Floorstanding loudspeakers — Avantgarde Acoustic UNO SD

The UNO SD is a horn loudspeaker with a powered bass section from Avantgarde Acoustic, a German manufacturer of large horn-loaded designs that pair very high efficiency with built-in amplification. It is a more compact entry point into Avantgarde's horn range than the brand's largest models.

Key specs that matter

Rated response of the horn section is 290Hz to 22,000Hz within plus or minus 3dB. Sensitivity is 107dB and impedance is 18 ohms. The recommended external amplifier power for the horns is only 10-50W, while a built-in 500W amplifier drives the powered bass module. The speaker measures 50.0 x 135.5 x 61.5cm and weighs 81.5kg, much of it in the internal amplification and bass driver hardware below the horns.

Engineering and use context

The horns cover only the midrange and treble, which is why the rated lower limit sits as high as 290Hz. Low frequencies come from the built-in powered subwoofer section rather than from the horns themselves. Horn loading gives far higher efficiency than conventional cone drivers, so even a modest amplifier drives the UNO SD to high volume.

Pairing

The low power needs of the horn section make the UNO SD a match for low-power valve amplifiers, single-ended triode designs included. The internal bass amplifier covers the low frequencies on its own, whatever external amplifier is used.

Alternatives

The Avantgarde Acoustic Duo SD is a larger horn system from the brand, at considerably greater scale and price.