The Voice of Authority: A Review of the Avantgarde Uno SD

The Uno SD stands as the most compact floor-standing horn loudspeaker in Avantgarde's new G3—or Generation 3—series. This latest iteration marks a significant milestone in a lineage that began with the original Uno G0 in 1995, evolving through the G1, G2, and XD series to culminate in this state-of-the-art G3-SD version. The launch of the G3 series represents the culmination of Avantgarde's latest engineering achievements. While retaining the fundamental principles of horn design, every other component has been completely re-engineered—from the drivers and crossovers to the horn architecture itself. At the heart of this evolution is the iTRON amplifier module, the technological centerpiece of the G3 platform.

From any angle, the Uno SD is a statement of aesthetic perfection. Its proportions are exquisitely balanced, while the precision of its construction and the quality of its finish speak volumes about Avantgarde's meticulous attention to detail. Our review pair, auditioned at the distributor’s showroom, featured spherical horns finished in a vibrant Genuine Red. Avantgarde offers a standard palette of twelve colors, ensuring a seamless match for any interior, and bespoke finishes are available upon request. While the eye is immediately drawn to the upper midrange and central tweeter horns, a powerful 10-inch bass driver is discreetly integrated just below.

Avantgarde offers the G3 series in two configurations: a semi-active version (powered bass only) or a fully active model featuring the integrated iTRON amplification. We auditioned the latter, which is the perfect solution for the purist who desires a simplified signal path and wishes to bypass the complexities of amplifier matching. The semi-active version, in contrast, caters to the audiophile who enjoys experimenting with their own amplifiers. Our setup for this fully active system was refreshingly minimalist: an Esoteric N-05XD Streamer/DAC paired with the G-01XD Master Clock was all that was needed to form a complete, world-class front-end.

A view of the Uno SD's rear panel reveals the elegance of its fully active design. This version, with its integrated iTRON and dedicated bass amplification, requires two separate power connections. The centrally located iTRON module is the nerve center for the midrange and tweeter horns, while the G3-500 amplifier module, positioned at the base, is dedicated to the bass driver. This G3-500 module features an active crossover that can be precisely tailored to any listening environment via Avantgarde’s proprietary software, allowing for perfect room integration.

This is the essence of the G3 concept: Avantgarde has engineered a seamlessly integrated, turnkey solution that handles all hardware complexities internally. The owner is thus freed from the endless cycle of component matching and can focus entirely on the pure enjoyment of music. In this fully active iTRON configuration, the analog output from our Esoteric N-05XD source was connected directly to the iTRON module, creating the most direct and uncompromised signal path possible.

The latest generation of the Uno SD also introduces a completely redesigned footing system, engineered for superior convenience and setup flexibility. This innovative plinth allows for precise directional adjustment (toe-in), featuring a graduated scale with 7.5-degree increments. The height is also easily adjustable, and the system includes interchangeable feet, giving the user the choice between flat discs or pointed spikes to best suit their flooring.

The construction of the base is exemplary. It is die-cast from a composite of aluminum and advanced damping materials to control unwanted resonance. The spikes themselves are precision-machined from solid metal billets, ensuring absolute stability and optimal mechanical grounding for the loudspeaker.

In any discussion of modern horn loudspeakers, Germany’s Avantgarde Acoustic is a name that commands immediate respect. Though the company has been a force since the 1980s, its founding team remains exceptionally active, relentlessly pushing the boundaries of audio engineering. New, groundbreaking technologies are consistently integrated into their products as acoustic science evolves, resulting in loudspeakers of ever-increasing refinement. Their commanding presence is a perennial highlight at the Munich High End show, a tradition we expect will continue when the event relocates to Vienna.

Thanks to the efforts of dedicated distributors worldwide, Avantgarde has achieved remarkable visibility and a stellar reputation. Over the years, factory representatives have traveled the globe to personally introduce their innovations, giving the audio community a clear understanding of the brand's progress. Today, Avantgarde Acoustic has evolved far beyond its origins in purely passive horn designs. The development of their own active amplifier modules has transformed their speakers into systems that, while physically impressive, offer a surprisingly minimalist path to extraordinary sound.

The G3 Uno SD is a perfect testament to this philosophy. As the brand's most compact floorstander, it is offered in both semi-active and fully active configurations. The latter can be equipped with the patented, fully active iTRON current-drive engine, a technology designed to deliver flawlessly controlled driver output and the ultimate in sound fidelity. The iTRON module functions as an integrated power amplifier; while it includes gain adjustment, the user simply needs to pair it with a source component with volume control or a dedicated preamplifier to create a complete, high-performance system with an absolute minimum of components.

Our review focused on the fully active G3 Uno SD configuration. We partnered it directly with an Esoteric N-05XD, an all-in-one unit that seamlessly integrates a network streamer, DAC, and preamplifier with volume control. This type of component is a synergistic match for the fully active Uno SD, and with numerous similar high-performance devices now on the market, this streamlined architecture—a smart source feeding active loudspeakers—represents a significant trend and offers a glimpse into the future of high-end audio.

For audiophiles who have already invested in their preferred amplification, Avantgarde wisely offers the semi-active G3 Uno SD. This version connects via traditional speaker cables, just like a passive loudspeaker. The speaker's internal crossover automatically delegates the bass frequencies to the built-in G3-500 amplifier module. By self-powering the demanding low-frequency section, the speaker presents a very benign load to the external amplifier, making the midrange and tweeter horns exceptionally easy to drive.

Furthermore, the active bass module is equipped with a powerful DSP engine. This allows the user to precisely tailor the low-frequency response using Avantgarde’s proprietary software for perfect room integration. The system offers granular control over numerous parameters, including gain across different frequency bands, roll-off slopes, and time delay. The goal is to achieve the most accurate and seamless bass imaginable in any listening space. For those who prefer a hands-off approach, authorized dealers provide a complete professional calibration, including in-room acoustic measurements, as part of the installation service.

Turning to the listening session, we began with the iconic audiophile recording, Proprius’s Cantate Domino. Through the fully active G3 Uno SD, the sound had exceptional projection, cohesion, and solidity. There was an unmistakable sense that the drivers were being perfectly energized, performing with an effortless authority that is independent of volume level. It’s a palpable sensation of power, focus, and absolute control. The grand scale of the choir was rendered with breathtaking realism, its presence at once serenely gentle and powerfully solid. Waves of organ bass rolled into the room, yet each note was defined with impeccable speed and clarity. This is the inherent advantage of a perfectly synergistic, active design, where amplifiers and drivers are in absolute harmony. Beyond the spatial benefits, this profound integration is the greatest triumph of the active loudspeaker—an advantage the G3 Uno SD expands even further with its DSP-controlled bass.

What is truly remarkable, and perhaps the highest concern for any discerning audiophile, is the ultimate sound quality. The G3 Uno SD delivers a profoundly silent background. This is a critical achievement for a horn loudspeaker of such high sensitivity, where any trace of noise in the signal path would be instantly exposed. Instead, the backdrop to the music was utterly black and serene, allowing the sound to emerge with exceptional purity and cleanliness, free from any electronic grain. The famed silent passages in Cantate Domino were rendered with the stillness of a vast cathedral, where one could hear a pin drop.

Furthermore, the music never felt constrained in its frequency range. The high and low-frequency extensions were seamless, without any sense of an artificial boundary or abrupt cutoff. Instead, the notes tapered off naturally, decaying into the silent background. It is clear that Avantgarde Acoustic has invested immense dedication and engineering prowess into this new generation, and the magnificent results speak for themselves.

For this review, our focus is on the Avantgarde UNO SD horn loudspeaker. Having previously spent time with its larger sibling, the DUO SD, we noted the strong family resemblance in their design; the UNO SD, however, presents a discernibly more compact footprint.

We began our listening with Ed Sheeran's "Photograph," a familiar track to gauge the speaker's vocal performance. The presentation was immediately captivating. Sheeran's voice was rendered with a singular intimacy and vivid clarity, creating the distinct sensation of the artist performing just a few feet away. A holographically focused image formed directly before us, yet from this precise point, the music unfolded to fill the space with an impeccably broad and balanced soundscape. This created a powerful duality: the arresting image of the singer performing live, combined with the deeply satisfying, immersive feeling of being completely enveloped by the performance.

This level of resolution revealed a richer contrast in the vocal nuances. Notes sung in full voice were rendered with palpable weight and a commanding presence, while Sheeran's falsetto passages were conveyed as pure and gentle, appearing to emanate from slightly deeper in the soundstage, which in turn created a more profound sense of layering.

The drumming demonstrated superb dynamic articulation, from the deepest impacts to the lightest taps. When the vocals and percussion played in unison, each maintained a distinct and appropriate space within the mix. The drum lines were stable, full-bodied, and weighty, yet they never once intruded upon the delicate, clean vocals. It was a masterful balance of power and finesse: the propulsive rhythm against the serene vocal, the percussive weight against the lyrical lightness. This allowed the song's dynamics to feel wonderfully agile and luminous, restoring the track's intended atmosphere of peace and warmth.

We then turned to Eric Clapton's classic, "Wonderful Tonight," where the UNO SD's handling of instruments proved to be stellar. The cymbals were rendered with a nimble touch; even during rapid, rhythmic strikes, they maintained a crisp, articulate character. Though appearing repeatedly in the track, each hit was a fleeting shimmer—decaying instantly—while still fully conveying the clean, metallic texture of the brass. Positioned at the far edges of the soundstage, these details were exceptionally lively and distinct, giving the entire presentation a beautiful sonic gloss.

The drum hits, by contrast, were delivered with a dramatic tension that seemed to leap from the speakers at the moment of impact. While the presentation may have prioritized this explosive agility over the final degree of foundational weight and authority, the sound was uniquely captivating. The speakers rendered the instruments in a manner that was unexaggerated yet exceptionally vivid and natural, breathing new life into this timeless recording.

The guitar work was a particular highlight, rendered with superb elasticity. The clean, clear timbre was a given, but it was the phrasing that captivated; each melodic line traced elegant, flowing arcs through the air. The notes seemed to dance and weave within the soundscape with a vibrant energy, soaring with detail and extension yet remaining completely free of sharpness or etch. It was a sound that was emotionally resonant without a hint of stridency.

This seamless coherence extended to all the instruments. Even within the enveloping presence of the drums, the crystalline guitar notes were perfectly integrated, contributing to a holistic and beautifully resolved sonic tapestry.

Clapton’s voice, in turn, was presented with a wonderful freshness and vitality, rich with nuance and natural ease. The subtle emotion in his relaxed delivery emerged effortlessly, drawing the listener into a performance that was both profoundly intimate and utterly comfortable.

For our last reference, we played "Every Breath You Take" by The Police, and I was thoroughly impressed by the UNO SD's presentation of the drums. Each beat landed with an immense solidity, but what was truly special was the resonance that followed—a rich, full-bodied bloom that emerged from deep within the soundstage. It spread out with a profound, sonorous color, painting a dark, foundational wash across the track's background that anchored the entire performance.

Yet, for all this authoritative weight, the rhythmic punctuation remained exceptionally taut and full of tension. The playing was brimming with dynamic energy, and the essential elasticity of the drumming was preserved without compromise. Paired with the other instruments, this masterful handling of the track's rich contrasts made for an absolutely thrilling and gratifying listening experience.

The iconic guitar and bass lines were conveyed with that same excellent elasticity. The timbre was rich and full-bodied, with each note rendered as perfectly rounded and lustrous as a pearl. Possessing both agility and grace, these melodic elements worked in concert with the drums, creating a masterful interplay between rhythmic bounce and foundational weight that pushed the dynamic contrasts in the music to their fullest expression.

Listening through the UNO SD was a particularly immersive experience. The music filled the room with an effortless, majestic scale, placing the listener directly inside the performance and allowing every detail and strength of the recording to be felt more profoundly.

Sting's vocals were projected with a stunning, front-row immediacy. Every subtle breath, every shift in intonation, every silky phrase and nuance of his clean timbre—all of it was revealed with uncompromising transparency. From the seething energy of the track’s climax to the calm stability of its quieter moments, the speakers kept us perfectly in sync with the melody, creating a truly transportive experience that pulled us headfirst into the heart of the music.