Horn-Loaded Transmission Line
The Antares loudspeaker series, which I developed back in the early 1980s, focussed on audiophile customers with high demands on sound quality. An entry-level model as a 2-way system as well as a mid-range and a top model, each as a 3-way system, were equipped with special, modified speaker chassis in the bass and mid-range, as well as a modified magnetostat for the treble range.
I developed an unconventional, new type of cabinet design for the sub-bass and bass range, which can be described as a horn-loaded transmission line.
In combination with a passive crossover technology, also developed in-house, low bass signals down to just below 20Hz could be achieved at almost full level. In addition, the cabinet design and the unique crossover worked together to completely eliminate the typical resonant frequency from the audible bass range - usually between 25 - 60Hz.
The bass system was operated exclusively above its natural resonance. As a result, there was no increase and no maximum (turning point) of the impedance in the entire audible frequency range. Further measures such as a special capacitive-electric absorption circuit for the mid-range and the magnetostatic tweeter connected at the top ensured a smooth impedance curve without peaks. Only at the ends, below 40Hz and above 15,000Hz, did the impedance rise moderately to around three times the nominal impedance.
In addition to the almost resonance-free, cleanly contoured reproduction of bass, an almost linear impedance curve is also the basis for a largely linear phase response.
Further highlights of the Antares speaker series were bass and midrange drivers with cones made of carbon or aramid fibres as well as sandwich constructions of these materials and hollow honeycomb structures.