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" 4-layer underhung voice coil with polyimide former Dayton Audio's ND140-8's compact aluminum cone demonstrates the latest advances in high-excursion design processes. Its compact size and high output make it perfect for your next point-source or line array speaker project. When teamed up with the matching ND series passive radiators this driver can produce incredible full sound from compact enclosures.