Luxman LX77

The Luxman LX77 is a 3-way, 3-speaker, airtight bookshelf system introduced in September 1971 at ¥43,800 per unit (later listed around ¥48,000). It is one of the earlier Luxman speakers to use the company's own ring-type tweeter. That tweeter has a 3.3 cm ultra-hard duralumin ring diaphragm, which Luxman developed to eliminate split vibrations within the audible band. The midrange is a 4 cm dome, also hard duralumin, with a free-edge fiber surround. The low end is a 30 cm high-compliance cone with a long voice coil, meant to reduce non-linear distortion and mechanically roll off unwanted high frequencies.

The crossover points are 700 Hz and 8 kHz, with an 18 dB/octave slope. Both the mid and high drivers get constant-impedance AS-6X type level controls. The enclosure is particle board - 25 mm on the top, bottom, and sides, 20 mm front and rear - finished in rosewood, with bond acetate fiber as the internal damping material. Multi-amplifier terminals are fitted, so you can bi-amp or tri-amp. Rated input is 30W (60W maximum) at 8 ohms. Frequency response is 30 Hz to 22 kHz, and the lowest resonance frequency is 55 Hz. Dimensions are 388 × 666 × 310 mm, and each speaker weighs 22.5 kg.

Type: 3-way, 3-speaker, airtight bookshelf
Woofer: 30 cm cone, high-compliance free edge
Midrange: 4 cm dome (hard duralumin)
Tweeter: 3.3 cm ring type (LUX-developed)
Frequency response: 30 Hz – 22,000 Hz
Crossover: 700 Hz / 8,000 Hz (–18 dB/oct.)
Impedance: 8 Ω; Rated/Max input: 30W / 60W
Dimensions: 388 × 666 × 310 mm; 22.5 kg

No period reviews of the LX77 have turned up in the archival record. Little is documented about its market reception or production span, beyond the conflicting release dates in the Japanese price listings. A related model, the LX77B, is sometimes discussed alongside it, but the two are not the same speaker. The LX77B appears to have used different drivers (including a 12-inch alnico woofer and metal dome mid/tweeter) and tri-wirable terminals. A Russian forum post from an owner simply notes buying a pair of LX-77s, and one thread asks about the stiffness of the bass driver surrounds. No detailed evaluations or common failure reports are documented.