Напольная акустика — Apertura Audio STELA

The Stela is a compact tower from Christian Yvon's Apertura, built by hand near Nantes in western France. It completes Apertura's range of three compact speakers alongside the Swing and Sensa, with the same design principles but greater bass and dynamic capability from a 2-way, 3-driver layout. It was shown at the Munich High End show in a metallic green version.

Key specs that matter

It uses two 16 cm Seas bass-midrange drivers and a 25 mm Ring Radiator tweeter. The cabinet is bass reflex with a rear vent tube. Frequency response is 40 Hz to 30 kHz, sensitivity is 88 dB at 2.83 V and nominal impedance is 8 ohms, with a 6 ohm minimum. The speaker measures 230 mm wide, 310 mm deep and 970 mm high and weighs 19 kg.

Engineering and use context

Two bass-midrange drivers usually halve impedance, but Apertura uses a special version of the woofers so the Stela keeps an 8 ohm nominal load and places less strain on the amplifier. The cones use isotactic matrix technology, a composite of woven coated polypropylene tapes with good linearity and damping. The magnet circuit concentrates flux on a 26 mm voice coil, the coil is ventilated to avoid compression between the phase plug and pole piece, and the rubber surround has radial reinforcements to limit break-up at long excursion. The Ring Radiator tweeter extends beyond 30 kHz with controlled directivity, and its magnet system uses double ferrite for higher sensitivity and lower distortion. The cabinet is 18 mm MDF with four internal bracing panels that stiffen the structure and create cavities for damping, and four different damping materials treat standing waves. A base plate provides stability and four adjustable spikes allow fine positioning. As in Apertura's larger models, crossover values are adjusted to the measurements of each individual set of drivers. The filter uses the DRIM topology with successive slopes of 6, 12 and 24 dB per octave, is hand-built on a printed circuit with thick 140 micron tracks and uses polypropylene capacitors and wirewound resistors, with a crossover point of 3.4 kHz. Finishes are satin light oak, satin American walnut and white or black lacquer. Apertura is a family business in which Christian Yvon handles acoustic design and Eric handles mechanical design and production, and very few subcontractors are used. The Stela was designed to be easy to position, so it can sit fairly near a rear wall because of its modest size.

Pairing

The steady load lets the Stela work with integrated amplifiers from about 30 W per channel, including valve designs. Its compact footprint suits rooms of 12 to 25 m2.

Alternatives

Apertura's Sensa is the smaller compact floorstander of the same family with a single bass-midrange driver.