The new SSDv4 Series of subwoofers is our all around daily sub. Utilizing our new water jet we are cutting the top plates and back plates in house as well as final machining. This new design uses a wide single high grade ceramic ferrite magnet for more force and increased motor force over the previous model. Now with the option for our Heli-cool system using our billet machined solid pole, the cooling capability has been massively increased. Along with dual 8″ progressive spiders, a multilayer foam surround attached to a fiber impregnated kraft pulp cone helps keep things under control in high power applications. The 3″ 4 layer aluminum voice coil has been increased to 29 mm of Xmax. Light weight and versatile, the SSD works in a variety of applications from incredibly detailed sound quality systems, to ground pounding multi sub monsters. The SSD is versatility redefined. Coils DUAL 1 | DUAL 2 FS 34.8 Hz RE 0.7| 1.4 QMS 6.89 QES 0.50 QTS 0.48 MMS 424g CMS N/A SD 1210cm^2 VAS 101.0 l SPL 91.0dB BL 16.0N/A | 22.6 N/A XMAX 28mm (One Way) RMS 1500W