Like yours truly, many of you also visited SoundSpace Systems at the Munich High-End Audio Show 2019 and left with a lingering impact. Not only by Michael Plessmann’s out of the box music choice but by the sheer power of music delivery. 

As encountered at the Munich Show there is something uniquely and beautifully different about the SoundSpace Systems speakers. You can further discover during the review of how Plessmann’s creations are no happy accidents but carefully crafted musical boxes. They use a lot of unique solutions, proprietary materials, and complex inner structure.  

Plessmann’s love for audio and high-end goes way back in his pre-twenties when he already built his first pair of speakers. Decades later, years of music listening, exposure to live concerts around the world and in-depth research in materials, parts, and techniques concluded in the making of two speaker models. They were built from the ground up with one clear goal in mind; to reveal the real emotions and the nucleus of the music. 
Plessmann holds a doctorate in physics and this helped him tremendously with the conceptualizing of the speakers. Every high-end audio speaker designer faces tons of challenges and the ability of lateral thinking is without a doubt more than helpful in understanding the processes, materials, psychoacoustics and nonetheless most importantly, to draw the right final conclusions. In the era where the advancement of technologies offers practically endless choices making the right decisions is pivotal in creating something meaningful. 
In order to truly stand out from the crowd, different kinds of measures are needed. Many people are scared of moving out of the safe/comfort zone, but only when barriers are pushed to the extremes the formation of (un)expected state of the art attributes can occur. And Plessmann is a man of action and daring deeds. 


The creation of Aidoni obviously involved some basic acoustical and electrical measurements as anyone would expect. Though, the main decision with drivers’ selection in the basic layout and more importantly in the trimming and fine-tuning were done in intense listening sessions.
SoundSpace Systems has some fundamental believes about music reproduction. Every music has a specific texture. Recreating this texture in the listening room is SoundSpace Systems’ first objective because it allows the listener to look far more intimately into the music.
“Once we have arrived there we look for getting the feel right which is normally just tweaks in the sonic balance. (3D imaging quality and PRaT (pace, rhythm, and timing) are very good indicators if we are getting close to the targeted sound). Aidoni was created as the statement of SoundSpace Systems’ belief about how reproduced music should sound and feel.”
Music is made to tell us stories, to push us beyond or to draw us in. It is produced from a single instrument or voice or from a huge group of musicians like a choir or a full symphonic orchestra. A leading-edge speaker like Aidoni should be capable of recreating the specific texture of all these musical situations. In other words, they were created to provide…
  • The „Heavy Metal feel“
  • The „Camp fire feel“ of singers/songwriters
  • The „Church feel“ of choirs
  • The „Avantgarde feel“ of experimental music
  • The „Fairy tail feel“ of a romantic opera
  • The „Be there feel“ of live concerts
  • The „Grandezza feel“ of a symphony hall


Ribbon tweeter from the professional PA world that has the following features among others:
  • Frequency range from 800 Hz up to 25.000 Hz,
  • Maximum undistorted SP level above 125 dB,
  • Power peaks beyond 1000 W without any cooling,
  • Sensitivity above 100 dB/W/m,
  • Not a compression driver
  • Membrane mass is less 50% than that of a comparable compression driver.
The driver is heavily modified by altering the resonance volume and creating direct through connections to the ribbon membrane. The addition of the tractrix horn-shaped waveguide supports the lower frequencies of the tweeter big time. If this driver is driven to maximum performance no-one will be in the room anymore unless they have a severe hearing problem…
Two Supravox bass-midrange drivers with the following features:
  • Exponentially shaped membrane
  • Lightweight paper membrane
  • The suspension is also paper
  • Randomly oriented cellulose fiber made from a special pulp formula drivers
  • Used since the 60s in many radio stations and studios
  • Flat frequency response between 100 Hz and 4000 Hz
  • Linear extension of 10 mm
  • High sensitivity
  • Low distortion
The already low distortions are further reduced by a proprietary resonance controller in a dust cap free modification of the driver. The pre-chamber loading not only helps to improve the linearity of the frequency response but also removes resonances and distortions created as an unwanted by-product of the suspension.
In the chosen D’Appolito set-up the midrange matches the timing and speed of the tweeter. This is one of the few drivers that perform such a task. The doubling-up also creates enormous sound pressure levels so that rock concerts impact at home can materialize to an impressive extend. Finally, the midrange purity and speed of this driver creates a presence and an immediacy that is rare in HiFi. Plassmann says: “It recreates voices that make people cry.”


The rear tweeter can be adjusted by the listener to create the right amount of airiness for the listening situation. The quality and performance of this driver are much better than the main tweeters in most High-end speaker designs.

Some highlights:

  • AMT 
  • Neodymium magnet system
  • Highly dynamic membrane made from Kapton and aluminum.
  • High sensitivity ( 98 dB/W/m)
  • Frequency range from 4,000-30,000 Hz.


These drivers move enormous amounts of air and they go very low with ease. The application use of these woofers is involved with sound systems for concert halls or rock concerts. Underneath stages, they come in dozens, but for a private listening room, four of these are usually more than enough. Here are 15“ woofers info and features:
  • Paper cone
  • Dual voice coils
  • More than 800cm2 of effective membrane surface
  • Linear extension of +/- 1,1cm 
  • The resonance frequency of 21 Hz
  • Sealed resonance chamber


At all critical junctions, SoundSpace Systems is soldering the connections directly onto the board instead of using the usual multi-pin connectors that are typical for the professional PA industry.
An extremely versatile and dynamic DSP made in Germany that is highly synergistic with the bass amplifier is being used. The PA origin ensures long term stability under rough conditions.
Here are a few of the features of the DSP unit:
  • DSP  based crossover 
  • Solely in the active bass compartment
  • Developed for professional audio applications
  • 122 dB dynamic range
  • 96 kHz sample rate
  • Bandwidth 10 Hz – 40,000 Hz
  • Latency below 0,6 ms
  • Could be used for room adjustments
  • XLR or RCA input


These amplifiers are designed to serve live events or tour sound productions. They offer extremely low noise and what it’s called in the audiophile term, the extreme black background. 
  • Class D amplifier adopted from professional PA loudspeaker applications
  • Super high voltage rails
  • Sustained non-clipping power burst handling
  • 1000W RMS into 4 Ohms
  • Signal-to-Noise ratio above 120 dB
  • THD 0,05% 
  • Damping factor above 1000 below 1000Hz
  • Extremely robust  operations
  • Universal mains 65 – 260V, 50/60 Hz


Here are a few of the highlights of the analog crossover

  • Coils and capacitors are all Mundorf 
  • Silver/Gold or Silver/Gold oil technology. 
  • air coils with extremely low resistance. 
  • capacitors are all set up as capacitor banks.
  • Low tolerances 
  • Highest possible mechanical stability.
  • Mundorf’s supreme winding technology conceals any inductivity in capacitors


All wiring is hand made by SoundSpace Systems and specifically designed for the individual drivers. 
Highlights and features:
  • Solid core 
  • High purity cryogenic silver, for very few of the connections a core of monocrystalline copper with a thick silver coating is added. All cores are and 
  • PTFE coated. 
  • Wire guards are hand made from „Klangholz“
  • Terminals are all silver WBT terminals
  • Internal wire connectors are residing on „Klangholz“ 
  • Solid silver connectors (hand made by SoundSpace Systems). 
  • Wonder Solder „Signature“ is the solder of choice
With Aidonis you’ll find in a 6 dB high pass 6-10 capacitors instead of one. This helps to manage the speed and capacity of charging and discharging the capacitors and supports the accuracy of musical reproduction big time. Mundorf’s winding consumes four times the material input compared to a conventional design, but micro details and resolution are greatly improved by these capacitors.


The cabinet is made from a rigid three-layered composite, centered around a bamboo core that builds up the woofer compartment and also the frame system for the upper frequencies. On the inside, the ceramic shell is used that ensures the removal of unwanted resonances. The outer shell can be chosen individually in Piano Black (the review mode) or other colors, or solid timber wood (Klangholz).
The overall appearance is shaped to avoid any standing waves and strictly follows Feng Shui principles and applies the Golden Ratio. The Golden Ratio can be found in nature, galaxies, artwork, architecture, literature, and many other areas. 
As know, Leonardo Da Vinci perfected its use in every single painting he did. It is the secret to aesthetics. 
Plessmann explains how Feng Shui is concerned with order, balance and the harmony of heaven and earth. The combination of both leads back to the magic of music in order to enhance the enjoyment of life by bringing it into harmony and balance with its surroundings.
Aidoni is composed of three main modules and two supporting modules: 
  • The tweeter module with its tractrix horn. 
  • The midrange module which is set up like a folded open baffle.
  • A sealed bass module.
  • The passive crossover module.
  • The bass management module which includes the DSP and the amplifier. All five modules are seamlessly integrated into the cabinet but functionally they are autonomous.
50kg bronze plate is used at the bottom of the Aidonis. This form a very solid foundation and as utterly tested provides a more focused and balanced sound.


Drivers are compacted as much as possible (allowing a much closer listening distance than comparable speakers). Each and every driver is heavily modified and they are carefully matched to get the performance that Aidoni needs.
Tractrix horn and pre-chambers are adjusted in such a way that allows the sound wave impedance to extend the usable frequency range of the tweeter and the midrange drivers.
Side based Push-Push bass implementation minimizes distortions from the bass drivers and phase-coherent integration of the bass drivers at the microsecond level is pushed to the extremes to ensure proper speed and attacks. 
Aidoni uses strictly 6dB electrical crossovers including the bass module. The overlap between the drivers is enormous, so a phase coherence and synchronicity matters a lot. When this is done right, the results are unrestrained sonic projection, that we perceive as naturalness.
Interestingly the bass/midrange crossover point is below 75Hz. This optimizes the acoustically allocation of the bass. 
The midrange/tweeter crossover point is below 1kHz, operating underneath the presence band of listening where the human ear is supersensitive. Another feature that permits Aidoni speakers to present micro and macro details in a different fashion than usual norms! 
Aidoni speakers use no electrical impedance adjustments, suction circuits or resistors applied. This is a puritan design take and this shows with every note being played.


SoundSpace Systems Aidoni speakers are capable of delivering something that is very hard to achieve regardless of the price sticker… They can play the music at the right volume!? 
Usually, cranking up the volume can lead to distorted sound or playing tunes at moderate volume stripes away the bass foundation, the details and music’s density. Not with Aidoni! 
SoundSpace Systems flagship speakers require an extreme caution at listening. With Aidoni’s distortion-free impact it’s very easy to cross the safe volume threshold and not knowing it. 
Aidoni speakers juxtaposition of being unapologetically brutal yet feather-like gentle is hard to comprehend. Such inverse nature might sounds a bit controversial, yet the real-world test easily provides a hands-on experience that is quite an ear and eye-opener. Aidoni speakers can handle both music’s extremes nonchalantly.
Considering the variety and dynamically intense selection of the reference tracks used to construct, voice and fine-tune the Aidoni speakers instantly reveal why they can sound the way they do:
  • Metallica – My friend of misery
  • Massive Attack – Angel
  • Led Zeppelin – Whole lotta love
  • Ry Cooder – Volver Volver (live in SF)
  • Jazz in the Pawnshop
  • Dire Straits – Brothers in Arms
  • Francy Boland – Fellini 712
  • Shostakovich – Symphony #15
  • Einstürzende Neubauten – The Wille/Nicky Telegrams
  • Leonard Cohen – Avalanche
  • Cameron Carpenter – Bach Toccata /Fuge D-Dur
  • Cantate Domini – Hosiana Davids Sohn
  • Elisabeth Schwarzkopf – Strauss letzte Lieder
  • Anton Bruckner – Symphonie #8
  • Richard Wagner – Rheingold
SoundSpace Systems Aidoni speakers deliver copious amounts of detail and unexpected resolution that exceed any close-minded expectations. More than that, Soundspace Systems’ flagships can reveal micro-timing deviations with mind-blowing precision. This feature alone is worth all of all the excitement. Anything related to timing is crucial for the recreation of a believable aural illusion and Aidonis is splendid in this regard. 
Plessmann prefers that his proud and beloved creations do the “talk”. And do they speak out loudly and proudly! Aidonis’ fluent and ghastly ability to render the music with tremendous impact is intimately related to their unique DNA. They were conceptualized as the cost no object transducers without dynamic limitations…  
In absence of usual marketing pompous and sweet-talking the Aidonis offer an unrestrained dynamic tour de force performance and equally importantly spellbinding connection with the music’s inner core.
Aidoni speakers are making their statements with their confrontational nature that instantly ignites all the rights inner triggers by bypassing the usual sensual safeguards. This is another rare feature that most high-end audio loudspeaker designers should strive for. It also puts Aidonis in the league of their own.  


These speakers were clearly designed from the ground-up to provide a purest and uncompromised music pleasure. Aidonis deliver a non-conformist approach that most intimately reflects the designer’s mind. Plessmann is an avid music lover, traveler, and frequent concert-goer. Consequently, SoundSpace Systems speakers reflect his passion and dedication for the enjoyment of exquisite things that life has to offer. Aidonis were designed to derive utmost aural pleasure and excellence and Plessmann is no shy of showing it.
Plessmann painstaking efforts for music perfection, unaltered reproduction and life-like energy impact are encapsulated with his beloved and proud creations.  
Aidoni speakers were not designed to curb the enthusiasm, but to fully exploit and deliver the unrestricted emotional and energetic music impact. Many loudspeakers claim to deliver unchanged energy and sheer power of the music. Yet… In reality, it’s too evident even to an uninitiated how any physical constraints cannot provide such heavenly pleasures. The law of physic might be simple, but is never simpler…
Aidonis can operate at an average sound pressure level of 60dB that reduces overtones to less than 40dB without losing composure and also at 90dB which allows them to create peaks at 110dB without sounding congested or nerve-wracking. This is the feature one would more likely associate with horn speakers! 
With their given high-efficiency Aidoni can be easily driven even by the moderately powered tube amplifier without leaving out the full scope delivery of micro and macro dynamics. But, their ultra-wide dynamic expanse demands a careful partners. Not every amplifier (and preamplifier) is a suiting match. A careful selection is needed to let the Aidonis really sing as they’re meant to. I’m always pointing out about the importance of proper system gain distribution and Aidioni speakers are ultra sensitive in this regard. It’s not really about matching them with similarly price gear, but about the establishing the balanced overall system gain. Only then the Aidonis will fully bloom and reveal their enormous potential. 
Like Pirol, Aidoni uses DSP based active bass. With all of the OEM offerings out there the proper active bass implementation feels like an easy affair. On the contrary, this is one of the hardest tasks to accomplished and it’s a task of Sisyphus proportions even for a seasoned audio designer. While technical and theoretical implementations feel like a no brainer on the paper in a real-world the task of seamless bass integration with the rest of the drivers represents one of the utmost challenges. 
Why? Even with best calculations and high-speed processors it always comes down to the timing and phase. The most complex calculations alone are not per se recipe for success. The proof is in the pudding… If active bass is not integrated seamlessly the speakers can too easily sound like a usual, mediocre stand-mount monitor with an active sub-basses placed somewhere near them. I’m talking about the separation phenomena, where the subwoofers are not acting in sync with the rest of the drivers, but acting solely. Not exactly the most wanted feature for any high-end audio loudspeaker. Especially for anything that is kittened with the high-end audio label, yet this unsavoury junction can be easily noted at any high-end audio show…
Like with the Pirol the Aidoni DSP application provides a surprising well-implemented integration without frequency “black” holes or bumps. 
When needed Aidoni provides submarine-like depths, erupting suddenly and without delays. When paired with properly matched power amplifiers bass is rich, articulate, focused and ready to fill even large listening environment space with authority. 
Aidoni speakers can reveal the emotion and the power captured in music. This is a rare, yet “muss seine” attribute for any high-end audio loudspeaker. 
As noted many times over the review, everything about the SoundSpace Systems speakers is out of the usual norms. The weight, the selection of drivers, the enclosure, the energy impact and nonetheless the price, that roughly translate literary to 1000 EUR per kg :).

Aidoni speakers were not conceived to be trivial, but a sculptural aural object of art, that ignites all the right triggers on the utmost plane. They embrace cost no object, take no prisoners approach. SoundSpace Systems Aidonis encapsulate more than five decades of Plessmann’s sheer enthusiasm for music and this shows from track to track, album to album.  

Plessmann is an avid concert-goer with an impressive history of concert attendance of famous music halls and concert venues around the world. For him, the ultimate music reproduction must decipher both Einstürzende Neubauten and Anton Bruckner at the same plane, with the same impact. 
Aidoni is an iconoclastic loudspeaker with the most unique set of advantages! They were created to provide exquisite music de jour. Unlike many so-called speakers’ icons, SoundSpace Systems Aidoni speakers can deliver the concrete aural actions/pleasures and not symbolic pledges. These are the extreme performers for extremely demanding aficionados.
Aidonis’ unique aesthetic language comes with a place for everything with everything in the right place. Similar to SoundSpace Systems’ Pirol loudspeaker the Aidonis are influenced by the strong and unmistakable traits of Feng Shui and Golden Ratio. This makes them visually and listening environment friendly without needed contemplation that usually requires additional intellectual efforts to place an object into space to fully enjoy it. When the design cues are implemented right, the object simply sits in the place and blends with the surroundings. 
SoundSpace Systems Aidoni speakers require no closer inspection operation or heavily loading of the left and right brain hemispheres. The two start to ignite their synergetic visual and sonic crosstalk at the higher-order degree within a few notes’ strike. SoundSpace Systems Aidoni speakers provide unusual disappearing act, letting the music to touch listener without any hard-tasking endeavours. The music simply radiate and floats into the space, presenting one of the kind, true upper echelon aural illusion.
At its given prices Aidoni will undoubtedly ignite the topic of Veblen’s Conspicuous Consumption. The current high-end audio pricing certainly reflects the era we’re living in, yet is no different from the luxurious mechanics of other industries. These speakers cannot be mass-produced and were certainly not envision as such. They are extreme aural via mediums with no compensations. As other similarly priced products they always find a happy home and a few lucky people to enjoy them.•
Matej Isak


– 300.000 – 360.000 EUR
– Natural wood 360.00 EUR 


  • System:    3way
  • Power rating:    200/ 500 W
  • Frequency range:    18 – 32.000 Hz
  • Impedance:    6 Ohm nominal, 3.2 Ohm minimum
  • Efficiency:    101 dB/W/m
  • Maximum SPL:    126 dB
  • Dimensions: (H x W x D)    148 x 44 x 67 cm
  • Weight:  320 kg per speaker


SoundSpaceSystems GmbH
Sensburger Allee 5A
14055 Berlin
Tel: +49 (0)30 91 45 99 73