Brand NEW! Including 90 Days USA Factory Warranty. The Dayton Audio Reference Series sets a new standard of value in high-performance loudspeaker drivers. Woofer features a black anodized cone, heavy-duty 6-hole cast frame, low-loss rubber surround, solid aluminum phase plug, and gold terminals. Highlights 4 ohm impedance is perfect for series pairs in MTMs and center channel speakers Excellent car audio midrange/midbass High-end low-distortion motor with two shorting paths to reduce inductance The Dayton Audio Reference Series sets a new standard of value in high-performance loudspeaker drivers. Utilizing a low-distortion motor system with two short-circuit paths and a rigid aluminum cone, the Reference Series can outperform drivers that cost several times the price. Their low-distortion characteristics and high excursion capabilities provide exceptional clarity, detail, and dynamics. Woofer features a black anodized cone, heavy-duty 6-hole cast frame, low-loss rubber surround, solid aluminum phase plug, and gold terminals. Product Specifications Nominal Diameter - 5" Power Handling (RMS) - 30 Watts Power Handling (max) - 60 Watts Impedance - 4 ohms Frequency Response - 65 to 5,400 Hz Sensitivity - 89.9 dB 2.83V/1m Voice Coil Diameter - 1" Thiele-Small Parameters Resonant Frequency (Fs) - 57.2 Hz DC Resistance (Re) - 2.9 ohms Voice Coil Inductance (Le) - 0.28 mH Mechanical Q (Qms) - 2.04 Electromagnetic Q (Qes) - 0.45 Total Q (Qts) - 0.37 Compliance Equivalent Volume (Vas) - 0.187 ft. Mechanical Compliance of Suspension (Cms) - 1.35 mm/N BL Product (BL) - 3.63 Tm Diaphragm Mass Inc. Airload (Mms) - 5.7g Maximum Linear Excursion (Xmax) - 4 mm Surface Area of Cone (Sd) - 52.8 cm Materials of Construction Cone Material - Aluminum Surround Material - Rubber Voice Coil Wire Material - Copper Voice Coil Former - Aluminum Basket / Frame Material - Cast Aluminum Magnet Material - Ferrite Mounting Information Overall Outside Diameter - 4.94" Baffle Cutout Diameter - 3.7" Depth - 2.13" Bolt Circle Diameter - 4.43" # Mounting Holes - 6 Optimum Cabinet Size (determined using BassBox 6 Pro High Fidelity suggestion) Sealed Volume - 0.05 ft. Sealed F3 - 139 Hz Vented Volume - 0.12 ft. Vented F3 - 79 Hz - All international buyers are responsible for all tax, duties and/or customs fees.