Factory visit Kii Audio

Perhaps the most surprising introduction during Dutch Audio Event 2023 on October 7 and 8, 2023 was with the brand new Kii Seven speakers from Kii Audio. Almost everyone who left their busy demo room was deeply impressed by the biggest sound that Bruno Putzeys and his team managed to conjure up from those tiny cabinets. Although there was little time to talk during the show, I knew with some certainty that according to Bruno himself there was absolutely no question of ‘magic’. He believes in innovative technology and its smart application, and in both disciplines he is one of the frontrunners of the contemporary hi-fi industry. The appointment to visit the factory in Hamminkeln had already been planned before the visit to DAE, but I was extra excited because I knew that Bruno himself would also be present to provide explanations.

Say Audio

After a sun-drenched ride – which took me over a picturesque undulating piece of German countryside during the last kilometers – I parked on a small industrial estate on the outskirts of Hamminkeln, where the development and production of all Kii Audio speakers has been taking place for a number of years.

The reception by Wim Weijers, who at Kii Audio is responsible for the development of the brand on the European and American hi-fi market, was most cordial, as was the round of shaking hands with the members of the team, consisting of a remarkable number of Dutch people.

A little later, when we had taken a seat in the canteen with a cup of coffee for the first part of the visit, I asked how that came about. “We had our factory in Vaassen until 2022,” says Wim. “But there we started to outgrow ourselves a bit due to the increasing success of the Kii Three and the BXT. We then made the decision whether to rent somewhere larger, or to look for a location where we could set up a factory ourselves that offered all the space and that could be laid out the way we wanted. That opportunity presented itself here in Hamminkeln.”

“Fortunately, everyone unanimously agreed that having their own location was better than renting it again, so that’s how it was done. The fact that it meant a greater travel distance for some was no problem, we are so close as a team that it sometimes almost seems like a family. , and we felt it was valuable to maintain that.”

The atmosphere in the factory was indeed great. There were smiling faces and although the work was hard and serious, there was also time for fun. As would become apparent later during the joint lunch.

Listening to Bruno

Before that happened, I first spoke extensively with Bruno about Kii Audio and about his insights into technology, hi-fi and music. Bruno is considered one of the contemporary icons of the audio industry. With his designs, which are used by various major international hi-fi brands, he has largely contributed to the development, improvement, emancipation and ultimately the acceptance of Class-D amplifier technology within the always critical high-end audioworld. His PURIFI amplifiers, developed together with Lars Risbo, are technical highlights, which are now also used in the Kii Three, the BXT Units and the new Kii Seven. Yet he will never award himself that honorary title of hi-fi icon. That’s not false modesty, he’s simply averse to it. He is really only interested in improving the reproduction of music, because if he is anything above all, it is a music lover. But he is also one of those rare people who can explain their incredibly deep insight into technology (and especially its sense and nonsense) in such a simple way that someone with a basic understanding of the subject not only understands it, but also immediately admires it. gets an elegant simplicity from some of his discoveries and solutions.

The Kii Seven on its debut at Ascot

For example, he talks enthusiastically about the drivers used in the Kii speakers. These are good units, but not as exotic as you might expect. “We aim for the frequency curve to be approximately the same both on and off axis, and with as little distortion as possible. Then you have often come a long way. The drivers must therefore meet a few specific requirements, so we have them built especially for us by a manufacturer where it is possible to have production adjusted in the meantime if necessary.”

“The tweeter has been strictly selected because it is crucial that it provides the widest possible dispersion. This works better with our one-inch tweeter than with a 16 millimeter tweeter, which is generally better at this, and often also continues into the very highest treble. The tweeter we use performs very well in both respects.”

“While comparing different materials for the tweeter dome, we discovered more or less by chance that it was not the material used that made the difference in performance, but how deep the voice coil was placed in the air gap. Specimens in which the voice coil was positioned deeper in the air gap appeared to produce less distortion. In addition, we place copper short circuits in the tweeter drive at carefully calculated locations to prevent distortion due to hysteresis. (delay that occurs during the magnetization of ferromagnetic materials – red.) to decrease.”

“Measurements also showed that if we placed an acoustic lens in the waveguide just in front of the tweeter’s diaphragm, that lens, which also protects the diaphragm, changed the wavefront of the radiated sound in such a way that the tweeters had a dispersion of almost 180 degrees. , so that they continued to sound well balanced and undistorted even far beyond the ‘on axis’ line. This means that the cabinets need to be set up less twisted. Thanks to the kidney-shaped forward beam pattern, which we created with the help of DSP and the position of the drivers in the housing, our speakers could already be positioned closer to the rear wall, but thanks to the lens in front of the tweeter, the speakers were given an even larger sweet spot. ‘.”

“The midrange is driven by an amplifier with a very high output impedance. And because the amplifier has current feedback, we achieve a 20dB lower distortion, which you could call quite spectacular. We do things that some say don’t sound good, but our DSP engine has a higher resolution than human hearing, so it works inaudibly.”

“We also apply a very high negative feedback. That is not easy, but it offers advantages in terms of distortion. People who say that they do not apply negative feedback for the sake of sound quality probably don’t know how to get it to work properly. “But if you do know those kinds of things, you can avoid all kinds of exotic solutions. Purism is nice, but it sometimes drives up the price of high-end hi-fi quite a bit, while that is not necessary.”

The factory itself

After the interesting conversation with Bruno, CEO Chris Reichardt gave me a tour of the factory. He is an experienced music lover (and not entirely coincidentally also a musician) who made his mark in the audio industry mainly in the Pro market, including at TC Electronics, SSL and AVID, but also at the pro department of the Dutch Grimm Audio, where he met Bruno. The production lines are short and well coordinated, so that good production is achievable with a small but efficient team. A view of the warehouse rack with semi-finished cabinets – that are made at a specialized company nearby – learns that the Kii speakers and the BXT units consist of two halves of a high-quality ‘injection molding’ material that are glued together and finished in the factory before they go to the sprayer, also located nearby. There, several layers of primer and lacquer are applied over the originally caramel brown housings. In principle, any custom color is possible for the Kii Three and the matching BXT units at an additional cost, so if you want pimpel purple (there is a pair further down in the warehouse ready to be assembled and provided with software) then that is possible. For cost reasons, the new Kii Seven will only be supplied in two basic colors, white and dark gray.

It strikes me that although there are quite a few speakers in various stages of assembly on the production line, they are only Three’s and BXT’s. According to Chris, this is due to the great success of those products. About 70 percent of Kii Audio’s turnover comes from the pro-audio market. There, it is usually easier to invest in top-class products and production therefore always continues. More is expected from the Kii Seven for the consumer market, but production has yet to get underway. They are in the final testing phase, in which minor adjustments can still be made before they go into large-scale production. At Kii Audio they do not believe in beta testing with the end user. The product must be ready before it is in the store.

At Kii Audio, testing consists of a combination of measuring and listening. Bruno has developed a unique measuring method that eliminates the need to use an anechoic chamber. In the middle of the assembly hall, far enough away from all walls, there is a vertically extendable pole on which the loudspeaker is mounted, and the measurement is then done at a height of about four meters with two microphones: one close to the loudspeaker, and one at a somewhat greater distance .

The software to obtain useful measurement results is also from Bruno’s hand. The advantage of this method, besides saving the cost and physical cubic meters of an anechoic chamber, is that you can measure something very quickly in between, and then immediately make an adjustment and measure again.

After a visit to the place where all speakers are equipped with their unique software, it is time for a joint lunch. The employees and management (including, in addition to Bruno and Chris, also Bart van der Laan, who together with Bruno forms the development team, and Product Manager Tom Jansen) are at odds with each other, there are sandwiches and soup, someone gets a warmed-up piece leftover pizza from yesterday from an oven, and animated conversations are had about all kinds of things. Clearly a close-knit team with a very flat hierarchy, as Wim Weijers told me earlier.

Listen

After lunch there was an opportunity to listen. A pair of Kii Seven was set up in an attractive listening room ‘as they would be in most living rooms’. In other words, on their matching feet to the left and right next to a large television, close to the wall and not placed accurately along a ruler. Because the speakers will probably come my way sometime in early 2024 for an extensive review, I won’t tell you too much about the musical experience I had, but just like during the Dutch Audio Event, I felt my chin a few times. having to lift my lap, so to speak.

That stunning and deep bass, that enormous sound image, no matter where you sat or stood in the room, the rhythmic coherence, the speed and dynamics, the tonal accuracy without it sounding technical, and how incredibly loud it could be and still crystal clear. sounded…it was amazing again.

That’s why it was hard for me to say goodbye. I would have liked to hear a lot more and I would also have liked to talk to Bruno about a lot of things. But to avoid the evening rush hour on the way back to Eindhoven, I had to leave a little early. With a Kii t-shirt for my daughter – who fell in love with the Seven during the Dutch Audio event – and a coffee mug for myself as farewell gifts next to me on the passenger seat, it was very pleasant to reflect on an educational and, above all, very pleasant day. Things are going very well there in Hamminkeln, and I think the future looks very bright for Kii Audio.