Aura made their 1808 driver in 80s and most of the 90s and it was wonderful. It had huge high-temperature neodymium magnet, unique magnet geometry with underhung 4" edgewound aluminum voice coil. It was the only 18-inchers underhand voice coil ever produced. The finny part that despite of the underhand configuration it had 98dB sensitivity with 2” total excursion – what a motor! The driver had paper cone, cloth suspension and had phenomenal articulation at lowest frequencies. The 1808 was suggested for 20 Hz - 200Hz but it did not sound good even at 80Hz. The Aura 1808 had free air resonance at 24Hz and required enormous sealed enclosure of 14-16 cu feet. Wilson Audio used the Aura 1808 in their unfortunately-ported XS subwoofers and soaked from their relatively small enclosure an extra 19dB of port noise at 20Hz. Rgs, Romy the Cat |