Duevel Planets


Author: Karsten Hein

Category: Gear & Review

Tag(s): Loudspeakers

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When I first met Alexi, this was during our role as fathers of elementary school children. However, it did not take long before we discovered our mutual interest in home audio equipment. I was intrigued by the fact that he was a seasoned technician in electronics who had preserved the heart of an explorer and did not, on principle, object to the significance of interconnects. As I found out, he even ran a pair of single-wired Kimber cables from his NAD streamer amplifier to his speakers. From this combination, I took it that there was likely to be some room for meaningful conversation.

As it turned out, Alexi's speakers were a pair of smallish-looking omnidirectional 2-way towers with down-firing bass ports. They had the words ‘Duevel Planets’ printed on them and each cabinet held two shiny spheres suspended above its upwards-pointing drivers. The woofer-to-midrange driver featured a kevlar diaphragm, whereas the soft-dome tweeter was recessed behind a horn construction. The otherwise non-frills cabinet had a clean anthracite colour coating and was raised 40mm off the ground by four rubber absorbers. These also served as acoustic decoupling from the floor.

However, no matter how long I looked and pondered over the design, I did not have the faintest idea of what to expect from these speakers, especially, because they came from a small German manufacturer of whom I had never heard. Alexi informed me that Duevel was the founder’s family name and that the Lower-Saxony-based company specialised in building omnidirectional loudspeakers, most of which were larger and also heavier than the Planets. He further told me that the Duevel Planets had been praised as unrivalled in the sub-1,000 EUR category, and performed near the level of this manufacturer’s far more expensive models. I was hard-pressed to believe this account and fully expected their sound signature to resemble their physical appearance: small, airy, slightly metallic and tonally thin, perhaps.

When Alexi first started his convenient NAD streamer amplifier, my impression was that the music sounded a little thin and disorganised. I had trouble discerning an accurate center stage image but could also see that the distances from the speakers to the front wall and the distance between the speakers and the listening position were not the same for both channels. The speakers had clearly not been set up taking into account the specific resonance frequencies resulting from the room's dimensions. Although the NAD amplifier offered on-board software for room-adaptation as well as a microphone for calibration, this feature had not yet been fully employed. The random overlapping of frequencies and heavy smearing of running times I could have easily taken as confirmation of my suspicions towards the design.

I spoke to Alexi about my concerns regarding the positioning of his speakers in the listening room and also offered to lend him a power amplifier from my stock in order to test his speakers with this. However, we agreed to first swap loudspeakers for a few days: He would get my Tannoy XT8F, while I would audition his Duevel Planets. At the time, I thought that he was getting the better deal for sure, but I think we were both excited to get new insights and gather experience with different loudspeaker designs. As it turned out, dragging the large and heavy Tannoys over to Alexi’s house in our children’s handcart proved to be quite a challenge, whereas the eleven kilo Duevels could easily be carried and pulled over to our house. This was the Duevels' first obvious benefit.

We decided to set his Planets up in our upstairs listening room, which was of considerable size and had slanted walls that helped to deflect some of the reverberations. The Duevels were going to replace a pair of Epicure EPI 500 that had been my favourite speakers due to their natural bass and tonality for some time. We gave the Epicures a final audition, playing tracks from 2Cellos, Diana Krall, and Norah Jones and then placed Alexi’s Planets in the exact same position. We played the same tracks again and were both more than a little surprised at how tonally similar the Planets sounded. Alexi remarked that the Duevels had slightly sharper imaging than the Epicure, and I noticed a mild leaning towards analytical and technical sound on the side of the Duevels.

In this first position, the Planets were positioned directly on our hardwood floor with one meter distance kept between the bass driver's central axis and the room’s front wall. Happy with the findings of our first listening session, Alexi and I parted ways. Over the next few days, I came back to the Planets to experiment with different placement options. I noticed that bass response and depth of soundstage strongly depended on the triangular relation between the speakers, the room’s front wall, and the listening position. And although I did realise that this was the case with all speakers, the effects seemed more pronounced due to the omnidirectional nature of the design. The front wall became an integral part of the listening experience, and differences in shape, texture, and firmness of that wall would have an effect on how the music sounded.

Bass became stronger as I moved the Duevels closer to the front wall. I found that imaging stayed remarkably sharp until about 50cm distance. Whereas at one meter wall distance I had been lacking bass punch and the lower frequencies of vocals, the speakers sounded tonally richer and fuller when nearer to the wall. Of course, the wall distance will affect room resonances and bass modes relative to the seating position, and I was glad to see bass increasing again once the speakers were positioned further than one meter from the front wall. In one instance, I moved the Planets to a position half-way between myself and the listening position and was pleased with the immense depth of stage I was experiencing.

Judging from their looks alone, I would have thought that the upward thrust of the drivers paired with the two spheres would make the Planets susceptible to imbalances caused by the room dimensions. In our upstairs listening room with slanted walls, the left speaker only had about 50 cm of air above, whereas the right one had about three meters of empty space above it and also plenty of room to the right. However, my concerns were unfounded, because the spheres served as fixed points of first reflection, radiating the sound around the speaker rather than up. As a consequence, the Duevels sounded just as balanced as all the loudspeakers I had auditioned before them. If anything, the center image felt more natural.

As I was still feeling a little bothered by the Planets’ accurate and technical sound, I experimented with pads and carpets that I placed under the speakers. This helped shift the balance from listening to the character of a microphone towards hearing the voice of a human singing. I would suspect that the best option would have been to place a thick board underneath the speakers and to decouple this via felt pads. But since the Planets were not mine, I did not want to make the investment. Instead, I achieved good results by placing felt pads or floor matts underneath the four feet. Either way, the speakers benefitted from some form of additional decoupling from the hardwood floor. The floor matts had the advantage of keeping the bass reflex at the prescribed distance.

I found that the Duevels were capable of creating a naturally-sounding sound stage that was both deep and wide. This impression grew stronger with increased distance to the room wall. Given their relatively small size and shape, however, placing these speakers midway towards the listening position would make them stumbling blocks in most listening rooms, exposing them to the risk of being toppled over to one side. Their more monumental brothers and sisters, on the other hand, would present more obvious obstacles and also resist the occasional collision without the immediate risk of damage. This could be worth a consideration when deciding to make a purchase.

At the correct relative distance to the wall and seating position, the Duevels produced a tonally correct sound that was neither thin nor boomy. Vocals sounded clean, open, and realistic once the correct coupling towards the floor had been achieved. Imaging was surprisingly sharp for an omnidirectional speaker system, and the developers Annette and Markus Duevel were obviously in control of the relevant acoustic dimensions when they designed these speakers. I was surprised by the accurate phantom center despite the uneven layout of the room. And I was even more astonished by the persistent stage effect as I was walking through the room. Similar to a living room concert—and we have had some of those—the stage did not change position. It seemed as if the Jazz combo was still playing in the exact same position, no matter from where in the 70 sqm room I was listening.

From the listening impression alone, it was difficult to believe that the Planets were entry-level speakers that had been sold for under 1,000 EUR. With my eyes closed, I would have assumed that I was listening to far taller speakers with a heftier price tag. With the eyes open, there were some indicators that the price was perhaps justified. Inspecting the Planets from the floor upwards, I first stumbled over the affordable-looking rubber feet that kept the speakers suspended without the addition of a defined base plate with spikes towards the ground. The binding posts, too, were designed to only take one set of bananas or spades without the option of bi-wiring. Given the limited mass of the woofer, I did not feel that there was need for bi-wiring, however, the absence of this option did not strike me as state-of-the-art.

The cabinet itself was a simple box of medium density fibre that had been neatly colour coated. Although my wife rather liked the look, I would have preferred a more reassuring instrument-like appearance using real wood veneer. The font and style of the lettering did not exactly scream High End design, either. Instead of well-seasoned and sophisticated, these speakers looked young and cool. And this coolness-factor was further accentuated by the two seemingly cold spheres hanging suspended above the drivers. Since both of the drivers were pointing upward, keeping them clear of dust might prove to be a challenge. The mouth of the tweeter’s horn had a metal grille to protect it from children’s fingers, however dust and cleaning liquids passing the grille would remain out of reach. Non of this, however, appeared to have been an issue on my test specimens that still looked clean and in great shape. Perhaps a testament to Alexi’s good care.

In my listening tests, I enjoyed how the Planets maintained stage size and instrument location. The fact that some of the music was reflected upward gave string instruments a life-like appearance. The speakers did not betray their position nor the materials used on the cabinet or spheres. They did not sound wooden, boxy, or metallic. Even in our large listening room, playing music at volumes of between 60 and 80 dB was possible without audible compression (measured from the listening position). Duevel rated the Planets at 50 watts RMS per channel, and our Dynavox VR-70 tube amplifier had no difficulties driving them. Low-bass presentation was sufficient and even surprising given their size. I could not detect any phase issues, and their timing was excellent. Rated at 85 dB (1W / 1m), the Planets would benefit from large amplifiers despite their relatively low power tolerance.

Although I could not find any information on frequency response, the thought that anything was off or amiss never once crossed my mind while listening to them. Sonically, the Planets were close to some well-regarded classic speakers and did not follow the path of so many modern showroom squeakers. Astonishingly, this character remained largely in tact when walking though the room. On very rare occasions, I missed the piercing power and attack of piano keys, especially when the Planets were standing further away from the wall. And I did notice that the full extent of tonal balance needed at least 60 dB of volume. Below this, the treble seemed slightly dominant. This did play a role at least once when we had guests for dinner, and I was looking for some mild background entertainment. In this scenario, I would have wished for stonger bass foundation to support tonality.

I never played music at volumes where the size of the woofer seemed to matter. And after listening to Jazz albums by Diana Krall, Helge Lien Trio, and Jamie Saft (among others), I was pleasantly surprised how well the Duevels played Jörg Hegemann’s fast and furiously dynamic CD album “High End Boogie Woogie” that included some wonderful double bass runs. Due to their omnidirectional characteristics, experiencing the music with friends and sharing a similar experience, all at the same time, was possible for the first time. Audiophiles will agree that sharing the pleasure of listening is often a challenge, because, given the narrow sweet spot, we can only guess what the other person is hearing.

While a sceptic at first, I could see that omnidirectional loudspeakers such as Alexi’s Duevel Planets had a deserved place in the heart of HiFi enthusiasts. Given Annette and Markus’ command of this technology, it was fair to say that the Planets shared some highly audiophile characteristics and were fun and easy to listen to over extended periods of time. Omnidirectional speakers had the potential to create a more natural stage that maintained its realism in many positions of the room. For those of us who prefered to listen to acoustic instruments played by small combos, these speakers provided the perfect setting. As all audiophile speakers, the planets had been designed to perform best at living room volumes. Any deviation from this (be it higher or lower) would produce less-than-ideal results.

For my part, I decided to hold on to the Planets for a few more days and enjoying the music before returning them to their rightful owner. I was also looking forward to helping Alexi in calibrating his own NAD system to his listening room, first with my Tannoys and then with his Duevels. I now knew that they were well worth the fuss.

Test system: Marantz CD-17 via HiViLux Reference SP/DIF cable on Cambridge DAC Magic 100 via HBS Silver Solid-Core Interconnect on Dynavox VR-70 via Belden 9497 in Y-wiring on the loudspeakers


  • Type: floor-standing 2-way loudspeaker
  • Design: omnidirectional, vented cabinet
  • Frequency response: N.N.
  • Power handling (RMS): 50 watts
  • High-frequency driver: soft-dome tweeter, horn-loaded
  • Midrange-to-bass driver: dynamic, kevlar diaphragm
  • Diameter of spheres: 98mm and 58mm
  • Distance between spheres: 48mm
  • Crossover frequency: 4,100 Hz
  • Power sensitivity: 85 dB
  • Nominal impedance: 4 Ohms
  • Dimensions: (H) 840mm x (W) 260mm x (D) 156 mm
  • Weight: 11 kg
  • Country of manufacture: Germany
  • Year(s): 2012
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