Напольная акустика — Stenheim Reference Ultime Three (Active)

The Reference Ultime Three (Active) is the active crossover version of a four-way floorstanding loudspeaker in the Reference line of the Swiss company Stenheim. The same speaker is also offered with a passive crossover. Moving to the active version is quoted as releasing a further 6 dB of efficiency, but it makes bi-amping a necessity, whereas the passive model can run from a single amplifier.

Key specs that matter

Eight transducers are used in a full d'Appolito arrangement. Four 32 cm high excursion woofers handle bass, two 16.5 cm neodymium midrange drivers flank a neodymium tweeter, and a ribbon super tweeter extends the top, with a back-firing ribbon super tweeter available as an option. Two of the woofers fire from the rear of the cabinet. In active form the response is 15 Hz to 100 kHz, against 25 Hz for the passive version. Power handling is 1,400 W RMS for the bass section and 250 W RMS for the mid and treble section. Sensitivity is at least 96 dB SPL at 2.83 V and 1 m, and nominal impedance is 4 ohm. Each speaker is 167 cm high, 37 cm wide and 56 cm deep, and weighs 240 kg.

Engineering and use context

The cabinet is machined from billet aluminium and divided into six independent closed chambers, which isolates the driver groups from one another. Stenheim describes the system as a passive-active four-way with an analogue crossover in either form. The active crossover sits in an enclosure made by CH Precision, while the electronic board inside is a Stenheim design. An optional motorised MTM section allows the angle of the midrange and tweeter array to be adjusted remotely. A Reference Platform accessory can be fitted under the cabinet. Stenheim extends the warranty to five years on registration. At this mass, delivery and positioning need a team of handlers and a floor rated for the load. The rear-firing woofers also mean spacing from the rear wall changes bass output, and placement should be decided before final installation.

Pairing

Unlike a speaker with built-in amplifiers, this version needs four channels of external amplification, with the low section and the upper section of each speaker driven separately, fed from the external active crossover. Because of the high efficiency, the brand notes that the speaker does not require massive power, so owners can choose amplifiers for quality over sheer output. The crossover takes its signal from a preamplifier, or directly from a player offering level adjustment.

Alternatives

Within the Reference line, Stenheim also builds the Reference Ultime Two, a floorstander one size down.