ALPHA-12A Recommended for professional audio mid-bass applications in a small sealed or medium vented enclosure. Click Here to Download 8 ohm PDF Spec Sheet Click Here to Download 8 ohm PDF Cabinet Design Specs: Nominal Basket Diameter 12″, 304.8mm Nominal Impedance* 8 ohms Power Rating Watts 150W Music Program 300W Resonance 49Hz Usable Frequency Range 51Hz-4.3kHz Sensitivity*** 95.6 Magnet Weight 20 oz. Gap Height 0.25″, 6.35mm Voice Coil Diameter 1.5″, 38.1mm Thiele & Small Parameters: Resonant Frequency (fs) 49Hz DC Resistance (Re) 6.3 Coil Inductance (Le) 0.79mH Mechanical Q (Qms) 6.53 Electromagnetic Q (Qes) 0.88 Total Q (Qts) 0.77 Compliance Equivalent Volume (Vas) 121.5 liters / 4.3 cu.ft. Peak Diaphragm Displacement Volume (Vd) 125cc Mechanical Compliance of Suspension (Cms) 0.32mm/N BL Product (BL) 8.5 T-M Diaphram Mass inc. Airload (Mms) 33 grams Efficiency Bandwidth Product (EBP) 56 Maximum Linear Excursion (Xmax) 2.4mm Surface Area of Cone (Sd) 519.5 cm2 Maximum Mechanical Limit (Xlim) 6.6mm Mounting Information: Recommended Enclosure Sealed 17-22.7 liters/0.6-0.8 cu.ft. Vented 56.6-113.3 liters/2-4 cu.ft. Overall Diameter 12.26″, 311.4mm Baffle Hole Diameter 11″, 279.5mm Front Sealing Gasket Fitted as standard Rear Sealing Gasket Fitted as standard Mounting Holes Diameter 0.25″, 6.4mm Mounting Holes B.C. D. 11.71″, 297.5mm Depth 4.73″, 120mm Net Weight 5.3 lbs., 2.4 kg Shipping Weight 7.4 lbs., 3.4 kg Materials of Construction: Coil Construction Copper voice coil Coil Former Polyimide former Magnet Composition Ferrite magnet Core Details Vented and extended core Basket Materials Pressed steel basket Cone Composition Paper Cone Cone Edge Composition Cloth cone edge Dustcap Composition Solid composition felt dust cap