WORDS AND MUSIC

Speaker design? Think Fink!

Advertisements

It’s one of the hi-fi industry’s best-kept secrets: the company many of the top names turn to when they need new speakers designed and engineered

‘It’s not about having the right equipment – anyone can buy that: it’s more to do with knowing the questions to ask, interpreting the answers, and constantly learning and investigating.’

Karl-Heinz Fink is sitting behind his desk in the office/meeting room of Fink Audio Consulting, housed in an anonymous building in Essen, Germany. I’ve entered down a corridor on which hang a number of guitars, and a rack of instruments sit beside his desk. As he talks, he’s absent-mindedly strumming on his latest acquisition – or it might be the most recent product of the in-house woodworking shop – and listening as he tunes it while explaining what makes the company tick.

By now you may be wondering what FAC does, and why I’m telling you all this. Well yes, it does make the odd guitar, but that’s very much a sideline, a hobby shared by several involved in the company: the main business here is the design, engineering and production of audio products, starting with speakers but now expanding into active electronics and the like.

Oh, and turntables. And guitars.

Going public
Fink Audio Consulting ‘broke cover’ at the 2016 High End show in Munich with its massive WM-3 concept loudspeakers (above), but before you dismiss it as just another of those companies showing at such shows with massively over-engineered designs unlikely ever to see production, time to think again. You see, this is probably the biggest loudspeaker company you’ve never heard of, although the chances are you will have encountered some of its products.

In fact, for some years now FAC has been the ‘go to’ consultancy for many of the world’s biggest companies when they need to launch a new speaker, or range of speakers. It works across the hi-fi, general audio, pro audio and even the automotive sectors, and can offer anything from design input to a complete ‘turnkey’ solution including design, production engineering, sourcing and quality control.

As well as its design facility, it can also offer small-scale prototyping and small-scale production in-house, and works closely with factories in China to ensure the finished products match up to the designs it develops – it even has staff permanently based in Shenzhen covering engineering and production. In addition it has strong relationships with experts in other fields, such as the industrial designer Kieron Dunk of Industrial Design Associates, with whom FAC has worked closely on many projects.

Asking the right questions
Having started out more than 20 years ago simply designing speakers, these days the company works down to the component level, designing and producing drive units using its comprehensive battery of in-house measurement tools. So it comes as quite a surprise when Fink says that, despite its expertise, the company is still learning, still investigating: as he puts it, ‘We may not know all the answers yet, but we think we know the right questions to ask, and have the tools to find the right solutions.’

It’s in the nature of a consultancy to operate behind the scenes, and not all of its clients want its involvement in their new products made public. However, of late it seems that having FAC on your team has become less of a guilty secret and more of a badge of honour, so acclaimed have many of its designs been over the years.

Indeed, Fink has co-operated with some companies for a long time: the company was in at the start of Armour Home’s Q Acoustics brand, developing all of that company’s much-lauded affordable speaker range, and now the flagship Concept 500 floorstanders, all with industrial design by Dunk; worked on designs such as the recent Boston Acoustics lines under D+M (as well as Denon and Marantz system speakers), and had a hand in Naim’s Ovator speakers as well as the drive units used in the Naim for Bentley system.

And those are merely the ones I’m allowed to mention!

That’s just scratching the surface, as was clear when I visited the company a few months ago to see how the massive WM-3 speakers were progressing, having attracted so much attention in Munich that plans were in hand to turn concept into production models.

Phone calls were flying about a problem on a soundbar speaker due on the production lines in China in days; power supplies for Bluetooth speakers were being engineered in another room; and the characteristics of a work-in-progress drive unit were being explored in a third using the company’s array of measurement systems.

All of the in-house team are music enthusiasts as well as experts in their field, and their fascination not only for their work but also many related areas of electronics and music reproduction is infectious when you tour the Essen facility.

For example, our listening session with the latest iteration of the massive WM-3 speakers, which were constantly being improved and refined, rapidly took a left turn into an exploration of the effects of various cables involved in the MacMini/Auralic/Mutec/DAC system Karl-Heinz was using as the front end of the system.

He’d already developed a prototype power supply for the computer, and was keen to try not only some cables one of us had brought, but also let us hear some wires a friend had sent him from an obscure Swiss company: ‘These aren’t so expensive, but they sound really good.’

And when we got down to the effects of a metal shell on the plug on a digital cable against the usual plastic one, it became clear not only that this company is open to the exploration of every aspect of the music reproduction chain, but also that we possibly ought to take a deep breath and get back to concentrating on what actually happens within the walls of the facility.

Back to basics
At the heart of what the company does are the fundamentals of speaker design: the behaviour of drive units and the cabinets in which they are mounted, and the interaction between the two. Central to this is the use of the Klippel R&D system, which is able to measure everything from the way a speaker cone or dome reacts to an input signal to the vibrations in the walls of a cabinet.

Fink explains that ‘Drive unit design is very different from the way it was in the past. Then people specced a shape, made it in various versions, then measured the variants and picked the best. Even back then we had a laser-scanner to make these measurements, in fact before Klippel came out with one – that was fine for measuring, but it couldn’t tell you how to solve the problems you found.

‘These days computer modelling lets you simulate materials – for example a polypropylene cone needs one shape, a metal one another – unlike in the old days where we chose a shape and then tried different materials. The choice of material isn’t the complete answer, but adjusting shape and materials works well to come up with the best solution.’

And the company is always willing to try something new: Lampos Ferekidis, FAC’s drive unit engineering expert and chief number-cruncher, used to be with driver manufacturer NXT, and so has plenty of experience in unusual shapes and materials.

He says that ‘My approach is influenced by the work I did with NXT, with BMR (Balanced Mode Radiators) technology, and the AFR (audio full range) which came before it.  The core point is that every speaker is modal,’ – ie has certain frequencies at which it performs less than optimally – ‘and you can’t change that. So you have to decide whether to push those out of bandwidth or live with them, work with them, by tweaking the modes to a different frequency range.

‘After all, what could be an advantage in a certain frequency band may not have a benefit on axis, but only appear off-axis. So the way to design is different: for example break-up’ – the point at which a driver diaphragm starts ‘misbehaving’ – ‘sounds like something negative, but isn’t if you know what you are doing with it.

‘It’s an industry fairy-tale that every mode needs to be cured by damping, but do that and you just get overlapping low-Q modes, so our way of thinking is to work with the modes. For example, many people say that polypropylene, with its high damping characteristics, is a bad material for speaker cones, but we simply design using its characteristics.

Nature’s not industry-standard
‘In our work for automotive clients, where millions of drivers have to be made, the advantages are that the cones are easier to make more consistently in huge volumes than, say, paper-based cones. After all, trees don’t grow to industry standard!’

Karl-Heinz Fink adds ‘That’s why I say I am lazy: don’t want to do the same thing many times when we can simulate and design right the first time!’

Using the Klippel system, along with his company’s experience interpreting the results it gives, has proved a major benefit for the way the Essen operation works: ‘In general, Klippel gave us low-distortion driver units. If you see drivers from companies who know how to use it, their speakers have much lower distortion than those of 15 years ago.

‘We’ve learned a lot about the stability of drivers with signal.  Break-up sounds over-dramatic, being a transition from the ideal pistonic motion to modal effects, but in fact the motion is still pistonic all the way.

‘For example, in developing tweeters for the automotive sector we had to switch from rare-earth magnets back to ferrite – it was a cost thing. We started with a design used in Castle speakers, and from there we developed Finite Element models to allow us to predict directivity, the frequency response of the driver, and how various factors affect output. That work led us to a new 28mm dome tweeter for the Q Acoustics Concept 500 (below), which radiates better off axis than the earlier 22mm design.

Always learning
‘It’s an example of how each area of work generates knowhow we can feed back into further product development. We’re always about learning why things sound a particular way, so you don’t have to go through so many iterations in the development process.
50% of our work is now automotive, and it’s getting more important these days. That means very simple crossovers, typically using just one capacitor, so we must make tweeters able to work with this, and no crossover on the woofer. So now for one major motor industry client we’re making a tweeter with very smooth integration with the woofer, just to keep things simple.’

Lampos adds that ‘Our automotive work has shown us what we measure in a car cabin is more about the acoustic power characteristics of speaker than its on-axis response, as listening in-car is off-axis. You see a lot more in the power response than in the on-axis – for example, whether a speaker will sound lean or fat or whatever. But on-axis response has been adopted due to what is like an unwritten agreement between acoustic engineers – because it’s simpler!’

Markus Strunk, who is the company’s vibration specialist, says that ‘While you can optimise drivers, the cabinet makes a major contribution, as you can hear when you do something as simple as putting a magazine on top of a speaker, or using hot-melt glue inside the corners of an enclosure.’

Using his laser scanner, he can measure cabinet vibrations, and see that ‘cabinet distortion is both apparent and audible, and that 30dB below what speaker is doing is cabinet contribution. Every time you make a change of cabinet material or change design, the speaker changes – the image, the balance, and the voicing.’

Think first, make later
Karl-Heinz explains that ‘Again we use simulations – after all, we don’t want to make many iterations of cabinet material. Marcus wrote his own programs, and now we can simulate how the cabinet will work before making a prototype.

‘The idea isn’t to construct the stiffest enclosure we can make – we decided to go for higher noise levels but consistent ones, with no peaks. For example, for the first prototypes of the Q Acoustics Concept 20, we tried to see whether we could make normal cabinets better, and discovered that the ‘figure of eight’ internal bracing used to date was bad – it was distributing noise. So instead we chose a mix of materials/sizes, and found we could make a cabinet with lower noise without all that bracing.’

Marcus adds that this led to the development of the constrained layer damping used in the speakers, using a mixture of materials and the Gelcore layer within the walls of the enclosure: ‘With the laser scanner we can measure how much energy is dissipated in the damping, and over what frequency range. The old methods were all about trial and error with accelerometers attached to the cabinet surface, but now with the laser scanning we can measure more accurately, and see the effect on sound pressure levels.’

Listening to the cabinet
And it seems the old ‘face to face, out of phase’ method enthusiasts use to cut down noise when running in speakers also has its place amongst all this hi-tech measurement equipment: Fink explains that ‘with the speakers like this, the drivers cancel out: then what you can hear is the cabinet.’

This thinking has informed every element of the cabinet design, extending to the design of the reflex port and the terminal panel: ‘If you can isolate those effects, it has a huge effect on the design. So on the Q Acoustics models we just use holes for the terminals, not a plastic panel.

‘For the new Concept 500 model this thinking has been extended to the use of a damped terminal panel made from a sandwich of MDF, steel and bitumen, thus preserving the integrity of the Dual Gelcore construction of the cabinet.’ This design, seen above, takes the technology developed for past Q Acoustics speakers, which have had two layers of material sandwiching a gel layer, and turns it into three solid layers and two layers of gel, offering even greater damping for a more inert structure.

In the meantime, Fink’s own WM-3 monster speakers are inching closer to becoming a production reality, so great was the interest shown in them on their Munich début last year. At the High End 2016 show they were demonstrated in the Marantz room (above), on the end of that company’s New Premium SA-10 SACD player and PM-10 amplifier, then in prototype form but now in production; this year Fink will have his own room at the show, and the speakers may well be called WM-4 by then, so far on have they moved from the versions demonstrated last May.

Why the Marantz connection? Well, Fink and Marantz Brand Ambassador Ken Ishiwata are both close friends and ‘partners in crime’, having worked together on a range of projects over the years. For that reason it was no surprise that, when Ishiwata decided to demonstrate the finished Premium 10 products to the world’s press back in December, they were playing through a pair of the just-announced Q Acoustics Concept 500 speakers.

So, why WM-?
The WM-3s, or WM-4s, or whatever they end up being called – I was trying to work out whether the prefix indicated a desire for world domination with these ‘Weltmeister’ speakers, but it seems it may simply be because they look like a giant Waschmaschine! – look set to sell for around €100,000 a pair. That price will include some degree of consultancy from Fink and his team on optimising the room in which they are used, while buyers may also get a personal set-up visit, and even an offer to do all the acoustic treatments if required.

Given how good the speakers already sound, those lucky enough to be able to afford them will be getting a treat. With both anechoic and controllable echoic test rooms on site in Essen, along with an excellent dedicated listening room and the facilities to prototype products in-house as well as small-scale driver manufacturing, the Fink Audio Consulting team doesn’t just create great speakers: these people also have a superb working knowledge of how their designs interact with the spaces in which they’re used.

And above all, a love of music – from making it to its recording and playback – runs through the company: taking the tour, I see guitar amps being serviced, repaired and their designs improved, and I’m given a 2014 LP by jazz musician Hans Theessink, the recording of which was sponsored and produced by Fink [Live at Jazzland, Sommelier du Son SDS 0016-1].

And down in the street-level bay where which car audio systems can be worked on (and guitar amps tested!) I find a stack of studio mixing and multitrack recording equipment. It was acquired at some point, and now is just waiting for some time to be found to bring it back into use. It’ll happen…

A while after my visit, I’m not at all surprised to see Karl-Heinz showing on Facebook his latest buy: a classic German-made Telefunken M15A tape recorder – all 50kg of it – now installed in his listening room. Used in many German broadcast stations back in the purely analogue age, you can be sure it’ll be getting plenty of use as a reference source as the company continues to develop, refine and innovate.

As Fink puts it, it’s all about knowing the right questions to ask, and having the right tools to hand, however unusual they may seem – and that’s what enables this music-fanatic company to deliver the very best solutions to its many clients.

Written by Andrew Everard

Advertisements