Floorstanding loudspeakers — Blumenhofer Acoustics Corona 4x180 P

The Corona 4x180 P is the paper-woofer version of the Corona 4x180, a two-way horn tower from Blumenhofer Acoustics, whose development and production are located in a natural park in southern Germany close to Munich. Blumenhofer sums the model up as still a 2-way box, but boosted. Its stated aim was to deliver the Blumenhofer approach in a more refined-looking cabinet while keeping speed, horn loading and power, and the company says every technology it had developed over the preceding years went into these speakers, making the build quite complex. A second version, the Corona 4x180 P2C, shares the cabinet but uses Peek-Carbon sandwich woofers. The P suffix marks the paper cones.

Key specs that matter

Four 17 cm (6.5 inch) woofers with paper cones work together in the bass and lower midrange. Above 1000 Hz a 1.4 inch compression driver with a 75 mm (3 inch) titanium diaphragm takes over through a mid-high horn. Frequency range is given as 36 Hz to 20 kHz within plus or minus 2 dB. Each speaker stands 1190 mm tall on a 425 x 605 mm footprint, and weighs 50 kg.

Engineering and use context

Panels are 18 mm birch plywood with structural bracing interaction between them, and the crossover sits in its own separate chamber rather than sharing air with the woofers. The bass enclosure is what Blumenhofer terms a harmonic bass reflex, and its port faces forward from behind the horn. In the harmonic construction concept, non-parallel walls work against standing waves, and each wall is tuned to a defined resonance so that excess energy spreads over a broader chosen band instead of being fully absorbed. The design also uses waveformer technology and time-aligned drivers. Blumenhofer explains that after trying layouts with up to four ways, it settled on the two-way principle and then developed its own compression drivers and front horns so that each driver is matched to one specific horn. A pair of speakers ships in three cartons, two of 70 x 60 x 103 cm and one of 39 x 39 x 115 cm. The spike feet are adjustable, and the maker's warranty covers five years.

Pairing

Blumenhofer rates this version at 94 dB efficiency and 4 ohm impedance, with a power handling of 250 W RMS. A switchable impedance linearisation network at the crossover point is built in for valve amplifiers, which the company believes need a flat load, and the terminals, in gold-plated tellurium copper, accept separate amplifiers for bass and horn.

Alternatives

The Blumenhofer Corona 4x180 P2C is the same tower fitted with Peek-Carbon P2C sandwich woofers and rated for 300 W RMS.