Nuberts nuZeo 4 Review
Quite large for compact active speakers and weighing over 18 kg each, Nuberts nuZeo 4, aims to shake up the absolute top class.
The company Nubert was founded by Günther Nubert in 1973, based on his parents’ furniture factory, and is now one of the leading speaker providers in the German-speaking world. Sales are primarily direct, but Nubert speakers are also available in their own stores and, more recently, through retailers.
Nubert has a long tradition of active speakers, with early generations geared toward professional studio technology. As a result, they showed very little noise. Despite this, the well-sounding types like the nuPro series were relatively affordable.
Pro in High-End
With nuZeo, the Swabians now aim to enter the high-end active speaker market. The pair of compact nuZeo 4 speakers. According to Nubert, these speakers, available in black or white, belong to the “absolute top class” and are here to make waves. The nuZeo models are pure, high-quality active speakers without any extra features like streaming.
Let’s take a closer look at the technology. The standout feature is the unusual woofer. For compact speakers, the 8-inch, or 20 cm diameter, is impressive. The surrounds, sometimes humorously referred to as “thick lips,” are rare in home Hi-Fi full-range speakers but more common in car subwoofers. Such surrounds offer stability and allow for high displacement, contributing to dynamic and powerful sound.
But the suspension isn’t the only unconventional aspect of Nubert’s custom-developed driver. The membrane isn’t a cone but a concave “half-sphere,” more like an inverted dome. The double-layered carbon membrane, coated with a transparent polymer damping layer, is made in one piece, omitting the usual dust cap over the voice coil.
This design is meant to ensure rigidity in the lower frequencies and freedom from partial vibrations in the upper range, enhancing clarity, particularly in midrange and vocal reproduction. The powerful motor system, combined with the bass reflex principle and DSP with a linearized bass response, allows the speaker to deliver both “punch” and precision in the lower ranges. Nubert claims a deep bass extension of around 30 Hz, surpassing many floor-standing speakers.
The 26-mm tweeter, housed “behind bars,” is another Swabian creation. Its artificial silk (Tetoron) membrane offers slightly better resolution in the highest frequencies compared to natural silk. A precisely tuned, acoustically dampened rear chamber behind the tweeter minimizes resonance and allows for a low crossover point of 1,700 Hz to the woofer. This enhances both vertical and horizontal dispersion and reduces interference in the crucial crossover range. They also used a slight diffuse field equalization, a common microphone technique.
Looking at the overall frequency response, which extends into the infrasonic range below 20 Hz, it becomes clear that the DSP doesn’t filter these frequencies sharply, leading to unnecessary membrane movement below the audible range. This strains both the amplifier and the driver unnecessarily.
Unfortunately, this small – and in our opinion, easily fixable – flaw results in relatively high distortion. The DSP seems to “wake up” again below 20 Hz. We believe this was simply overlooked in pursuit of deep bass, but it could easily be corrected with a firmware update.
WHAT WE LISTENED TO
TORI AMOS: “LITTLE EARTHQUAKES”
Expressive, sensitive singer at the piano.
FLIM & THE BB’S: “TRICYCLE”
A legendary test track and a benchmark for any system. Top-notch bass and dynamics.
TEST EQUIPMENT
CD Player: Audiolab 8300 CDQ
Streamer/DAC: Audiolab 6000N
Preamplifier: Nubert nuControl, Vincent SA-T7D
Cables: HMS, Supra
An App for More
The “Nubert X Remote App,” available for Android and iOS, allows individual room calibration for some of their products, including subwoofers and active speakers. It’s one of the simplest optimizations imaginable. The app uses either the powerful built-in microphone of Apple iPhones or, for Android users, requires an optional measurement microphone due to the wide variety of Android devices. Nubert wanted to ensure reliable and consistent results. Stereo has tested the app multiple times and can attest to its high accuracy and great usability. Additional features include sound adjustments and automatic power on/off for the speakers.
Whether connected via cables (we preferred XLR) or wirelessly using the house’s new nuControl-X preamp or the external wireless adapter nuConnect trX, the Nubert nuZeo 4 never falters. They sound lively, open, and natural, with a sense of size and maturity thanks to their design.
Their bass is sturdy and substantial, yet rhythmic and effortlessly agile. We put the nuZeo 4 to the test with “TriCycle” by Flim & the BBs, a dynamic challenge with killer potential. Even the finest details are resolved effortlessly, with dynamic shading, and impulse response is instantaneous in the room. The achievable maximum volumes are quite impressive, where other speakers might struggle. Simply outstanding!
By the way, these gems are naturally great for home theater too, though they lack Toslink and HDMI. For many music fans, these “compact all-rounders” may settle the speaker debate, though they might still be curious about the larger models. Welcome to the top class!
Specs
| Product / Price Class | Active speakers / 2,000 to 4,000 euros |
| Dimensions (W x H x D, in cm) | 34 x 47.7 x 43.4 (with stands) |
| Weight (in kg) | 18.4 |
| Distribution in Germany | Nubert |
| Principle | Dynamic, 2-way, bass reflex |
| Communication Between Speakers | Wireless / wired |
| Recommended Setup Info | Free on stands, slightly angled |
Verdict
| Category | Weight | Rating | Remarks |
| Sound Quality | 45% | 8.3 | Neutral, lively, natural, dynamic, robust |
| Measurements | 10% | 8.3 | Good frequency and impulse response, low distortion |
| Features | 15% | 5.7 | Calibration via app, black/white finishes, good build |
| Handling and Operation | 20% | 5.5 | Easy setup, good display operation, excellent manual |
| Service and Environment | 10% | 5.3 | 2-year warranty, plastic/cardboard packaging |
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