Напольная акустика — Odeon Audio HELIX

The Helix is the smallest three-way horn loudspeaker made by Odeon Audio, a small multi-generation company in Haltern am See, North Rhine-Westphalia, Germany. Odeon places it after its earlier designs of 1992 and 2000 as the start of a new generation, and it takes over from the Odeon No. 28/SE. The maker says it was sized to suit both small listening rooms and large living rooms. Nine cabinet finishes are offered, among them walnut root, tiger walnut, poplar, maple burl, white, palisander, walnut, black with gold and macassar.

Key specs that matter

Each cabinet stands 117.5 cm tall, 48 cm wide and 52.5 cm deep and weighs 51 kg. Odeon quotes a range of 30 Hz to 26,000 Hz within 3 dB, a sensitivity of 94 dB and a nominal impedance of 8 ohm. The crossover hands over at 450 Hz and 2,600 Hz. At the top sits a 1 inch compression driver with ring radiator technology, a light Mylar diaphragm and a 2.2 Tesla neodymium magnet, loaded by a 17 cm birch multiplex horn. The midrange is a handmade 13 cm unit from the German firm GAP with a die-cast aluminium basket and a 1.2 Tesla neodymium motor, set behind a 42 cm spherical wave horn cut from layered blocks of birch plywood. Bass comes from a 10 inch Audax paper woofer with an oversized ferrite magnet, built on the same technology as the woofers of the larger Semper and Carnegie.

Engineering and use context

The midrange cone is a hyperbolic NAWI shape in cellulose, and its folded edge replaces a separate rubber surround. A diffraction plug stands in for the dust cap, which brings the moving mass down to 2 grams. The two-part cabinet mixes multiplex with a dense MDF, and its asymmetrical bass enclosure is meant to stop standing waves, so less damping material is needed. Compared with the No. 28/SE, the reshaped bass cabinet holds more internal volume, and all drivers now sit on one vertical axis. The reflex tunnel fires down toward the base plate, as on every Odeon floorstander. Crossover parts are matched to within one percent, use film capacitors from WIMA with New Old Stock bridge capacitors and Mundorf flat and round wire coils, and are wired point to point by hand rather than on a Pertinax board. Internal wiring is German OFC copper, with 7N monocrystalline solid core wire in Teflon for the treble. WBT Nextgen terminals sit on acrylic plates that also carry the crossovers.

Pairing

Odeon states that the Helix works with solid state and tube amplifiers, down to low-power triode designs such as the 300B.

Alternatives

The Odeon Semper is the next three-way horn model up, with a 13 inch woofer, a 50 cm midrange horn and a rated 96 dB sensitivity.