Floorstanding loudspeakers — Blumenhofer Acoustics Classic 1743

The Classic 1743 is one of three models in the Classic series from Blumenhofer Acoustics, a German horn loudspeaker company whose development and production sit in a natural park in the south of Germany, not far from Munich. Thomas Blumenhofer has built hi-fi speakers there since 1977. The Classic line was created together with Old School HiFi, which wanted speakers with a vintage appearance that still follow Blumenhofer engineering, and the maker admits the project ran longer than planned and yielded several spin-offs. Below the 1743 sit the three-way 1733 and the two-way 1722. The whole series is now listed on the archive site Blumenhofer keeps for retired models.

Key specs that matter

Four drivers per cabinet form a three-way layout. A pair of 380 mm (16 inch) paper woofers covers the bottom octaves and hands over at 215 Hz to a 300 mm (12 inch) paper midrange. Above 800 Hz a compression driver takes over, loaded by a horn with a 1.4 inch throat and fitted with a 75 mm (3 inch) titanium diaphragm. The rated frequency range is 30 Hz to 20 kHz within plus or minus 2 dB. Each enclosure measures 123 x 85 x 46 cm and weighs 90 kg.

Engineering and use context

Walls of 18 mm HDF complex board form each 1743 cabinet, with structural bracing interaction inside to stiffen the panels. The low-frequency section works as a bass reflex enclosure whose port opens on the front baffle. Because the two big woofers share the lowest band, the midrange cone only has to work up to the upper crossover, and the titanium compression driver handles everything from there to the top of the range. Compared with the 1733, the 1743 moves to a larger horn throat and a titanium rather than Mylar diaphragm, and it is the only Classic model with bi-wiring terminals, which are gold-plated tellurium copper. Spike feet come with each speaker. Given its mass, the 1743 ships one speaker per crate, and the crate measures 135 x 90 x 60 cm.

Pairing

Blumenhofer gives an efficiency of 97 dB and a nominal impedance of 8 ohm. The maximum power input is 250 W RMS, which is the ceiling the maker states for amplifier output. Thanks to the split terminal panel, each speaker can be connected with two separate pairs of speaker cable rather than one, which the smaller Classic models do not allow.

Alternatives

The Blumenhofer Classic 1733 sits one step lower in the Classic range as a three-way tower with a single woofer, a 250 mm midrange and a 106 x 46 x 42 cm cabinet weighing 35 kg.