There is a quantity of four at the start of this listing. These woofers are each in the same near mint to mint condition with slight use. They still maintain they’re original sonic performance matching all original specifications. The Aurum Cantus AC300/75C2C 12 woofer features a 3 diameter voice coil, which combined with extensive thermal management techniques provides outstanding power handling and realistic impact. The tailored response of the speaker's exotic yet supremely engineered non-woven carbon fiber sandwich cone delivers the signature Aurum Cantus combination of depth, accuracy, and listenability. A copper-plated flat aluminum wire voice coil provides high efficiency and excellent power handling, complemented by a low-distortion magnet system and precisely cast aluminum alloy basket. Aurum Cantus woofers are characterized by fast transient response, minimal tonal coloration, and deep, dynamic bass. If you have any questions please feel free to contact us, and thank you for looking! Product Specifications: Nominal Diameter12 Power Handling (RMS)250 Watts Power Handling (MAX)375 Watts Impedance8? Frequency Response22 to 2,800Hz Sensitivity91dB 2.83V/1m Voice Coil Diameter3 Thiele-Small Parameters: Resonant Frequency (Fs)22Hz DC Resistance (Re)7? Voice Coil Inductance (Le)1.31mH Mechanical Q (Qms)2.16 Electromagnetic Q (Qes)0.42 Total Q (Qts)0.35 Compliance Equivalent Volume (Vas)8.19ft³ Mechanical Compliance of Suspension (Cms)0.65mm/N BL Product (BL)13.2T·m Diaphragm Mass Inc. Airload (Mms)84g Maximum Linear Excursion (Xmax)8.5mm Surface Area of Cone (Sd)500cm² Materials of Construction: Cone MaterialCarbon Fiber Surround MaterialRubber Voice Coil Wire MaterialCCA Voice Coil FormerKapton® / Polyimide Basket / Frame MaterialCast Aluminum Magnet MaterialFerrite Mounting Information: Overall Outside Diameter12.99 Baffle Cutout Diameter11.1 Depth5.59 # Mounting Holes8