Incredibly linear frequency response characteristics, extreme high power handling while generating the lowest harmonic distortion of any comparable 18-inch transducer within its application range. The L18P400 uses a fiber loaded cone assembly along with a high excursion triple roll, constant geometry surround. A fully optimized T-pole design generate the minimum amount of flux modulation. The T-pole also features RCF Precision's spaced gap demodulation technology, progressively braking the voice coil, providing a much smoother transition for the moving mass as it reaches its maximum excursion limits. Forced air venting system. || Features || 4-inch, fiberglass inside/outside copper voice coil || 2000W continuous program power handling || 97.5 dB Sensitivity || 25 Hz – 1 kHz Frequency range || Aluminum demodulation ring || Forced air ventilation and 15mm top plate for minimum power compression || Dual spider design with silicon based dampening control || Triple roll surround and corrugated straight cone geometry || SPECIFICATIONS || Nominal Diameter : 18 inch / 457 mm || Rated Impedance : 8 ohm || Program Power (watt) : 2000 W || Power handling capacity : 1000 W || Sensitivity : 97.5 dB || Frequency range : 25 - 1000 Hz || Effective piston diameter : 395 mm / 15.55 inch || Max. Excursion Before Damage : 50 mm / 1.97 inch || Minimum Impedance (ohm) : 6.5 ohm || Voice Coil Diameter : 4.0 inch / 102 mm || Voice Coil Winding Material : Copper || Voice Coil Length : 25 mm / 0.98 inch || Number of layers : 2 || Kind of layers : inside/outside || Top Plate Thickness : 15 mm / 0.59 inch || Cone Design : Straight || Surround Material : Polycotton || Surround Design : Triple roll || Magnets : Ceramic || Dual-force air ventilation : Yes || Spider : 3 || THIELE - SMALL PARAMETERS || Resonance frequency (Fs) : 29 Hz || DC resistance (Re) (ohm) : 5.10 ohm || Mechanical factor : 7.60 Qms || Electrical factor : 0.29 Qes || Total factor : 0.28 Qts || Bl factor (Bl) (T x m) : 24.60 T x m || Effective moving mass (Mms) : 200.0 g || Equivalent Cas air loaded (Vas) : 340.0 liters || Effective piston area (Sd) : 0.120 m2 || Max. linear excursion (Xmax) : 9 mm || Voice coil inductance @ 1kHz (Le1k) : 1.20 mH || Half-space efficiency (Eff) : 0.0263 || MOUNTING INFORMATION || Overall diameter : 18.31 inch || Bolt circle diameter : 17.4-17.6 inch || Bolt hole diameter : 0.28 inch || Front mount baffle cut-out : 16.69 inch || Rear mount baffle cut-out : 16.73 inch || Volume occupied by the driver : 0.24 ft|| SIZE || Height : 8.11 inches || Diameter : 18.31 inches || Weight : 29.76 lbs || SHIPPING INFORMATION || Package Height : 10.63 inch || Package Width : 20.47 inch || Package Depth : 19.69 inch || Package Weight : 34.17 lbs