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Kaiser Acoustics

Manufacturer: Kaiser GmbH
Price (in Poland): 16 000 euro/pair

Hans-Jürgen Kaiser
Hanzing 1 | 94107 Untergriesbach | Germany


Provided courtesy of: JPLAY

his type of companies is usually referred to as a "family firm." In the picture further below to the right you can see four members of the Kaiser family: Hans Kaiser (right) with his sons Florian, Martin and Hans-Jürgen (from left to right). Hans and Hans-Jürgen are managing directors of Kaiser GmbH.
The company is located in a charming location near the Alpine town of Untergriesbach in Bavaria, in south-east Germany. It was founded in 1948 as a wood-based engineering company. Soon, it began to offer complete solutions in the field of room acoustics. When you look at the next picture, showing the company's showroom, you will see that they had to be good at it. The room looks great, professional and pretty.
If I remember correctly, the company first drew my attention about three years ago, at the High End show in Munich. Actually, not the company as such, rather than one of the largest Duelund coils and capacitors that I'd seen in my life. They turned out to be the components of external crossover networks used in the Kawero! Classic speakers. The crossovers were as big as powerful monoblock amplifiers.

A great attention to detail can be seen in every part of speaker designs from this manufacturer. The Chiara is the smallest standmount speaker in the three-model Kaiser Kawero! range. Kaiser Acoustics technical director is Rainer Weber, who is based in the city of Regensburg, located 140 km from Untergriesbach, and who holds a senior position as an acoustical engineer in Continental AG, an automotive component specialist. This gives him access to all kinds of new interesting technologies and materials.
The Chiara’s cabinet is made of the same type of material that was previously used, for example, in Clearaudio turntables. It is a high density plywood modified under high temperature and pressure, with rigidity equal to that of steel. Hence, its name: Panzerholz (‘tankwood’). In order to suppress vibration, the cabinet is made of a tankwood, rubber and glass fiber sandwich. The enclosure avoids any parallel surfaces and its shape somewhat resembles a diamond cut. The stand is integral with the speaker and is made of the same material. There are different types of finish available, including a carbon fiber front panel. Wooden components are finished with a fantastic looking high gloss Italian lacquer (10 layers).

On a closer look, the rear edge of the stand base features beautiful speaker terminals that I have seen before in the Soulution 530 amplifier (see my review HERE). The Chiara employs design solutions that are older than myself, but applied in a modern way. It might seem that what we have here is a three-way design, with two drivers on the front baffle and a third one in the rear. Actually, a large diaphragm on the back panel is a passive radiator, without a magnet, used in place of a classic reflex port. Its presence makes the Chiara similar, in terms of design concept, to one of the icons of loudspeaker technology, the Sonus Faber Extrema. Unlike the latter, however, the treble is handled here by a different type of transducer, Dr. Heil’s AMT (Air Motion Transformer), invented 40 years ago. I have discussed it in my review of the GoldenEar Triton, but let me do a quick recap.

Air Motion Transformer

The AMT transducer was invented in the early 1970s by Dr. Oscar Heil, a German electrical engineer, and is now used by many companies under various proprietary names:
  • Precide (Switzerland) - Air Velocity Transformer (AVT)
  • ELAC (Germany) - JET
  • ADAM (Germany) - Accelerating Ribbon Technology (ART)
  • EmotivaPro (USA) - Airmotiv
  • MartinLogan (USA) - Folded Motion Tweeter (FMT)
  • Burmester (Germany), which uses the name of Air Motion Transformer
  • GoldenEar (USA) calls it High-Velocity Folded Ribbon Tweeter HVFR
  • German Mundorf uses the original name AMT.
Transducers of this type for the first time applied in their columns American company ESS (Electrostatic Sound) already in the 1972. Actually, it needs to be mentioned that before he was even Peter Walker (of QUAD fame), who in the years 1952-1953 developed the Quad Corner Ribbon Loudspeaker, with a horn-loaded ribbon folded transducer.
Often called, erroneously, “ribbon” tweeters they are actually "Folded Ribbon" as the diaphragm is not flat. The air is compressed and expanded in something that resembles, from the outside, accordion bellows. A small, 25 mm tweeter has an active surface equivalent to that of an 8-inch transducer. And it boasts a faster response than a small dome. The downside is the high cost and the need of a careful, professional application.
Although currently almost every manufacturer, except ADAM, uses it as a tweeter, Dr. Heil also developed a mid-woofer version of the driver.

The speaker reviewed today is full of interesting design concepts and ideas. While it may not alter the course of audio history, it makes intelligent use of what has already been invented by big players in the industry. On top of that, it adds perfect workmanship and fantastic looks. No idea can substitute that.

Albums auditioned during this review

  • Billie Holiday, Billie Holiday, Clef/UMG Recordings UCCV-9470, „David Stone Martin 10 inch Collector’s Selection”, CD (1954/2013).
  • Charlie Parker & Dizzy Gillespie,Bird & Diz, Mercury/UMG Recordings UCCV-9466, „David Stone Martin 10 inch Collector’s Selection”, CD (1952/2013).
  • Diary of Dreams, Elegies in Darkness, Accession Records A137, “Limited Edition” CD (2014);
  • Diary of Dreams, Panik Manifesto, Accession Records EFA 23452-2, CD (2002).
  • Diary of Dreams, The Anatomy of Silence, Accession Records, A 132, CD (2012).
  • Frank Sinatra, Sinatra Sings Gershwin, Columbia/Legacy/Sony Music Entertainment 507878 2, CD (2003).
  • Frank Sinatra, Where Are You?, Capitol Records/Mobile Fidelity UDSACD 2109, “Special Limited Edition No. 261”, SACD/CD (1957/2013).
  • J.S. Bach, The Complete Golberg Variations 1955 & 1981, wyk. Glen Gould, Sony Classical/Legacy S3K 87703, 3 x CD (1956, 1982/2002).
  • Kenny Burrell, Soul Call, Prestige/JVC JVCXR-0210-2, XRCD2 (1964/?).
  • Kraftwerk, Live on Radio Bremen, Philips 2561971, “Bootleg”, CD (2006).
  • Niccolò Paganini, 24 Caprices for solo violin. Op.1, wyk. Mayuko Kamo, BMG Japan BVCC 40003, “RCA Red Seal”, CD (2009/2012).
  • Patrick Noland, Piano Gathering Light, Naim naimcd011, CD (1994).
  • Waylon Jennings, Waylon Jennings, Stockfisch SFR 357.4801.2, “Analog Pearls Vol. 1”, SACD/CD (2014).
Japanese issues available at

Digital technology was in its infancy in 1981, when Gould recorded Bach’s Goldberg Variations for a second time. The claim that digital recordings were on the fine edge of fidelity, with a completely flat range from 20Hz to 20K Hz, was technically true, but the recorders were using digital circuits rather than the ever-improving conversion chips that we use today. As a result, digital technology delivered a very clean, quiet sound – free of tape hiss and LP surface noise – but it was also brittle, compressed, and not quite “musical” to many listeners’ ears. But digital technology was new in 1981 so everyone wanted to use it – including Glenn Gould, a known technology aficionado. […]
While Steve Berkowitz, Tim Page, Richard King, Andreas Meyer and I were auditioning the session tapes for this package – listening to out-takes that could be interesting to include – we used the analogue reels for their easy handling. Soon after this process began it became apparent to us all – the analogue tapes sounded far superior to the digital tapes. […] And we knew that we had to use these never-before-heard analogue tapes for this special release.

LOUISE DE LA FUENTE, From digital to analogue: technical notes on the 1981 Goldberg Recording [in:] J.S. Bach, The Complete Golberg Variations 1955 & 1981, Glen Gould (piano), Sony Classical/Legacy S3K 87703, 3 x CD (1956, 1982/2002).

The world of audio is full of such twists and turns. Each new technology, idea or design solution seems to be the answer to its ills. Many of them are a step in the right direction. But it is usually just the first step and it often takes years to bring the idea to a level where its advantages outweigh the drawbacks. In the case of the Compact Disc format, it has been about thirty years. However, there are solutions that still have something unique to offer, for example paper cones in midrange drivers and tweeters, or AMT transducers. It has taken the latter forty years to reach the position they are in today. Or, actually, not them but the people who had to learn how to manufacture them and to find the right application for them. I have referred above to the story of the famous Gould’s recording and his second take on Bach’s masterpiece with a clear thought in mind: I had not heard such piano in a long time. So well recorded piano, that is. I do not know why the three-disc release from 2002 is the only one where we can hear Gould’s recording from 1981 transferred from an analog tape, so called "backup tape," which is usually made to be used "just in case." All other releases use a PCM digital tape, including the Glass CD version that costs around $3,000, and which won our hearts during the auditions at the Krakow Sonic Society (see HERE). Hence, imagine this: the Chiara showed the piano on Gould’s CD made from the analog tape in such a way that made my hair stand on end.

Compared to Gould, Diary of Dreams seems to be not just poles apart but distant arms of a spiral galaxy. Both in terms of composition, music, performance as well as recording. I will not dispute that as it would be pointless. All I want to say is that in the vast musical universe there is also room for this kind of music. As long as it fulfills its role, i.e. evokes emotions, effects changes in us or even simply makes us feel good, its existence is justified.
In my eclectic record collection there is therefore place both for Gould and Diary of Dreams. The German members of DoD record their albums quite well, although they use a rather high compression, focusing more on rhythm and beat rather than on rich tonality of vocals (for more information on the difference between a collection and a set see HERE).

That was true until their album The Anatomy of Silence. Being a kind of interlude between regular band releases, it included acoustic versions of songs selected by the band leader, Adrian Hates. I knew that a different approach to the recording, giving rid of the ubiquitous deep compression and the need to emphasize the vocals resulted in a much higher quality sound. This experience translated into tangible results during the recording of the next "regular" DoD album, Elegies in Darkness. Here, too, the vocals, although not as brilliant as on The Anatomy…, were good enough to justify talking about a new Hates’s approach to sound quality.
When I played one, then another and another track from the acoustic album, I had a flashback of what I’d experienced with Gould: shivers up and down my spine and enchantment.

The secret of speakers from Kaiser Acoustics is a perfect integration of all three transducers. You do not hear not only the place where the paper dynamic driver is crossed over with the AMT tweeter, but it also difficult to identify the range handled by the passive radiator. The Chiara sounds like a single extremely resolving full range driver.
In the first reaction, we find the sound to be delicate, well groomed and refined. Until something in the recording does not disrupt this perspective. Like Hates’s multi-tracked vocals on the acoustic Diary of Dreams. I'd never heard them played back so well, in terms of tonality, and yet so well differentiated. My Harbeth M40.1, so far a champion in this area, showed them slightly more homogeneous.
I think that this is largely the result of excellent AMT driver. I have already pointed out its qualities in my review of the affordable GoldenEar Triton Seven that uses a modified version of the driver. They include smoothness, resolution and differentiation. The lack of any aggression and roughness is simply shocking. The transition from a classic tweeter to the AMT driver evokes in the listener the impression of a smoothed out sound. But when they listen to the piano, with its unprecedented attack and sonorousness, or to a recording that usually somewhat offended (compensated by the music itself, but still), like DoD recordings, then this impression disappears, replaced by calmness.
The AMT is not absolutely transparent, as there is simply no such driver. It is not capable of building up so-blooded and solid, three-dimensional bodies as the best silk domes, for example Dynaudio in the Sonus faber Electa Amator II. It is closer in this respect to beryllium and ceramic domes. They are all forgiving rather than (overly) discerning.

It's easier to discern Chiara’s own character when we talk about the lowest range. The passive radiator is characterized (for me) by slightly soft sound, a nice extension, but without focusing sound and drawing big plans. And it is the bass that is the foundation of a good soundstage; it creates the size of phantom images and their volume.
The driver used in the Chiara does not stray too far from this description. It is thanks to it that the German speaker sounds so "friendly" and so fantastically "inviting." In contrast to many other solutions, for example those used in the said Tritons, it differs in its dynamic capabilities. Seemingly quiet and performing best in the reproduction of the human voice, the Kawero! can sound powerful, dynamic and with "oomph."
Bass extension is not especially deep, after all it is not a big enclosure. But when you play something that requires low bass, high dynamics and good differentiation, like Diary of Dreams Panik Manifesto or Kraftwerk’s concert from 1971, you will "see" a grand-scale presentation, with big sound and depth.
There is no getting away from Miracles, however, and they differ from large loudspeakers with their dynamics where the lowest sounds play an important role. Even on Gould, in the passages that are played harder by the pianist, and his left hand is louder, the dynamics was slightly flattened, and the sound was not as dazzling as to where the band was narrower, for example Japanese reissues of recordings originally released on 10-inch discs.

A common audio stereotype is that standmount speakers are excellent in building up the soundstage and "disappearing" from the room. There is a grain of truth to it, as to every stereotype, but no more than that. As a matter of fact, I heard more floorstanders with great imaging than stand mount speakers. It is better to build the stage and arrange the columns with a large front panel (wide baffle) than narrow. And, as I’ve said, the key to a good soundstage is bass coherence and extension. This is where monitors are lacking.
The Chiaras could, however, be an example of that on anything but the stereotype is built. Just as the Raidho D1 I once auditioned, which sport an equally well executed bass, and the Sonus Electa II referred to earlier, so too the German speakers build up a very large and expansive stage (see HERE). The D1 showed it in a more focused way, with further layering. The Chiaras are equally good in focusing the on-axis elements, like human voices, but they bring in the musical events to our room, in which they resemble other excellent monitors, the JBL Studio Monitor 4429. The Harbeths and the Raidho, for example, move the listener to another musical space. It's hard to say which creation (because a creation, not a re-creation) is more appropriate. I enjoy both of them, as long as they are so well executed as in all the above mentioned speakers.


I am not sure if it came out that way, but the |Chiara is one of those speakers that make a great impression. Its ability to differentiate while maintaining a dense and smooth sound is top notch. Great dynamics, as long as recordings are not based on the lowest bass, beautiful treble and dense midrange are something that we expect of good monitors and that we get here. The Raidho D1 from a similar, very high price range are on the same shelf, quality-wise. Yet they sound different. Their bass extension is deeper and is coherent down to the very bottom end. The Chiara rolls it off slightly; the deeper, the more. On the other hand, the German speaker better differentiates the midrange and more accurately show the tonal shades in the treble. It also nicer conveys the shades of dynamics. The difference is not large, but it gives you the ability to decide what is more important to you. An important characteristic of the speakers under review is that they require a powerful amplifier with high current output capability to maintain the dynamics and frequency range extension.
This is one of those speakers that I would be happy to keep. Maybe not to replace the Harbeth M40.1, because they do not have the frequency range and dynamic of the latter (although they do have the smoothness and depth; maybe even better), but as something next to them. Hence, I am incredibly curious what would the flagship Classic model sound like, with external crossovers. If it added to the Chiara everything that is lacking in the latter, it could become my reference speaker.

A few simple words from…
RAINER WEBER, technical director

I am head of the NVH department and Senior Technical Expert at Continental AG. I studied physics and electronics. I am 46 years, married with one child. I built my first pair of speakers when I was 11. Keiser GmbH currently employs 21 employees, and its CEO, Hans Jürgen Kaiser, belongs to the third generation of people working there. We have three powerful CNC machines: one 5 axis, two 4.5 axis and one 3-axis. Thanks to our machine park and the workers we are at present one of the most advanced wood-based engineering companies in the whole of Germany.

In conventional designs, dynamic intermodulation back into the driver motors becomes a significant factor smearing the time domain, and RFI intermodulation with the complex signal severely modifies the tonal content of the output.
To prevent this, the enclosure is built from special material called Panzerholz in German ("tankwood"). It is well known for its extremely high density (it sinks in water), high strength (it is used in place of metal) and for being bulletproof. Measurements show that Panzerholz belongs to the group of materials that have the best vibration damping characteristics. Moreover, the value of Young’s modulus is different in each of the three dimensions, while the density is the same. This gives it a surprising property - the velocity of sound propagation in Panzerholz varies in each direction.

Another trick I use a stand permanently attached to the speaker. The Chiara is doing substantial work when the music is in full flight, draining signal-related ‘real time’ energy down into the stand labyrinths from both the drivers and the crossover, and the EMI treatment is killing the signal/RFI intermodulation products too. We installed Panzerholz-made bracing in the labyrinth, thus damping vibration.
Ultimately, it’s about achieving good behavior in the time domain, fighting against intermodulation products. If we made exactly the same speaker with MDF and without all the anti-vibration components from Vertex AQ, we would certainly have the same frequency response, but the sound would collapse as energy levels build. This technology is so revolutionary that at first it’s not obvious why it’s there. But it’s the major key to a big sound out of a small speaker (less harshness, more clarity, improved dynamic range). This is really why the speaker behaves like it does – time domain coherence and the ability to keep a stable and detached image (phase accuracy), as energy levels increase, is the differentiator here.

A two-way speaker design can look differently. This may be a classic two-driver loudspeaker in a sealed enclosure, like the LS3/5A (in KEF’s version reviewed HERE) or two-driver ported design, either stand mount or floorstanding, and others. The inexpensive Triton Seven from GoldenEar Technology, with two mid-woofers, a tweeter and two passive radiators, is one of the more complex two-way designs currently available on the market.
The Chiara is somewhere "in between", with a tweeter, midwoofer and passive radiator. The latter is mounted to the rear panel, exactly the same way as in the legendary Sonus faber Extrema speaker. The German speaker, however, employs a completely different tweeter, the transmitter AMT Heil, in a Mundorf version, with a large, rigid front panel. The 150 mm midbass driver comes from the Scan-Speak Illuminator series, and features a sandwich paper and carbon fiber cone. It is a great driver with a diecast basket and massive magnet. The ABR (Auxiliary Bass Radiator) is custom made for Kaiser Acoustics.
The crossover is a good example of how attention to detail translates into the end result. This expensive approach, but in the high-end otherwise you cannot. It sports expensive CAST Cu passive components from Duelund. They are assembled point-to-point, with no circuit board. The individual components are fitted to the enclosure and secured from vibration. The cabinet is made of the Panzerholz plywood sandwiched with rubber and fiberglass. There are no parallel surfaces throughout, and the enclosure has an internal advanced vibration control system. The speakers are integral with the stands that do not use spikes, but soft pads instead. A single pair of binding posts is mounted to the stand base, just above the floor. Sheer perfection.

Specification (according to the manufacturer)

Frequency response: 40 Hz – 30 kHz (± 3dB)
Sensitivity: 87 dB/2.83 V
Impedance: 4 Ω
Crossover point: 3100 Hz
Recommended amplifier output: 150 W
Dimensions: W 295 mm x D 470 mm x H 1160 mm
Weight: 34 kg/each



- Turntable: AVID HIFI Acutus SP [Custom Version]
- Cartridges: Miyajima Laboratory KANSUI, review HERE | Miyajima Laboratory SHILABE, review HERE | Miyajima Laboratory ZERO (mono) | Denon DL-103SA, review HERE
- Phono stage: RCM Audio Sensor Prelude IC, review HERE
- Compact Disc Player: Ancient Audio AIR V-edition, review HERE
- Multiformat Player: Cambridge Audio Azur 752BD
- Line Preamplifier: Polaris III [Custom Version] + AC Regenerator, regular version review (in Polish) HERE
- Power amplifier: Soulution 710
- Integrated Amplifier: Leben CS300XS Custom Version, review HERE
- Stand mount Loudspeakers: Harbeth M40.1 Domestic, review HERE
- Stands for Harbeths: Acoustic Revive Custom Series Loudspeaker Stands
- Real-Sound Processor: SPEC RSP-101/GL
- Integrated Amplifier/Headphone amplifier: Leben CS300XS Custom Version, review HERE
- Headphones: HIFIMAN HE-6, review HERE | HIFIMAN HE-500, review HERE | HIFIMAN HE-300, review HERE | Sennheiser HD800 | AKG K701, review (in Polish) HERE | Ultrasone PROLine 2500, Beyerdynamic DT-990 Pro, version 600 - reviews (in Polish): HERE, HERE, HERE
- Headphone Stands: Klutz Design CanCans (x 3), review (in Polish) HERE
- Headphone Cables: Entreq Konstantin 2010/Sennheiser HD800/HIFIMAN HE-500, review HERE
System I
- Interconnects: Acrolink Mexcel 7N-DA6300, review HERE | preamplifier-power amplifier: Acrolink 8N-A2080III Evo, review HERE
- Loudspeaker Cables: Tara Labs Omega Onyx, review (in Polish) HERE
System II
- Interconnects: Acoustic Revive RCA-1.0PA | XLR-1.0PA II
- Loudspeaker Cables: Acoustic Revive SPC-PA
System I
- Power Cables: Acrolink Mexcel 7N-PC9300, all system, review HERE
- Power Distributor: Acoustic Revive RTP-4eu Ultimate, review HERE
- Power Line: fuse – power cable Oyaide Tunami Nigo (6m) – wall sockets 3 x Furutech FT-SWS (R)
System II
- Power Cables: Harmonix X-DC350M2R Improved-Version, review (in Polish) HERE | Oyaide GPX-R (x 4 ), review HERE
- Power Distributor: Oyaide MTS-4e, review HERE
- Portable Player: HIFIMAN HM-801
- USB Cables: Acoustic Revive USB-1.0SP (1 m) | Acoustic Revive USB-5.0PL (5 m), review HERE
- LAN Cables: Acoustic Revive LAN-1.0 PA (kable ) | RLI-1 (filtry), review HERE
- Router: Liksys WAG320N
- NAS: Synology DS410j/8 TB
- Stolik: SolidBase IV Custom, read HERE/all system
- Anti-vibration Platforms: Acoustic Revive RAF-48H, review HERE/digital sources | Pro Audio Bono [Custom Version]/headphone amplifier/integrated amplifier, review HERE | Acoustic Revive RST-38H/loudspeakers under review/stands for loudspeakers under review
- Anti-vibration Feets: Franc Audio Accessories Ceramic Disc/ CD Player/Ayon Polaris II Power Supply /products under review, review HERE | Finite Elemente CeraPuc/ products under review, review HERE | Audio Replas OPT-30HG-SC/PL HR Quartz, review HERE
- Anti-vibration accsories: Audio Replas CNS-7000SZ/power cable, review HERE
- Quartz Isolators: Acoustic Revive RIQ-5010/CP-4
- FM Radio: Tivoli Audio Model One