells with their rabbeted seam are joined with four completely concealed bolts. How to get at those bolts required great resourcefulness and Swiss ingenuity. Not only are they perfectly invisible once the two halves are joined, they don't use any plugs. To arrive at a perfectly airtight seal also requires unbelievably tight-tolerance execution. The build also relies on many specially designed and built jigs.
What about that very trick perfectly smooth constantly expanding mirror-imaged mini line?
I'm into miniaturizing wherever possible. Hence we initially started with a 25-liter enclosure. Christien soon convinced me that we'd need more volume to get proper bass extension. To remain compact he then suggested a miniature line which would flare into a short horn. His software modeling looked very promising but of course it took quite a few prototypes to arrive at the final design.
I see you lined the rear and front baffles with the same type of corrugated cardboard Sven Boenicke exploits to such good effect.
I was already familiar with this material from my trade show constructions. I generally dislike damping in loudspeakers. It kills off too much liveliness and energy. But with our parallel front/back surfaces we had too many reflections from the rear baffle back out the cone. 2.5cm of cardboard liner created so much more depth perspective in the soundstage that I was immediately sold.
The sidewalls are lined with felt and after some A/B comparisons I also lined the front baffle with a thinner layer of the cardboard. Then I remembered your Tango speakers with Frank Tchang's acoustic resonators inside. I contacted Franck and experimented with his captive silver resonator in various locations. This made an inexplicable but verifiable improvement so there's one silver resonator inside each Wave 40.