Avantgarde Acoustic Duo SD Horn Speaker Review image

Avantgarde Acoustic Duo SD Horn Speaker Review

Avantgarde Acoustic started with horn speakers 30 years ago and has since become famous and sold in over 60 countries. They continue to improve and innovate while remaining loyal to horn speakers, combining the oldest form of sound amplification with modern technology to create works combining elements such as tradition, craftsmanship, and technology.

Their mission is to reproduce the most moving musical art perfectly. Avantgarde Acoustic has constantly innovated and undergone two significant breakthroughs in the past 30 years. In 2021, they completely renovated their products to the third-generation design, represented by the “G3” in the product model. The Duo introduced here has two models, Duo GT and Duo SD, which are newly designed third-generation products.

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The Duo series has been reduced to two models compared to the previous Duo XD. The Duo GT is the high-end model, while the Duo SD is the entry-level model. The main differences between the two models are the number and size of the bass drivers, as well as the size and structure of the cabinets.

In simple terms, they are suitable for different spaces, but there is little difference in technology and design. The photos show that the Duo SD has a refined appearance, with the midrange driver and horn located on the main cabinet, and the side and top of the cabinet are treated with glass paint. The front is mainly woven mesh, except for the horn section.

The back of the cabinet is where the mystery lies and the base is also different from the past, with four improved floor cones that are easier to adjust in height and more concise than before.

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The most significant new design of the Avantgarde Acoustic third generation, apart from the renovation of the unit, is the new active planning, which we will start discussing here. Not only Duo SD but the first concept of the entire series is the choice between fully active and semi-active designs.

The basic version is a semi-active design, which means that the low-frequency part is happening, and the high and medium frequencies are passive. Another version is fully active, meaning all high, medium, and low frequencies are involved. The fully active version can also be purchased with a switch, which can switch between the two modes at will.

The version displayed at the current audio exhibition can be switched between semi-active or fully active. You can see that all modules have been installed, and there are still input terminals for connecting speaker wires. In the photo, you can see three modules in total: the top one is the input terminal for the mid-high speaker, which contains the latest G3 version of the frequency divider, using spherical wave low-pass filtering technology, AirGate sound filtering chamber, brand new NatureCap capacitor, and third-generation PolarisationPlus circuit.

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The center is the iTRON active power module, which includes current direct drive technology, a symmetrical single-ended circuit without any negative feedback, and can directly control the diaphragm acceleration, perfectly controlling the diaphragm operation.

The bottom is the G3-600 low-frequency power module, which includes 500 watts of power output capability, processor-controlled active filtering, and an editable new adjustment interface.

The composition of a horn speaker consists of two main components: the familiar driver and the horn. Due to the ability of the horn to focus sound waves and achieve high-efficiency sound pressure regeneration, compared to non-horn speakers, it can reduce the displacement intensity of the driver diaphragm during operation.

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That not only reduces the distortion caused by diaphragm movement but also reduces the demand for amplifier power. Although high-power amplifiers are now very common, non-horn speakers require more power, which can cause problems such as coil temperature, resistance increase, and lower efficiency, resulting in more distortion.

Therefore, the advantages of horn speakers still make them occupy a place in modern speakers. However, the design of the horn itself also poses a serious challenge to every designer. When the diaphragm drives the air and transmits it to space through these horns, the horn also affects sound characteristics such as tone, frequency, directivity, and distortion.

Therefore, the material, depth, curvature, angle, and opening size of the horn are all details that need to be considered. Avantgarde Acoustic has 30 years of continuous research on this and is now at the top of the market with its horn technology, which can provide eight times the dynamics of ordinary speakers, reduce 90% of distortion, and provide ten times the resolution.

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The Duo SD midrange speaker uses the latest XM2 technology, which includes the new XM2 Duo Evolution driver, 18-ohm Omega technology, a 170mm diaphragm, and a circular horn with a 670mm aperture, resulting in an overall efficiency of 107dB. It is responsible for frequencies between 170Hz and 3,500Hz.

Duo SD high-frequency uses the latest XT3 flagship high-frequency, with a 200mm high-frequency horn opening size and a 176mm long horn depth. It has an XT3 Duo Evolution unit, a 25mm annular diaphragm, and a dual-layer suspension system. The frequency extension can reach 28,000Hz.

A brand new 12″ XB12 woofer with a 152mm wide, 480mm long, 1.15 Tesla magnetic flux density voice coil is located below the high-frequency driver in the woven mesh. The Duo SD woofer is not a horn-type design and uses a long fiber paper and carbon fiber composite diaphragm to handle the 18Hz~350Hz frequency range.

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The Duo SD can adjust and modify the low-frequency response curve through its software, an essential function that can help it adapt to each user’s environment. When users do not know how to adjust, they can even send data back to the factory through the reception method, and the factory can change the appropriate settings and apply them directly to the home system. If your space is large, you can also choose the Duo GT, a product from the same series with two XB12 woofers, to get even stronger bass.

In the new third-generation speakers of the G3, active bass can be directly adjusted through the latest computer software provided by Avantgarde Acoustic, including changes in sound pressure levels in different frequency bands, which can smooth out or fill in excess or lack of sound pressure in various frequency bands caused by the listening environment and can also create the desired playback effect. If users need to become more familiar with the software, agents, dealers, and even the manufacturer can provide adjustments.

Sound Performance

Details are one of our favorite expressions when listening to music, especially when we are excited to hear what we are familiar with in the music. That is also one of the reasons why live recorded music is famous. Of course, the live and different changes are also. The details and micro-dynamics exhibited by Duo SD when playing Diana Krall’s “Live In Paris” are vibrant.

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Many people are in the most relaxed state of mind and body when listening to jazz music, usually not pursuing high volume or even just listening to background music. However, live jazz music has many subtle sounds that attract us. Avantgarde Acoustic’s horn speaker may be the best choice if you want to demonstrate it at low volume fully.

Duo SD’s performance in detail, micro-dynamics, resolution, and contrast is first-class. Compared with the old model, in our impression, the new Duo SD has a smoother connection in the frequency band and more consistent cooperation between the units.

Not only in this type of music, but also in music closer to classical types such as violin and piano, Duo SD’s horn speakers can bring listeners more delicate, crystal-clear, direct, and abundant energy, and rich and magnificent sound performance.

Since active bass is being used, it is inevitable to test the low-frequency performance. The tracks in “Touch Yello” have rich and fast mid and low-frequency performances and even demonstrate different low-frequency types to test the sound system’s persuasiveness.

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The low-frequency performance presented in this space is agile, flexible, abundant, and comfortable, with each rhythm point starting with power and impact and ending cleanly and transparently. It is consistent with the connection of the mid-frequency.

Continuing to try “The World Of Hans Zimmer” movie soundtrack album, the overall grandeur and completeness of the dynamics and details are more evident in larger orchestral music, with the powerful and direct sound and a soaring momentum, yet delicate, smooth sound quality.

First, referring to Bonnie Raitt’s rendition of the song “Something’s Got A Hold Of My Heart,” it is effortless to notice that the vocals are clear and clean. With the ability of these speakers, the volume does not need to be turned up very loud to hear Bonnie Raitt’s delicate and exquisite performance, giving a sense of being present at the live performance.

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The sound is very neutral and detailed as the music plays, with every detail being very clear. The sound quality is excellent in terms of detail resolution. In addition, the sound is also round, smooth, full, rich, and warm, providing a comfortable and satisfying auditory experience.

The bass part is also unique, profound, and elastic, with great resonance. The vibration of the air is enjoyable, and with the resonance, the sound is thick and weighty, giving a sense of cohesion. At the end of the track, there is a feeling of vibrant music filling the entire room.

Following that, referring to John Legend’s “All Of Me” the piano sound played at the beginning, and the flavor of the piano sound was evident from the start. The rich flavor was set against an excellent and bright piano sound, allowing the piano sound to exhibit a fuller and richer feeling. The human voice was also very cohesive. In addition to being complete and thick, it could also be felt as a powerful and weighty voice that cannot be ignored.

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Listening to it, one can feel the beautiful and detailed voice performance, as if the sound is directly injected into the ears, with a very realistic sense of presence, resulting in a considerable improvement in the emotional rendering ability of the song. It feels as if the whole space is filled with a faintly sad singing voice.

The picture displayed by the music also feels broad, expanding or contracting with the sound’s grandeur or slowness. Especially when John Legend’s voice pushes the climax of the music to its peak before the song’s end, the picture in front of you ultimately expands without any restrictions, and the whole person seems to be enveloped in the romantic sadness of the music.


the Avantgarde Acoustic Duo SD Horn Speaker is a remarkable piece of audio equipment that offers unparalleled sound quality and design. The horn-loaded drivers provide incredible detail and clarity across the entire frequency range, while the sleek and minimalist design adds a touch of sophistication to any room. The ability to customize the color and finish of the speaker also makes it a versatile option for a variety of interior design styles.

While the Duo SD Horn Speaker is certainly an investment, its exceptional performance and aesthetic appeal make it a top choice for discerning audiophiles and design enthusiasts alike.