H 417 Response curve recorded in an anechoic chamber (Free-field, 4 pi radiation) with 0.5m microphone distance. The loudspeaker is mounted in a 0.6m by 0.8m baffle. OF NORWAY TWEETER 25TAC/GW Cumulative spectral decay 25mm High Fidelity dome tweeter with glass fibre reinforced plastic chassis. The unit features high efficiency and smooth, extended response. Its aluminium diaphragm with critically designed shape and thickness behaves like a piston throughout the audible frequency range, resulting in good dispersion above 10 kHz. A fine mesh grid protects the diaphragm, and supports a phase plate which compensates for a slight axial roll off towards 20 kHz. The specially designed soft surround allows excellent mechanical linearity. A damped hole in the pole piece and a tuned chamber behind the magnet result in a low resonance frequency. The unit is equipped with flexible lead out wires, allowing relatively low crossover frequencies to be used. 6 NOMINAL IMPEDANCE RECOMMENDED FREQUENCY RANGE Ohms 2000-25000 Hz SHORT TERM MAXIMUM POWER* 150 W LONG TERM MAXIMUM POWER* 60 W VOICE COIL RESISTANCE VOICE COIL INDUCTANCE (EQUIVALENT) 0.05 mH VOICE COIL DIAMETER 26 mm VOICE COIL HEIGHT 1.5 mm CHARACTERISTIC SENSITIVITY (1W , 1m) 91 dB SPL MOVING MASS OPERATING POWER (96 dB SPL , 1 m) 3.2 W EFFECTIVE PISTON AREA 7.0 sq.cm LINEAR COIL TRAVEL ( p-p ) 0.5 mm AIR GAP HEIGHT 2.0 mm MAGNETIC GAP FLUX DENSITY 1.8 T FREE AIR RESONANCE 660 Hz FORCE FACTOR 3.5 N/A NOTES MAGNET WEIGHT 0.25 Kg TOTAL WEIGHT 0.50 Kg * IEC 268-5, VIA HIGH PASS BUTTERWORTH FILTER: JUL.96 T25-303 4.8 Ohms 0.33 g 3000 Hz 12 dB/oct.