Напольная акустика — Focal STELLA UTOPIA EM EVO

The Stella Utopia EM Evo is a three-way bass-reflex column from the Utopia range of Focal, handcrafted in France. Focal describes it as the technological twin of the Grande Utopia EM Evo in a lighter three-way form, and its woofer motor uses an electromagnet instead of a permanent magnet. The US price is USD 149,998 per pair.

Key specs that matter

A 27 mm IAL2 pure beryllium inverted dome tweeter covers the treble. Two 16.5 cm Power Flower W midrange drivers with TMD suspension and NIC magnets flank it, and a 33 cm W woofer driven by the Grande Utopia electromagnet motor covers the range from low bass to lower midrange. The crossover divides the range at 230 Hz and 2,200 Hz. Focal quotes a response of 22 Hz to 40 kHz within 3 dB, extending to 18 Hz at -6 dB. Sensitivity is 94 dB, measured with 2.83 V at 1 m. The nominal impedance is 8 ohm, the lowest point is 2.8 ohm, and Focal lists suitable amplifier power as 50 to 1,000 W. Each speaker is 155.8 cm tall, 55.3 cm wide and 83 cm deep and weighs 170 kg.

Engineering and use context

Because the motor strength comes from an electromagnet, its force can be modulated, and an external power supply lets the owner set the supply voltage on several levels, changing the bass behaviour. For the Evo version the whole crossover was redesigned around the new drivers. The cabinet gained reinforcement rings around the drivers, and the acoustic wadding inside was made thicker to give better control of the bass. The W cones are a composite sandwich construction, and NIC, the Neutral Inductance Circuit, is the magnetic circuit design Focal uses to stabilise the motors. TMD, the Tuned Mass Damper, sits in the midrange suspension to control resonance. The Power Flower layout places several magnets around each midrange voice coil. The enclosure follows the Gamma Structure, an anti-vibration construction. The OPC+ filter can be customised, with 243 possible combinations of settings. Double terminal boards are fitted. The driver baskets and the tweeter enclosure are finished in Graphite Black, and cabinet colours listed include Metallic Blue, British Racing Green, Black Lacquer, Carrara White, Ash Grey and Hot Chocolate.

Pairing

The high sensitivity means a modest amplifier already drives the speaker, yet with the deep impedance minimum the amplifier must remain stable and supply current into a low load. The double terminal boards allow separate amplification of sections.

Alternatives

The Scala Utopia Evo is the smaller Utopia floorstander, with a single 27 cm woofer on a permanent magnet motor, 92 dB sensitivity, a 3.2 ohm minimum impedance and a weight of 85 kg.