Description:MB Quart Reference subwoofer with dual 4 Ohm design delivers 600 watts and features heavy gauge, powder-coated, aluminum die-cast basket.Features & Benefits: Terminal TypePush & insert style terminals for easy installation. ConfigurationRound Surround / Cone CouplingThe pressure treated double stitched foam surround along with the dual poly cotton spider helps keep the piston motion of the subwoofer linear and distortion free. Voice Coil / Former AssemblyVented aluminum former holds a 1.5" voice coil while allowing the heat to be exchanged. (Less heat means less distortion) SpiderSpecialized MB Quart dual poly cotton spider with double centering allows the woofer to handle more power with minimum distortions. Frame / VentingHeavy duty aluminum die-cast basket allows back venting, which exchanges heat with cool air, resulting in more power handling and increased reliability. MotorVented high energy motor assembly with heavy duty magnets increases power handling and increases SPL. ConeNon-Pressed Paper Cone with Coating Details & Specs: Color: Black Warranty: 1 Year Compatible Vehicles: Universal Subwoofer Configuration: Round Subwoofer Voice Coils: 2 Subwoofer Impedance (ohms): 4 Subwoofer RMS Power Handling (watts): 300 Subwoofer Peak Power Handling (watts): 600 Subwoofer Cut-Out (in): 5.94 Subwoofer Mounting Depth (in): 4.17 Subwoofer Outside Diameter (in): 7.16 Subwoofer Sensitivity (1 watt/1 meter): 83dB Subwoofer Enclosure Recommendation: Vented enclosure for spl or sound quality – See manual for recommendations Subwoofer Size (in): 6.5 Proposition 65 Notice: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov Recommended Enclosures: VENTED ENCLOSURE SOUND QUALITY Volume (Vb ft³) –3dB Frequency (F3 Hz) Tuning Frequency (Fb Hz) Port Diameter (in) Port Area (in²) Port Length (in) 0.50 41 45 2.5 4.91 8.13