DUO SD Reduction does not always mean simply doing without. Reduction often means focusing on the essentials. Or simply: concentration. The DUO SD, with its single-drive bass unit, is the essence of what makes a speaker – the perfect introduction to the ‘classic sound’ of the DUO range.
DUO SD THE NEW ENTRY INTO THE WORLD OF DUO SOUND. Driven by its impressive 670 mm spherical wave horn with a frequency response up to 170 Hz, the DUO is the epitome of performance and dynamic elegance. In the fascinating world of spherical wave horns, size is the defining criterion. The larger the horn, the deeper its lower bandwidth and the more the listener is drawn into the maelstrom of superior performance. The Evolution XM2 midrange driver – a 170 mm chassis with a powerful Alnico magnet – is designed for a large linear diaphragm excursion. Its new ‘Soft Mesh Compound’ cone uses a robust mesh shell as the basis of its construction. The microscopic openings in the mesh are sealed with a damping elastomer coating. The combination of the strong mesh structure and the flexible coating creates a broadband absorption effect that effectively dampens partial vibrations of the diaphragm and thus unwanted harmonics. The DUO SD uses the same XT3 tweeter as our flagship TRIO G3. The XT3’s lighter, annular diaphragm extends the frequency range up to 28,000 Hz with a sensitivity of 107dB/W/m, providing greater clarity, focus and a fuller, more natural sound. The subwoofer uses the new high-performance XB12 driver in a bass-reflex configuration. We increased the voice coil diameter from 100mm to 153mm and this huge 6-inch motor structure achieves superior power factor and power handling. At the same time, thermal compression is significantly reduced. The G3-500 bass amplifier delivers 500 watts and features an advanced digital sound processor. The new user interface makes it easy to adjust the sound to suit individual preferences and to integrate the system seamlessly into a wide variety of rooms. 1234
In the G3 Series, we have taken the bionic horn principle to the extreme. Highly bred horn performance through unrestrained efficiency with a huge transmission range.
New Evolution driver generation for enhanced dynamics and purer sound.
Innovative XT3 tweeter with new long-throw horn and extended supertweeter frequency range with record-low distortion levels.
New improved XM2 DUO Evolution driver with 107dB efficiency and 18 Ohm Omega technology.
One 12″ XB12 driver with 153mm voice coil and 1.15 Tesla flux density over 480mm voice coil length. Diaphragm composite of long fibre paper and carbon fibre.
New elegant color and design options for an even more customized configuration of your dream speaker.
In the G3 Series, all drivers are on one axis. This means that the acoustic centers are all on the same plane. The distance of the acoustic centers of the drivers to the listener are therefore always identical. Accordingly, the signals from the respective sources (tweeter, midrange and woofer) arrive at the same time and thus correctly.
All the electronics are housed in easily replaceable technology modules. So that you can easily expand or upgrade your system even after many years.
Patented iTRON current fully active engine for perfect control of membrane vibrations and the ultimate sound.
Integrated power amplifier with 500 watts of amplification power and processor-controlled active filters. New G3 user interface for programming.
One speaker. Two versions. SEMI-ACTIVE VERSION. The semi-active version is designed to be used with external hi-fi amplifiers. With an efficiency of 107dB/W/m and an impedance of 18 ohms, the speaker is extremely easy to operate and ideal for low-power amplifiers. The ideal speaker for the world’s finest high-end amplifiers. iTRON VERSION. In the iTRON version, the amplifiers are built into the speaker, eliminating the need for external power amplifiers. To achieve this, we have developed an electronic system that is based on a fundamentally different operating principle to any of the conventional amplifiers on the market. We are the first manufacturer in the world to achieve what was previously thought to be an impossible technological feat. For a sound that is simply heavenly. 12
Modular technology for versatility & timelessness. Each model has a replaceable technology module that connects to the loudspeaker via a multi-pin power connector. This makes it easy to upgrade the semi-active speaker with iTRON technology at a later date. It can be upgraded to the most advanced digital technology available at the time, even after many years. This ensures the sustainability of your investment for generations to come.
Coplanar alignment of the drivers. In the speaker, all the drivers are on the same axis. This means that the acoustic centres are all in the same plane. The distance between the acoustic centres of the drivers and the listener is therefore always identical.
Driver technology
We have spent over five years refining, experimenting, improving, measuring, and listening to the new G3 Evolution driver series. The horn and driver have been so perfectly matched that the Evolution Series is a sound-coherent unit of superior quality.
We have been working exclusively and intensively with horn technology for over 30 years.
This has given our company a unique wealth of experience and enabled many fundamental innovations.
We use only the best materials. We follow the principles of German quality engineering in development and production.
The perfect crossover. With our SphericLowCut filter, Airgate technology and PolarizationPlus circuit, we have developed the most innovative technological concepts in our passive crossover. These are completed with the highest quality components available. Our new NatureCap is an extremely complex capacitor, handmade in Germany. The electrodes are made from precision-rolled aluminium foil, rather than ultra-thin plastic film vaporized with aluminium. The dielectric is a cellulose fibre compound impregnated with organic oils. The NatureCap is approximately 25 times larger than the previous XD series capacitors and is securely mounted to the circuit board using specially manufactured brackets. 12
XB12 bass driver RADICAL BASS. RADICAL DRIVE. For the DUO SD we have developed a completely new drive. Compared to the previous model, we have increased the voice coil from 100mm to 153mm. With this gigantic 6 inch motor structure we achieve absolute top values for the power factor and the power handling, while reducing the power compression. The motor structure consists of two High Grade magnets magnetised in Europe’s largest 200,000-volt facility. The huge voice coil transfers the power of the permanent magnet with 1.15 Tesla flux density to a voice coil circumference of 480mm. This is an increase of over 50% compared to the previous model! We use low carbon steel for the pole plates, which are specially designed for the XB12. To ensure high linearity even at maximum diaphragm excursion, the spider has a patented dynamic profile with a progressive surround design. The surround is made of low-loss NBR (Acrylonitrile Butadiene Rubber) for fast and clean transient response. The diaphragm is made from a composite of long-fibre paper and carbon fibre – extremely strong and torsion resistant for precise pistonic excursion of the diaphragm during transients and decay. The XB12’s new SingleFrame chassis features robust die-cast aluminium cantilevers, which also enclose the magnet, providing a totally rigid material bond around the moving parts of the motor structure. The XB12 is our reference in terms of bass. A statement that underlines the uncompromising and unique nature of the G3 Series. 1234
Bass amplifier STRENGTH IN ALL SITUATIONS. The DUO SD’s active subwoofer is powered by the G3-500 power module. This integrated power amplifier consists of a 500-watt amplifier that provides ample headroom for complex EQ settings. The subwoofer can be switched on remotely via a 12-volt switching input. Direct connection to integrated amplifiers, power amplifiers or receivers is via speaker-level input terminals. Alternatively, line level inputs are available via XLR connectors. The signal tap is not only high impedance, but also balanced and transformer-coupled. This keeps the circuit ground floating, eliminating hum and making it easy to connect to balanced and bridged amplifier designs. All electronics are fused via a state-of-the-art E-Fuse circuit. Not only is this much faster and safer than conventional fuses, but it is also ideal in terms of sound. 12
Digital crossover. EVERYTHING UNDER CONTROL. The bass power amplifier is equipped with an advanced digital sound processor. The digital crossover eliminates all passive filter elements in the signal path with a precision and bit accuracy that cannot be achieved with analogue technology. The volume of the subwoofer can be adjusted using the two buttons on the DSP display. The Avantgarde Control Software allows a wide range of additional settings (e.g. high and low pass filters, equalisers, etc.) to be programmed. The DSP has 2 x LAN sockets, allowing multiple subwoofers to be daisy-chained for simultaneous programming. A USB connection is optionally available. The user interface has been completely redesigned and is now very easy and intuitive to use. All parameters can be easily adjusted to suit the room acoustics or listening habits. The BASS-BOOST control can be used to boost the low-frequency response below 45 Hz, allowing the bass response to be adjusted from ‘linear’ to ‘rich’. The DSP has an 8-band equaliser for individual frequency adjustment. Each of the 8 bands can be raised or reduced by up to 4 dB. This can be used to adjust the bass response to suit a particular sound (linear, techno, pop, rock, classical, etc.) or to reduce certain broadband room resonances. The LPF-RANGE slider adjusts the upper crossover frequency of the subwoofer and thus the “tonal balance” of the system. At higher frequency settings, the subwoofer partially overlaps with the midrange horn’s frequency response. This makes vocals/instruments sound ‘warmer’ and ‘fuller’. When the crossover frequency is set lower, there is a small gap between the subwoofer and midrange frequency response. The tonal balance of the system shifts towards a more ‘dynamic & punchy’ sound. FILTER 1 & 2 are narrow band ‘notch’ filters with a level cut of -3dB or -6dB. These filters can be used to eliminate/reduce unwanted narrowband room resonance frequencies. 12345
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Blending horn-speed with articulate mids and surprisingly supple bass, the DUO SD delivers a big, polished presentation that stays composed when properly set up. Matthias Böde praised its efficiency and room-filling clarity, while Audiophilepure highlighted superb realism, bass definition, and room-correcting DSP finesse.
Exceptional clarity and realism, with articulate, harmonically rich mids that make jazz and vocals sound especially convincing.
Strong bass definition and presence, with room tuning helping the low end integrate cleanly with the rest of the spectrum.
Excellent imaging stability and depth, with controlled horn dispersion that can reduce room-induced haze.
Highly efficient, delivering big sound with very little amplifier power and strong composure at normal listening levels.
&
Cons
Can sound hard, shouty, or compressed when pushed too loudly, so it rewards sensible volume levels.
The sweet spot is relatively narrow, so precise placement matters for the best imaging.
SOUND QUALITY PERFORMANCE 95/100
Reviewers describe a very accomplished, highly resolving sound with strong tonal color and a presentation that stays composed even when the music gets busy. The Duo SD is repeatedly praised for doing some things extraordinarily well, with room-related caveats rather than speaker-related weaknesses.
Bass
95/100
Bass is praised for clarity, definition, and presence, with one reviewer noting that a small amount of added bass produced excellent results on both jazz and classic rock. The large subwoofer section and the comments about Chris Squire's bass lines suggest real authority and control rather than just quantity.
Mid
96/100
The midrange is described as articulate, harmonically dense, and complex, which points to very strong timbral realism. On the earlier review, horns, piano, percussion, and bass in small jazz combos were said to be spot-on, reinforcing a natural and convincing middle band.
Treble
93/100
Treble is not described as edgy or harsh; instead, the speaker is said to direct less room-excited ambience into the listening space, with horn behavior helping keep the mid and treble controlled. The reviews give less explicit language about sparkle or air than about the rest of the range, but the overall impression is of a refined top end.
Soundstage Imaging
94/100
Imaging is reported as strong, with good image depth and transparency, fairly good focus, and very good stability that was notably unaffected by sound level. The controlled horn dispersion also seems to help it behave consistently at the listening position, especially in difficult rooms.
Dynamics
96/100
The speaker comes across as effortless and scale-friendly, with excellent composure at higher levels and no sense of strain in the descriptions. Reviewers say it did everything well and handled sound level changes without losing image stability, which points to very confident dynamic performance.
Assessments of Build Quality, Usability, and Overall Propositions.
Build Quality
92/100
Reviewers do not dwell on cosmetics or cabinet workmanship, but the product's execution clearly supports a complex, high-end active design. The comments about room correction, controlled horn behavior, and the ability to perform consistently at different levels suggest a serious, well-engineered loudspeaker rather than a showpiece with no practical substance.
Value for Money
85/100
The reviews do not really engage in direct price-versus-performance commentary, and there is no explicit praise or criticism of value in relation to the asking price. One review calls the speakers truly excellent and says the listener would be perfectly satisfied with them long term, but that is a statement about satisfaction, not a direct judgment on value.