Roger Kessler - Piega

Piega is probably Switzerland's most famous loudspeaker manufacturer. Founded in 1986 by Leo Greiner and Kurt Scheuch, the company was initially a typical hobbyist, garage-based manufactory. Kurt concentrated on developing transducers, while Leo took on design matters and the company's finances. At some point, ribbon drivers became Piega's trademark and have remained so to this day. The cheapest models use drivers built with this technology to reproduce high frequencies, while the top-of-the-range speakers also use larger ribbon midrange panels. Because the designers allow them to play backward, the result is unique loudspeakers resembling electrostatic panels, supported by dynamic drivers only in the low frequency range. Piega's flagship designs demonstrate technical capabilities and audiophile splendor hidden under the guise of a minimalist design. During my test of the Coax 711 LTD speakers, their coaxial midrange/tweeter ribbons and aluminum enclosures fascinated me so much that I decided to find out more about them, which led to an interesting conversation with the brand's head of research and development, Roger Kessler.

Roger is one of the people who came to the audio industry from a completely different world. In this case, automotive. After obtaining an engineering degree from the Fachhochschule Technikum in Vienna and an MBA in Munich, my interviewee worked for BMW, where he was head of the car audio and loudspeaker laboratory, in charge of the architecture and integration of Bang & Olufsen systems. Then, in 2011, he moved to Schweizer Electronic, where he was involved in the design of functional safe systems (SIL). However, something must have been pulling him strongly towards audio equipment because in 2019, he joined the Piega, where an important task immediately awaited him - upgrading the TMicro series loudspeakers. These were the basis for the Ace series launched two years ago, comprising the compact Ace 30 satellite speaker, the slim Ace 50 floorstander, and the Ace Center. Their slim enclosures were designed by Stephan Hürlemann, while Roger Kessler was responsible for the technical aspect of the whole project. After the success of the Ace series, it was time for the next challenge - the expansion of the Coax series with the Coax 411, Coax 611, Coax 811, and Center 211 models. What was the development of these loudspeakers like, why are ribbon loudspeakers so important to Piega, and what will the Swiss company show us in the near future?

Some say that the place where audio equipment is made has a significant influence on its final shape. Unison Research amplifiers and Opera speakers are made in a factory in picturesque Treviso near Venice, Chord's electronics are built in a restored pumping station in East Farleigh on the Medway River. The Piega factory is located on the shores of Lake Zurich, not far from the train station, and right next door, you have a local museum, restaurant, marina, and beer garden. Is this, by any chance, the best place in the world?

Actually, I do believe that the environment in which people work influences their motivation and creativity, and thus also the quality of the products. Every place has its unique atmosphere, and I must admit, the lake is beautiful and gives us a lot of pleasure. Especially in summer, when one can go for a quick swim during your lunch break. None of us owns a yacht, but at least two of us - Mario Ballabio and Roger Schuler - are regularly out on the lake windsurfing or, more recently, wing-foiling. Then, production can sometimes come to a standstill for an hour or two. Horgen is probably not the best place, but this is where our roots are, and we all feel comfortable here. That's quite something.

Roger Kessler - Piega
Piega's flagship models are dipoles - they emit sound both forwards and backwards.

The company was founded in 1986 by Leo Greiner and Kurt Scheuch. The latter was in charge of transducer design, and in fact, there are references to ribbon units here right away. It must have been a very bold idea because the production of such speakers requires a lot of money, the right tools, and remarkable precision. Where did this come from?

The eighties were an exciting time in the field of loudspeaker manufacturing. During this time, the quality of loudspeakers developed rapidly, and it was the era of pioneers and inventors. Many prestigious companies have started their successful journey during this time. Technically, the tweeters, in particular, still had a lot of room for improvement. The idea to develop ribbon tweeters came from Kurt Scheuch's passion and interest in transducer technology. He had reflected on what it takes to make a good tweeter and how it can be constructed. He focused on ribbon tweeters. He believed that the sensational properties, such as the extremely light diaphragms - about ten times lighter than normal tweeters - and the planar drive could significantly improve music reproduction. A risk at the time, of course, but time and success has proven him right.

What role did Aldo and Mario Ballabio play in the process?

Mario and formerly Aldo are responsible for the production of the ribbons. While Piega was growing, the work tasks had to be reassigned. Anyone who has ever met Kurt knows that Kurt's creative, active, communicative nature is better suited to development and sales than precision mechanics. So just one year after the company was founded, Aldo joined the team. He made sure that Kurt's ideas could be built and implemented straight away. The congenial duo became a trio. Mario followed his father, further optimized the production process, and still manages the ribbon production today. In the meantime, Mario's daughter Alina also helps out at times - a family business, after all.

Roger Kessler - Piega
The Swiss use ribbon tweeters even in relatively inexpensive loudspeakers.

Why is the production of ribbon drivers so complicated? Could you describe step by step how it goes and what problems have to be faced at each stage?

The design and construction of ribbon tweeters are complex, combining specialized knowledge and techniques in acoustics, mechanics, and materials science. The process requires a deep understanding of acoustic phenomena and the ability to translate this knowledge into the design of the driver. The design of a ribbon tweeter normally starts with a thorough analysis of the requirements and the choice of suitable materials. This includes an understanding of the sound propagation and resonance behavior of the materials, as well as the mechanical and thermal properties of the materials used. In the construction phase, the design plans are put into practice. Prototypes are built and analyzed to optimize acoustic properties and enable series production. Manufacturability and costs must also be taken into account at this point latest... The production of ribbon tweeters itself requires high skills in precision mechanics, such as tensioning the diaphragm or soldering the conductor tracks. These steps are comparable to those of a watchmaker and require the highest precision and care. Despite the challenges, or perhaps because of them, the development and construction of ribbon tweeters have the special attraction of designing a technically unique and high-quality product that is manufactured by hand to the highest standards. Take that, nasty robot!

Ribbon drivers almost immediately became the hallmark of Piega speakers. Going up the price list, we see them in more and more advanced varieties - first as small tweeters, then as large coaxial drivers, and in flagship models as huge panels emitting sound to the rear as well. Does this technology have any limitations?

The use of ribbon drivers is a trademark of Piega. The name Piega itself is derived from the Italian word for fold, which refers to the characteristic ribbon diaphragm. In each Piega product line, ribbon technology is used in different ways. For example, the Ace Series uses AMT tweeters, the Premium Series relies on LDR ribbon tweeters, and the Coax Series uses a coaxial mid-tweeter system as a point source. The Master Series uses the Line Source System, in other words, coaxial mid-highs as line source drivers. As a result, each line has its own individual technical and visual character, which is also, and most importantly, reflected in the sound experience. If there are limits to ribbon technology, they are in the area of low bass reproduction, where the ribbons would become extremely large and, unfortunately, also extremely expensive. It is also essential for a small company to concentrate on its own strengths, so we cannot do everything we would like to. But I could imagine putting development in the headphone sector on the project agenda because ribbons in headphones can sound fantastic, and that may fit well with Piega.

Do you follow with interest the progress of competitors offering speakers with ribbon drivers, or do you think you are the best in the world at this and it is rather others who should imitate you? Just be honest...

From a technical point of view, I can understand why competitors are increasingly using ribbon drivers. Ribbons have advantages over standard cone drivers. But, regardless of my opinion of where we are positioned today compared to the competition and even though our decades of experience give us a nice head start, it is wise to continue to develop the products. The important thing is where we will be tomorrow.

Roger Kessler - Piega
The Ace was the first product series that Roger Kessler worked on.

What does ribbon driver manufacturing look like today? Over the course of these 35 years, have new materials and technical solutions emerged that have either made the process easier or allowed for a marked improvement in the performance and sound of such speakers or is it still done on virtually the same principle?

In fact, we are continuously developing ribbon technology. We use modern analysis methods with imaging procedures, such as laser vibrometry, and also work together with universities here. These methods allow us to better understand the acoustic behavior of the membranes in detail and, combined with new findings from materials technology, to take targeted measures for improvement. This can be experienced very well with the new Coax series, where the midrange diaphragm has been optimized in this way.

In all models in Piega's line-up, ribbon units are supported by dynamic woofers or mid-bass speakers of rather classical design. Do you use one of the established sub-suppliers in this regard, or are these speakers manufactured just for you?

Both. We have some drivers that are only available from us. Others have been developed in cooperation with Seas and are variants of the range. It depends very much on the area of application.

Can these two worlds - ribbons and classic dynamic loudspeakers - be combined, or will there always be some difference in technology and character to be heard here?

It is more about underlining the individual strengths of each technique and using them in a targeted way.

Roger Kessler - Piega
Roger's next task was to introduce four new models in the Coax series.

When it comes to cabinets, you are very much attached to one material - aluminum. This requires not only the right technical background to make them at all but also a thorough rethinking of the issue of fighting resonance. What's your take on this?

In fact, with metal cabinets, it is immensely important to get the resonances under control. While common materials, such as wood, have a rather benign acoustic behavior, metal is a beast and can quickly cause very unpleasant effects. Just take a metal plate and a wooden plate and knock on them with a little hammer, and it is clear what the task is. That's why all our cabinets are carefully damped. In the enclosures of the Coax series, specially developed TIM (Tension Improve Module) is also used. The original TIM placed the enclosure wall under controlled tension and thus prevented vibrations very effectively. For the 2nd Coax generation, we have also further developed the TIM modules. The sides are now not only placed under pretension but also under pull and form-fitted to the enclosure. This significantly improves the rigidity of the cabinet. All in all, metal is an enclosure material that makes high demands, but the effort is worth it because enclosures can be designed much slimmer with the same rigidity. And once you have the resonances under control, aluminum is an almost ideal material for cabinet construction due to its extremely low losses.

Aluminum cabinets give designers a lot of freedom to achieve complex shapes, but they also have their limitations, such as the finish. Have you never heard the complaint that for some interiors, such speakers are too modern? Don't you experiment with other materials and plan to introduce models built completely differently?

The goal of Piega's design is to be modern and timeless. When someone looks at a Piega loudspeaker from 20 years ago today, the reaction is often, "Yes, they already made beautiful loudspeakers back then." The same should still be true in 20 years, especially since our speakers usually stay with their owners for a very long time and may have to survive several furnishing environments. But there is no accounting for taste, and diversity gives suppliers the opportunity to find a niche, differentiate themselves, and give the brand a character with an independent design. We at Piega are currently very happy with our design and aluminum as a material. Nevertheless, we are experimenting with other materials, especially to further improve sustainability. Although our loudspeaker cabinets are very recyclable and have a very good environmental footprint due to their long lifetime, we also have our duty to do the maximum here.

Roger Kessler - Piega
Piega's coaxial drivers are a true display of precision engineering.

All these schemes, rules, and ideas, especially if we combine them with the company's location, mean one thing - high costs. Even the smallest kits in the Freckles catalog are quite expensive compared to competitors' products. Do you think they are worth paying for? That they are not only more expensive but also better?

Oops, but I see the expensive thing quite differently. Considering the sound quality, manufacturing quality, and design, our speakers are super affordable. Not only we but above that, our customers are convinced of that. Where you are right is that we do not occupy some low-price segments. Our strategy is to convince customers with a listening test that more complex technology, which causes somewhat higher costs, also clearly brings more sound quality to inspire them to the better one. This does not only apply to our top models. A good example is the Ace 30 Wireless. It is a direct competitor to the (by the way, very well-designed) KEF LS50 Wireless II. Our all-in-one system can do everything the KEF can do and more. It looks better (okay, that's a matter of taste), uses fine materials, sounds great (you may check it out yourself), and it's even less expensive than the KEF.

One of the most important novelties introduced by your company in recent years is the second generation of the Coax series. I get the impression that some models have practically not changed, but is this true? Which elements have changed even in those speakers that already existed in the first installment of the Coax series?

The Coax series is probably the most important for Piega, because it shapes the perception of the brand like no other. It stands for Swiss craftsmanship and embodies the essence of Piega with its coaxial ribbon. In contrast to the Ace Wireless, where we added new aspects to the Piega loudspeaker world, and were allowed to let off steam, so to speak, the task in revising the Coax series was to work out and emphasize the character of the loudspeaker. It is not the conceptual changes but the details that make the Coax Gen2 stand out. In fact, we have reworked every aspect, from cabinet size and shape to the damping strategy and the coax driver itself. No part has been reused from the predecessor, but it is based on the predecessor, so evolution instead of revolution. You can see and hear that.

Roger Kessler - Piega
Instead of a 'heavy' paper, metal or polypropylene diaphragm, the sound is emitted by a thin foil.

I understand that you are getting closer and closer to technical perfection, but how do all these modifications translate into sound? Is each new solution tested through listening tests? Are there situations where theoretically, something should sound better, but in listening, it turns out that it doesn't necessarily?

Unfortunately, yes, sometimes the theory is not perfect. It happens that a change does not have the effect we expect. Then we usually go out for a beer first. No, seriously, then you have to find out the reason and adjust the theoretical model. The basic principles of acoustics have been known for a long time. The problem is rather the superimposition of different, mutually influencing effects that still make loudspeaker construction an exciting challenge today. Listening is and remains the determining criterion, even during development and when assessing individual measures. As a rule, there are many small improvements that raise the sound to the next level. They seem insignificant on their own, but in effect, they add up and together bring a clear improvement that also convinces the listener.

What does the design of new models look like, and how long can it take? Is Kurt Scheuch still involved in this process?

Too long, if Alex and Manuel have their way? No, seriously, it makes sense to take one and a half to two years from the concept phase to the market launch for passive speakers. For wireless speakers, it takes another six months to a year. And no, Kurt has not left the building for good. With the new Coax generation, many ideas still come from Kurt. With others, he stood by as a competent discussion partner. Even though he is no longer with the company, we exchange ideas regularly.

A few years ago, there was a change of power in the company. The younger generation - Manuel and Alexander Greiner - came to the fore. My impression is that this was extremely important. Did it mean that the company embarked on a new path, or did it not really change much?

Succession in a family business presents a special challenge. Kurt and Leo had successfully managed Piega for over 35 years, which placed great expectations on the new managers, Alex and Manuel. They had to master the balancing act of maintaining the successful aspects while making necessary changes. They have mastered this brilliantly, bringing sales and marketing, in particular, up to date. In development, I pursue a renewal of the product development process. The goal is, as already mentioned above, to concentrate on the essentials. These are the things that have made Piega successful. Drivers, especially ribbons, cabinet, design, and sound. We will certainly not develop a streaming module or an app in-house. There are competent partners for that. In terms of organization, I can bring a lot from the automotive industry. But we are also learning a lot from software developers, so we have introduced a coworking platform and are integrating everyone involved in a joint project and communication space. I want to keep the organization small and agile so that we can concentrate on the important and beautiful things.

Roger Kessler - Piega
Piega's aluminium enclosures are stressed from the inside to eliminate resonances.

The Premium Series is offered in two varieties - wired and wireless. Which is more popular?

Very different. Across all countries and markets, they are still more or less balanced but with a clear tendency towards wireless.

Wireless solutions are very popular now, but probably not in the high-end world. Do you think this will change?

Yes, I am convinced of that. Not that standard high-end components will disappear, but there will be many customers who are no longer willing to sacrifice space for components in their living environment, no matter how beautiful and sophisticated they may be. In addition, the integration gives us the possibility to match components very precisely to each other and to achieve the desired level of quality. I am convinced that the Ace Wireless and the Premium Wireless series, for example, deliver outstanding quality compared to a combination of individual components with the same price tag.

What hi-fi system do you use at home?

Constantly changing. Mostly prototypes from the current projects. So for loudspeakers, mainly Piega. Personally, I like the homogeneity of the 411s very much these days. It's more difficult with electronics. There are excellent-sounding (digital) amplifiers. But I have a weakness for the "old masters", above all Nelson Pass and his Aleph power amplifiers, in my opinion, a very successful mixture of tube fascination and transistor accuracy. When it comes to the choice of sources, I have to admit that the digital ones from the internet have won. No turntable and certainly no CD player. The only permanent guest is an Ace 50 Wireless with Sub Medium, mainly for watching movies. But it also has everything you need for everyday music listening and is fun.

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