Напольная акустика — Wlm Rudolf

The Rudolf is a slim passive tower speaker built by the Viennese firm Wiener Lautsprecher Manufaktur (WLM), a company that also builds fully active systems. It shares the narrow faceted cabinet shape of the active Maria but relies on an external amplifier, and its successor is the reworked Rudi MK2, which grew in size and moved from a 2.5-way to a three-way layout. German list pricing for the Rudolf was about EUR 11,900 per pair.

Key specs that matter

The Rudolf uses six drivers. Two 18 cm long-stroke units with paper membranes cover the bass, two 5 inch woofer-midrange drivers use Kevlar cones, a graphite-membrane cone tweeter of 5 cm sits alongside, and a 6 cm AMT tweeter is mounted as a dipole. WLM quotes a frequency response of 30 Hz to 31 kHz and an efficiency of 94 dB. The enclosure is 98 cm tall and 34 cm deep, with a width of 13 cm at front and back that grows to 19 cm in the middle, and each speaker weighs 26 kg.

Engineering and use context

The cabinet combines two loading principles. A transmission line in the bass range radiates toward the rear, while a bass reflex section in the low and mid range fires downward, so the speaker must stand on its tall spikes to leave room under the bottom opening. Inside the line the path is folded both upward and downward. Wall thickness is between 1.9 cm and 3.8 cm, thinner than in the active models. The two midrange drivers flank the tweeters in a D'Appolito arrangement, which concentrates vertical dispersion. A discreet switch on the cabinet engages alternative filter characteristics, and a rear potentiometer adjusts the tweeter level. The terminals accept bi-wiring. Standard cabinets are veneered MDF, and a light hardwood veneer can be ordered, while fabric covers hide the upper woofer assembly. The narrow baffle follows WLM practice of limiting edge diffraction, and the octagonal basic form is used by the brand to spread cabinet resonances.

Pairing

The high sensitivity means modest amplifier power is enough for normal listening levels, which opens the door to valve designs of relatively low output as well as compact transistor integrated amplifiers. Owners who want to split the bass and upper sections can use the bi-wire terminals with separate speaker cable runs from a single amplifier.

Alternatives

The WLM Ella MK II is a smaller floorstanding model of the brand, intended for more compact rooms.