Nubert nuZeo 4 review

STEREO GUIDE verdict

94%

94%

Highlight

The Nubert nuZeo 4 marks the entry into the new premium class of the direct mail order company. In the review, the 2-way compact speaker performed as brilliantly as the lacquered housing would suggest.

Advantages

1. Extremely deep and rich bass for a compact speaker
2. High resolution and precision
3. Also suitable for wireless surround systems

Disadvantages

1. Somewhat nerdy setup via Bluetooth app
2. No direct wireless playback to the speakers possible

• Sound: Tonal Balance/ transparency

  9.5
• Sound: Bass / Dynamics

  9.5
• Sound: spatial imaging

  9.3
• Ease-of-use / Connectivity

  9
• Price/Performance

  9.5

Nubert stirred up the future hi-fi scene with the announcement of a wirelessly controllable reference active speaker series. It is called nuZeo, and the compact nuZeo 4 model immediately found its way into our review. The name deliberately sets it apart from the previous nuPro models. Although the nuZeo is also intended as a reference monitor for the studio, the focus is on uncompromising high-end sound at home. In addition to the single compact monitor, there will also be two floorstanding speaker models, the slim nuZeo 11 and the more massive nuZeo 15. A center speaker is also intended to make surround fans want to get active.

As new as the name and price range are, the nuZeo is classic in terms of connectivity and application: preamplifier and D/A converter are built-in, the wired playback options are more than diverse. If you prefer classic sources, you can use a pair of nuZeo as a complete system without hesitation. According to the manufacturer, the fact that they are holding back on new standards such as HDMI and even more so on streaming is fully intentional in terms of future viability.

The true strength of this active solution is only revealed in combination with a wireless-capable Nubert preamplifier as a playback device. With the new nuXinema preAV, even a (partially) wireless surround solution with Dolby Atmos is possible. Can the new NuZeo series knock the Canton Smart series off its throne, which has virtually had a subscription to this concept until now?

Studio monitor or streaming?

When looking at the speaker’s connection panel, the XLR socket immediately catches the eye. As with the nuPro X series, it accepts either analog or digital signals. This is more in line with the practice in the pro audio sector, but is also increasingly becoming the standard for high-end electronics in the upper class.

A pair of classic RCA inputs is probably the most common analog connection variant. There are also two coaxial S/PDIF ports, for example for CD players or streaming bridges. However, USB, optical input and HDMI are missing, which limits its use as a “plug & play” compact system.

The NuZeo is usually controlled via the free Nubert X-Remote app for Android or iOS. However, if the smartphone is empty or misplaced, there is a rotary/push button on the back of the speaker that makes it easy to select the source and adjust the volume. This is also used to navigate through the extensive internal settings menu.

The wireless concept of the Nubert nuZeo 4

The Nubert nuZeo 4 completely dispenses with direct Bluetooth playback. According to the masterminds behind the concept, this is only logical in terms of sound quality. As there is also no built-in network receiver, WLAN or streamer for reasons of future viability – after all, a Nubert loudspeaker should never become obsolete – the question rightly arises as to why we are reviewing the NuZeo on a portal for future hi-fi.

The answer lies in the wireless concept of the nuZeo series, which is very similar to the nupro-X. It is based on a proprietary technology called X-Connect. In the simplest version, it ensures that one speaker in a stereo set is defined as the master, handles all sources and sends the signal for the other channel wirelessly to the slave speaker in Hi-Res resolution and without latency. The complete stereo system without cables between the speakers is ready.

nuGeduld: The nuZeo 4’s Bluetooth app proves to be a bit nerdy

In practice, however, this exercise took longer than you might think, because you have to connect each of the two speakers individually to the Nubert X-Remote app via Bluetooth in order to assign them their respective role (master or slave) and position (left or right) in the nuZeo duo. This is not always intuitive and sometimes leads to minor problems. After successful setup, the master speaker can also address the slave wirelessly via a proprietary radio link.

But the nuZeo 4 can do even more: If you purchase a component from the compatible Nubert electronics range as a player, you can control both speakers wirelessly. The Nubert nuConnect Amp XL, for example, is a well-equipped stereo streaming amplifier.

But things get even more exciting with the Nubert nuXinema preAV AV preamp. This compact decoder preamp not only provides numerous HDMI inputs and the decoding of modern surround formats such as Dolby Atmos and dts:X. Another highlight of the concept is that wired and wireless channels can be mixed as desired with nuPro or nuZeo models.

High tech in the sound conversion department

The drivers have been completely redeveloped for the nuZeo series. The bass with the characteristic baked carbon fiber cone looks truly high-tech. At the same time, its huge surround also radiates: “I can do endless cone excursion”. This is certainly necessary in order to mobilize decent levels at the advertised lower cut-off frequency of 29 Hz.

To ensure that the massive surround is not at the expense of the effective cone area, Nubert has opted for a maximum driver size: 20.3 centimeters in diameter of the basket, which corresponds to exactly 8 inches. They just about fit into the 24 centimeter wide loudspeaker sculpture. But only because the baskets and edges are rounded and matched accordingly. The narrow aluminum rings create the connection between the two, and also look very valuable.

And ensure a certain visual harmony with the tweeter. In this case, the aluminum even serves to guide the sound and has a certain directional effect. This is a very good idea, because the combination of a hard 8-inch woofer and 1-inch dome tweeter is considered difficult in terms of room acoustics without such measures due to the changing dispersion behavior with frequency.

The dark silk of splendor

The tweeter itself has a new word to learn in loudspeaker technology: tetoron. This material, also known as artificial silk, is the basis of the tweeter cone. Behind it is a high-tech fiber known from textile technology, a jet-black composite material made of polyester and cotton. This combination of natural and industrial material guarantees maximum damping on the one hand and structurally stable properties on the other.

In the Nubert nuZeo 4, the separation between the two drivers is fully active at the digital DSP level. On the one hand, this offers extended possibilities when using the crossover – as can be seen from the low crossover frequency of 1.7 kHz to the tweeter, which can only be achieved with steep-edged digital filters. In addition, the DSP also offers the equalizing and app calibration options for the bass range familiar from the nuPro X series. However, the latter function requires the use of a microphone available from Nubert for Android devices. iOS users can save themselves this purchase because they can use the integrated microphone on their iPhones or iPads.

Watt full

The two amplifier channels for the woofer and tweeter produce a combined 320 watts. Permanently and with RMS signals, of course. In such power ranges, of course, classically constructed Class A/B amps are out of the question due to the heat that cannot be dissipated. However, developer Markus Pedal does not trust standard switching amplifiers with a fixed modulation frequency enough in terms of sound to hold their own in a reference series.

This is why the Nubert nuZeo 4 uses so-called PWM (Pulse Width Modulation) amplifiers. In these, the end transistors also work in switching mode, i.e. Class D. However, the instantaneous voltage is not produced via a high-frequency series of on/off processes, but via the modulated length of the pulse widths, i.e. the time span for which the end transistor “opens”. The Nubert developers trust this technology to deliver the sound of a classic power amplifier. How well the modules work is also demonstrated by the fact that the amplifier stage requires only minimal negative feedback and hardly reacts to the impedance of the drivers.

This is how the compact high-end Nubert sounds

When I fed the Nubert nuZeo 4 with the first sounds via an analog RCA connection in the smaller of the two listening rooms of the LowBeats editorial office, I was not surprised. Thanks to the strong demonstration by the development team of Markus Pedal and Thomas Bien at a press event, I was prepared for extremely powerful bass in relation to the compact dimensions and immense level reserves. In a large conference room, the smallest hi-fi speaker in the new speaker line was so powerful that I was convinced I was listening to the largest one. Both the bass, the impulsiveness and the sheer level went well beyond what one would expect from a compact loudspeaker.

So this time I was prepared for a very grown-up performance from a comparatively small speaker. However, there were still new, positive findings. With a seat relatively far back at the edge of the rows of chairs, I was unable to get an impression of the focus during my first encounter. But this time I sat in a box seat in the Sweet Sport and was amazed again – but at an extremely precise, sharply defined image. Nubert thus manages the balancing act between a certain boogie factor and the qualities that audiophiles particularly appreciate in conscious listening. The imaging precision and focus benefited considerably from angling towards the listening position.

Bass like a floorstanding speaker

But that’s not the only thing that should earn the nuZeo 4 points with discerning music lovers. The ludicrously fine and precise high-frequency resolution is also likely to delight this target group. All in all, the result was an image that was completely convincing in terms of transparency and plasticity.

As far as the bass was concerned, after the impressive demonstration of power at the premiere in the conference room, the immense punch and depth no longer came as a surprise. But what was by no means self-evident: the 2-way compact monitors cut a good figure even in a fairly small room relatively close to the rear wall. The bass sounded lush and powerful, but also offered a good degree of cleanliness under these circumstances. Although it did not tend to boom, the bass calibration via the Nubert X-Remote app had a remarkable effect. The bass gained in contour plus precision and appeared even deeper and richer by compensating for a dip and a boost between 70 and 120 Hz.

Always on the little ones

For all its splendor, the second, more intensive encounter with the Nubert nuZeo 4 also confirmed a small point of criticism. There was a slightly cool touch to the vocal reproduction. At the shorter listening distance, this peculiarity was somewhat more apparent than in the large hall. But even at the premiere presentation, this was a point that I liked a lot better in the nuZeo 15 with its 3.5-way concept. You could really tell that two of its many drivers were optimized exclusively for the mid-range and not for bass reproduction at the same time.

And I also felt the difference between a small 8-inch bass driver driven to extreme depth by the electronics of the active speaker in the best Nubert manner and an entire bass battery with four of these carbon fiber drivers. Drums simply sounded a bit more authentic with them. Given the much more obvious gap in price and the fact that many are committed to compact speakers for reasons of space alone, this could almost be seen as negligible collateral damage. For a 2-way bookshelf speaker, the nuZeo 4 certainly doesn’t need to hide from any of its competitors, especially as it looks pretty damn classy for a representative of the extremely power-driven brand from Schwäbisch Gmünd.

Verdict and alternatives to the Nubert nuZeo 4

Despite its high-end price, the new Nubert nuZeo 4 is more in the category of active loudspeakers with a built-in preamplifier and additional wireless functions. This means that it has to compete with competitors such as the Elac Navis ARB-51 and Canton Smart A45 BS. Smart Vento 3 S2 can hold their own against streaming multi-talents like the KEF LS 50 Wireless II. However, Nubert’s decision to forego direct wireless playback and integrated streaming modules in the interests of future-proofing can make things complicated and costly if these things are a personal priority. Finally, a nuControl X preamplifier for stereo applications or even a nuXinema preAV for surround systems can be found in the direct seller’s price list at 4,490 and 833 euros respectively.

Technical specifications Nubert nuZeo 4

• Manufacturer’s suggested retail price: 2,800 euros
• Dimensions (W x H x D): 24 x 43 x 36 cm
• Weight: 18.4 kg
• Special features: App, bass calibration via iPhone, removable struts with adjustable feet
• More at: www.nubert.de

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