The Eminence Legend CB158 15" Bass Speaker delivers the full, round bass tone you want from a 15" speaker. Recommended for professional bass guitar applications in a sealed or vented enclosure. Nominal Basket Diameter: 15", 381mm Nominal Impedance: 8 ohms Power Rating: 300W Resonance: 34Hz Usable Frequency Range: 47Hz-3kHz Sensitivity: 98 Magnet Weight: 80 oz. Gap Height: 0.375", 9.53mm Voice Coil Diameter : 2.5", 63.5mm Thiele & Small Parameters Resonant Frequency (fs): 34Hz DC Resistance (Re): 6.15 Coil Inductance (Le): 0.33mH Mechanical Q (Qms): 5.9 Electromagnetic Q (Qes): 0.36 Total Q (Qts): 0.34 Compliance Equivalent Volume (Vas): 336 liters / 11.9 cu. ft. Peak Diaphragm Displacement Volume (Vd): 411cc Mechanical Compliance of Suspension (Cms): 0.31mm/N BL Product (BL): 16.0 T-M Diaphragm Mass inc. Airload (Mms): 70 grams Efficiency Bandwidth Product (EBP): 95 Maximum Linear Excursion (Xmax): 4.8mm Surface Area of Cone (Sd): 856.3 cm2 Maximum Mechanical Limit (Xlim): 9.5mm Mounting Information Recommended Enclosure Volume Sealed: 54-65 liters/ 1.9-2.3 cu.ft. Vented: 54-159 liters/ 1.9-5.6 cu.ft. Overall Diameter: 15.21", 386.4mm Baffle Hole Diameter: 14.0", 355.3mm Front Sealing Gasket: fitted as standard Rear Sealing Gasket: fitted as standard Mounting Holes Diameter: 0.28", 7.1mm Mounting Holes B.C.D.: 14.56", 369.9mm Depth: 6.5", 165mm Net Weight: 17.3 lbs., 7.9 kg Shipping Weight: 19.4 lbs., 8.8 kg Materials of Construction Copper voice coil Polyimide former Ferrite magnet Vented and extended core Die-cast aluminum basket Paper Cone Cloth cone edge Solid composition paper dust cap Please inquire about alternative impedances. Multiple units exceed published rating evaluated under EIA 426A noise source and test standard while in a free-air, non-temperature controlled environment. The average output across the usable frequency range when applying 1W/1M into the nominal impedance. Ie: 2.83V/8ohms, 4V/16ohms. Eminence response curves are measured under the following conditions: All speakers are tested at 1w/1m using a variety of test set-ups for the appropriate impedance ¦ LMS using 0.25" supplied microphone (software calibrated) mounted 1m from wall/baffle ¦ 2ft. X 2ft. baffle is built into the wall with the speaker mounted flush against a steel ring for minimum diffraction ¦ Hafler P1500 Trans-Nova amplifier ¦ 2700 cu.ft. chamber with fiberglass on all six surfaces (three with custom-made wedges).