Induction Dynamics SW4-BG SubwooferInduction Dynamics SW4 Subwoofer in Black Gloss Note: Minimum lead time of 3 weeks on all Induction Dynamics products. Contact Customer Service if you would like more information. Speakers sold individually. This product has a high saturation filter circuit to eliminate resonance peak. The compact SW4 10 inch subwoofer has the same great sound you've come to expect from the SW series, but it takes up less than a cubic foot. All SW series subwoofers