Dayton Audio ND140-8 5-1/4" Aluminum Cone Midbass Neo Driver 8 Ohm Extended-range 54 Hz to 8 kHz performance Rubber-edged aluminum alloy cone Large excursion capability-4 mm Xmax, 20 mm peak Self-shielded Neo-Balanced motor structure 1&quot; 4-layer underhung voice coil with polyimide former