Floorstanding loudspeakers — Aequo Audio Stilla

The Stilla is a floorstanding loudspeaker from the Dutch company Aequo Audio, hand-built with a curved enclosure. It is an active hybrid design - the upper range runs from an external amplifier, while built-in powered subwoofers look after the low end. In the Aequo range it sits below the Ensis, which the maker describes as the more capable model.

Key specs that matter

Two 179 mm (7 inch) subwoofers are fitted to every cabinet, each fed by its own 250 W Ncore amplifier. A mid-bass driver with a mineral-filled polypropylene cone and a hexagonal voice coil sits above them, and the treble comes from Aequo's F40 high-frequency transducer. Aequo lists a range of 14 Hz to 35,000 Hz, a sensitivity of 90 dB and a nominal impedance of 8 ohm. The cabinet is 107 x 16 x 26 cm and weighs 21 kg.

Engineering and use context

The two subwoofers are placed at opposing 45 degree angles so their sideways forces cancel, which keeps the narrow cabinet from being shaken by its own bass drivers. A tapered cavity runs the full length of the lower subwoofer cabinet and ends in a horn-loaded output, making the system a horn-loaded bass reflex that Aequo measured to 18 Hz at -3 dB in a room. The F40 tweeter has a concentric fabric ring and an aluminium dispersion cone on a carbon fibre rod, and acts as an acoustic lens intended to widen the listening area. The enclosure combines Scandinavian plywood, HDF, a high-stiffness artificial stone formed under heat and pressure, and CNC-machined aerospace-grade aluminium, with high-density sheep wool as the absorbing material. Low-frequency output is adjusted steplessly through the ARPEC bass-control system, which works with a DSP. With a front only 16 cm wide, the Stilla suits a 20 m2 room where bulky boxes would dominate. The materials used for the enclosure were developed by Aequo in-house.

Pairing

With the subwoofers self-powered, the partnering amplifier is left with just the mid-bass cone and the F40. Aequo states the load suits any amplifier rated for 2 to 8 ohm, so modest integrated amplifiers and valve designs are both workable, and each speaker also needs a mains connection for its internal Ncore modules.

Alternatives

The Aequo Audio Ensis is the brand's larger floorstanding model for buyers who want more capability than the Stilla.