In the world of high-end audio by each year we're all discovering variety of new products, companies and people, that are closely connected with the creation of high-end audio products.  

From the start of the corespondency I’ve had an inspiring conversation with Paul Rassin and conceptual designer and founder of Aequo Audio Ivo Sparidaens. At the Munich High End Audio Show 2017 I've also had a pleasure to meet them both in person. Ivo and Paul are enthusiastic, proud and serious about the brand and products. It's a needed attitude and how things should operate in our niche industry.

Smaller high end audio manufacturers are operating on a different scale then the bigger boys, but often with much more endeavours and more genuine enthusiasm. 

Ensis comes as a result of five years work and many thousands of hours of research and design by the Aequo Audio engineering team. Yes, the countless hours for R & D can rarely be truly calculated and covered once the product is ready to go the market. At the final phase of the product completion one have to pin down the everything connected and take the new born to the uncharted territories of the high end audio market. 

In final calculations, there is never a fair margin, that can fully compensate the "man hour" and sleepless nights. This is also where our industry differ from others. When you deal with the music, you're entering very different realms. Most of the audio designers know about this "higher" dealings. Yes, everything might seems as Sisyphus endeavours, but dealing with the reproduction of the music and being closely connected with this process brings different kind of rewarding experience. This is exactly why, some of the high-end audio products coming from smaller brands can evoke very different kind of aural impact, then some of the bigger brands. You can pay the engineers all that you want, but the end of the day there's no pay check, that cover sheer enthusiasm. From what I've learned and witnessed over the years, most boutique high end audio designers modus operandi reflects 24/7 contemplation. 

Yes, Aequo Audio venture reflect exactly such almost forsaken attitude and the Ensis reflects this within its core structure.


With this particular review pair of Aequo Audio Ensis Ivo Sparidaens decided to take a leap forward and work with a copper patina for the first time. Ivo has spent a lot of work on it by himself, stepping away from his normal designing and measuring work to go into the workshop and learn how to use this special material. There is almost four kilograms of raw and high purity copper added to each speaker and as Ivo ensured me, this has proven to be a very challenging experience. 

If always feels great to receive something special for the review and this exact limited copper edition pair was officially launched at the Munich High End Audio Show 2017 to celebrate the first anniversary of the Ensis. 

I'm always sucker for the out of the box finishes and copper patina is something needed to be see in person for truly appreciating it. In a way Ensis Special Edition Copper speakers reminded me how Romain Jerome choses his particular material for his bespoke watch creations.


Aequo Audio is a Dutch loudspeaker manufacturer situated in Eindhoven, The Netherlands. The area is also known as Brainport: one of the smartest high-tech regions in the world. The designers and engineers of Aequo Audio believe in the credo of the region where they were raised: innovation trough collaboration, research and technology. A fine example of this credo in practice is brand's collaboration with the technical university of Eindhoven where they could use their advanced facilities.


There are really to much technical details and in depth elaboration associated with the Ensis speakers project to cover in a single review. I'm urging you to take time and explore Aequo Audio website for the highly in depth explanations of their approach. Basically, everything follows the Octagon model, that Aequo Audio developed and it became their philosophy as well as part of their logotype.

The Ensis is a very modest sized, truly full-range floor standing speaker. Its stylish shape resembles a music note. The fully closed enclosure is built with interesting in-house developed materials. It provides a three-way driver line-up, engineered to achieve exceptional precision and cleanliness in sound reproduction. This includes an active 10 inch subwoofer, controlled by an on-board amplifier and an analog hardware system for deep and natural lows. The hardware also provides a smart room size and speaker placement correction system, easily controlled by two stylish billet aluminum rotators.

The middle and high frequency section of this hybrid speaker remains passive. Specified as 8 ohms nominal and highly sensitive, it is made to work well with a wide range of amplifiers. The five inch driver is responsible for very open, or pleasantly detailed, midrange frequencies without coloration. It is accompanied by a tweeter system with a concentric dome and ring moving-surface, as well as some new dispersion-improvement technologies. 

The two transducers are time-aligned by the carefully sloped cabinet, and wideband phase-aligned by the low-order crossover, to deliver a spectacular, holographic soundstage.

An unique thing about Aequo Audio, other than the shape of the Ensis and its new technologies, is their design-approach. It is driven by a model created over the years: the Octagon Model. This model was used to evaluate the performance of loudspeakers in general, and more importantly: to design new ones. The model describes eight areas in quality for a loudspeaker. Like Room Acoustics or Dynamics.

Cabinet Construction

The Outer Shell is a sandwich construction of hard woods on the outside and softer woods on the inside pressed with special in-house built hydraulic press with 20t of force. A total 9 layers of wood are pressed together into a compact shell strong enough to support the weight of a car: 3 layers of ultra-stiff wood, followed by 2 layers of softer wood, each of different thickness and divided by another thin layer, then finished with another 3 layers of ultra-stiff wood. This combination is still very thin but with the lowest possible amount of resonance in the entire frequency spectrum.  

Then there is the addition of another unique material to completely eliminate any addition to the sound by the cabinet: Aequo Audio’s Grey Matter CompoundTM that has high stiffness combined with ultra-high weight of 3 times that of granite rock(!), without the addition of toxic materials like lead or mercury. 
It is added to the shell in variable thickness in positions determined by research with accelerator sensors. The front baffle is made of a special and very dense MDF with better dampening behaviour, also stiffer outside than inside and extra heavy. This baffle and outer shell are hold together by a heavy matrix bracing in both vertical and horizontal direction. The cabinet’s front is finished with a beautiful plate made of a mineral filled polymer that has unidirectional stiffness and weight comparable to granite rock, to complete the very best cabinet in size versus performance.

Phase Alignment performance

The low order crossover filter topology is fine-tuned in phase alignment of the already time coherent (by carefully sloped cabinet) mid-bass and tweeter drivers. Phase alignment is not limited to the crossover frequency area but in the entire band of both drivers beyond 20khz. 

Distortion performance

Often thresholds in high end reproduction of midrange frequencies (were our ears are most sensitive to distortion) are chosen at 0,3% for third order and 0,5% for less harmful second order harmonics. For some extensive speakers these are still too hard to meet resulting in specific speaker sound characters.  
Ensis provides ultimate cleanliness with uneven harmonics: third order harmonics are kept around and even below 0,1% above 100hz. No “fairy dust” edginess resulting in listening fatigue, even at high listening levels. The very low second order distortion keeps unrealistic warmth and murkiness out of the sound. It also means rich harmonics of analog electronics can be actually enjoyed instead of lost in the speaker-added sound. Aequo Audio has taken special care and focus towards the ideal balance between even and uneven harmonics for each frequency band. The spectrum is fully covered with ultra-clean foundation by the very capable 10” inch subwoofer into the lowest frequencies also outperforming virtually any other subwoofer in cleanliness. 

Round and round

Every 90-degree corner and sharp edge at the wrong place can lead to sound resonance due to diffraction. Wavelengths with the size from edge to edge will be pronounced. More indirect sound will be added. Ideally sound should slide over the loudspeaker evenly and untouched. Just like an aerodynamic car sliding through the air and using its shape to overcome problems. And only there were diffraction effects can be used as a correction for certain shortcomings, such should be implemented just like spoilers and diffusors on cars are used to overcome lack of grip and unwanted lift. Actually, what one should say or point out on this topic is the fact that not only outside aerodynamics count in speakers, but also those inside the cabinet. Parallel walls mean inside resonances of specific wavelengths/frequencies.  


Counting Crows - August And Everything After 

August And Everything After instantly separate the sonic weed from the sonic fruits. Any hint of the strident detailing become instantly evident, without need for the prolonged contemplation.  The album secret ingredient? Mix and mastering!

This fully analog recorded album, that has ignited many genres in the nineteen nineties is one of the prime examples of compositional and audio job done right. At once you can recognise the speaker's ability to render this unique album with either reserved of with the airy and dynamically contrasted impact.

Music is all about the movement and energy. When something is slowing down the process or covering it with the invisible multitude of layers, then the end result creates a shady reflection of the reality. This as a rule fails to establish strong connection with the listener.

Aequo Audio Ensis loudspeakers formulated an extensive sonic portrait with a signal integrity, that defy the Ensis size and shape. From the quick grasp at their form one might expect something completely then wall of sound, that they managed to create. The Ensis' peer ability has defied usual entrepreneurial endeavours and allowed a diversified and sonorous high end audio reproduction to become alive. Intriguingly refreshing!

Hans-Martin Linde & Konrad Ragossnig - Musik für Flöte und Gitarre 

This is one of the albums, that I like and love in both digital and analog format. It really shows how system and especially loudspeakers are behaving in the spatial domain. There is certain threshold of density needed to portray both Linde's & Ragossnig's guitar and flute convincingly and with enough "air" that justify the word "believable". As simple as some recordings might appear at the casual listening, there is by default a grander complexity when it comes to the single instruments reproduction. I'm not talking about the oversimplified sense of three dimensionality, but about much more demanding juxtaposition of time domain attributes and the trinity of timbre/tone/colour. In the era, where the artificial striving for utter openness prevails as a common trend loudspeakers, that operate outside of this strange quest are always welcome. 
Luckily and inspiringly Aequo Audio Ensis speakers are stepping outside of this direction and follow the path of realism. Ensis managed to convey Musik für Flöte und Gitarre with the refreshing inertia, that carried massive load of spatial cues and information. Ensis' are embracing enough density and follows natural tonality of the real world instruments' DNA. They're capturing atmospheric and spectral shading with a grander aural impact. Materialising the guitar and flute with enough gestalt creates quite a challenge even for the speaker of much bigger size then Ensis, yet the Aequo Audio proud creations encapsulated both guitar and flute with the energy that levelled with close proximity of their given resonant frequencies. Not a small accomplishment at all!

The Kilimanjaro DarkJazz Ensemble - The Kilimanjaro DarkJazz Ensemble

Combining the instruments of the The Kilimanjaro DarkJazz Ensemble into a potent, harmonic whole, that can transmit a viable musical message represents an utterly endeavour.

Ensis have managed to elevate "Adaptaion Of The Bodo song" to the level of the scenic sense, that is usually reserved for a grander speakers. 

By fostering the music's inner richness Ensis have encompassed the The Kilimanjaro DarkJazz Ensemble strenuous compositions with refreshing ease and ability to captivate the core musical momentum. Musical message was reconstructed in the full scale and with the aural visage, that has extended way beyond the speakers with a seldom stance. 

One could say, how Aequo Audio Ensis loudspeakers operate with  strenuous, sophisticated mind and wholesome hearth. 


If you've managed to crawl so far throughout the review, then I'm sure there's a little doubt about how much time and efforts went into the creation of the Aequo Audio Ensis loudspeakers. The Ensis' lightning fast signal response, immersive sound stage, massive power of the subwoofers and lower order crossover  have materialised a box-less sound with a captivating tensional integrity not often exhibited by any speakers regardless the price.  

This was evident with each and every track under the play. Ivo and his team have managed to encapsulate a very different energy  transfer into the core potency of the Ensis. In the era where many audiophiles are marching blindly towards the hyperbolic lifeless sound the Aequo Audio's firstborns are standing out boldly with ability to bring the natural sense of resolution and formed musical structure even at low volume.

Audiophiles often want to hear how this and that product is so much better compared to xxx product. I'm not on the quest of the Robin Hood or trying to established new age guru following. I do believe both of these roles were already taken successfully:) for quite some time. As written many times before, my focus points towards the uniqueness and the way particular product connects with the music. Yes, every cloud has a silver lining...

High end audio reproduction calls for a complex endeavour with technical edifice, that reflect the fervent dedication and understanding of the inner core of the music. Aequo Audio Ensis speakers encapsulates such essence in the absence of typical mechanical imprints.

The collocation of the Ensis's technical and musical attributes were not of opposite sides. Aequo Audio's formulated technical endeavouring created a connecting bridge with the music without focusing on the mere mechanics of the acoustics. Ensis's rather focused on the music's inherited DNA.

Further on, the spatiality and spectral shading of the sound was portrayed in very different way. Music was easily detached from the speakers and the sonic rendering created the grander aural venue, with the sonic projection of impressive density. 

Ensis have shown their multi-faceted nature, that could follow the music genres with a captivating pace and with the sonic magnetism, that can easily lockdown the listener into a prolonged and listening fatigue free aural enjoyment.

Aequo Audio Ensis speakers are of rarer loudspawkrs's breed that rewards the listener with prime audiophile and music lover attributes. 

For what they represent and even more importantly at what extend Ivo Sparidaens and his team managed to balance the Enis's inner core calls for some serious highlighting. I'm happily awarding Aequo Audio Ensis speakers with Mono and Stereo Highly Recommended Award.

Aequo Audio Ensis speakers's aesthetics and sound reflect the 21st century values and demands, that are highly coveted by both strident audiophiles and emotionally engaged music lovers. For the firstborns, these speakers strike with the surprisingly high exclamation mark. 

Watch out for out for the Aequo Audio future imprint! 

Matej Isak


EUR 24.000 (without VAT)


  • Size: 116 x 31 x 29 cm
  • Sensitivity: 90db
  • Enclosure: Floorstanding, Closed
  • Frequency range: 10-40.000hz, *low frequency extension and gain is steplessly adjustable to match room size and acoustics.
  • Impedance: 8 ohms nominal (for all amplifiers rated 2 to 8ohm)
  • Tweeter: Innovative high frequency transducer system with concentric fabric ring and dome design for extended frequency bandwidth, billet aluminum dispersion cone on carbon fiber rod to eliminate high frequency irregularities and fix the middle dome to eliminate membrane resonances. Full symmetric motor for super-fast response and very low distortion. Enhanced horizontal dispersion lens ensures 3D holographic soundstage and imaging in all rooms.
  • Midbass: High self-dampening polypropylene blend cone, low loss surround and suspension and well ventilated built to avoid large excursion compression. Hexacon voicecoil, Kapton-aluminium former. Powerful motor with very low distortion and super-fast Symmetry Drive (patented).
  • Subwoofer: 10 inch subwoofer with aluminium cone, very low distortion motor with heat resistant anodized voicecoil that can travel 50mm in symmetric magnetic field for clean and fast dynamics. Active powered and controlled by innovative system with full analog signal path to easy adjust placement and room size and produce a natural deep roll off in the lowest frequencies.
  • Crossover: Passive, balanced, in-phase crossover filter with only high-end capacitators and inductors. Unique filter topology without capacitators in line with the midbass for uncolored signal performance.
  • Weight: 25 kg


Aequo Audio
Dikkenbergstraat 1
5628 EA Eindhoven