Напольная акустика — Stenheim Reference Ultime Three (Passive)

The Reference Ultime Three (Passive) is the version of the Stenheim Reference Ultime Three tower that uses a passive crossover, so a single stereo amplifier can drive it. Stenheim also offers the model with an active analogue crossover, and in that form Stenheim quotes an extension down to 15 Hz. The Swiss maker builds the cabinet from billet aluminium, and each speaker weighs 240 kg.

Key specs that matter

The passive version covers 25 Hz to 100 kHz. Sensitivity is at least 96 dB SPL at 2.83 V and 1 m, nominal impedance is 4 ohm, and power handling is 1000 W RMS. The driver set counts four 32 cm high excursion woofers, two 16.5 cm neodymium midrange units, one neodymium tweeter plus a ribbon unit for the highest octaves, with an extra backward-firing ribbon available as an option. Height is 167 cm, width 37 cm and depth 56 cm.

Engineering and use context

On the front, the midrange pair flanks the tweeter in a d'Appolito arrangement and two woofers join them, while the remaining pair of woofers faces backwards. The system is a four-way, phase coherent design built with high grade components. In the passive version the crossover is not inside the speaker but housed in two separate enclosures, and jumpers on a control panel let the owner change the gain of the midrange and tweeter section. An optional motorised mechanism adjusts the angle of that MTM section. Inside the aluminium shell the volume is split into six independent closed chambers with no ports, and the walls are braced and damped with three-layer damping pads. Stenheim grants a five year warranty after registration. With this size and weight the speaker is intended for spaces much larger than 20 m2, and the floor beneath it must carry a large point load.

Pairing

Stenheim notes that the speaker does not need massive power even in this large format, yet the demanding load and the four big woofers on each side favour a transistor stereo or mono amplifier with a strong power supply and good current delivery. Buyers who later want more control over the bass can move to the active version, whose bass section is rated at 1400 W RMS and whose midrange and tweeter section is rated at 250 W RMS, with separate amplifier channels for each.

Alternatives

The Stenheim Alumine Three SE is a far more compact floorstanding model at 105 cm and 70 kg, with a 93 dB sensitivity and an 8 ohm nominal load.