SA Classic Series 12" 750W Subwoofer4 Ohm Dual Voice CoilHere at Sundown Audio we take feedback from customers and dealers seriously. With the launch of the SA v.2 woofers we heard a lot of call to also keep the old version for lower depth / lower cost applications — so we did that via the “Classic” SA. Still available in 10s and 12s it is essentially the SA v.1 Rev.3 but with a black motor finish. We even squeezed in an upgrade… the motor is bolted together for enhanced long-term durability!The Sundown SA series has been our most popular product line since the introduction of the SA-12 in 2009. It was the result of over a year of testing and prototyping until all of our goals and expectations were blown away. The SA series has continually evolved over the years thanks to extensive testing and feedback from our SPL competition Team and our customers but still stays true to its legendary design heritage. It has never failed to prove itself year-in and year-out in every application ranging from daily musical builds to all-out SPL competition vehicles.When designing the SA series we started out with an FEA optimized motor & coil design capable of 19mm of one-way Klippel verified excursion and just over 33mm of x-mech. This motor & coil setup was then mated up to an extremely robust double-layer Nomex spider with fully tied-on “XL” tinsel leads (84-Strands of Conductor), an SPL competition grade paper cone, and a strong foam surround. The motor also features a large magnet ID shorting ring (faraday ring) to reduce distortion causes by inductance & inductance variation over stroke.FEATURESXmax = 19mm one-way by 70% BLRMS Power = 750-wattsVented magnetic gapOptimized high-velocity pole ventInnovative high-velocity vented frame spacer ringBlack Aluminum 2.5” voice coil former for superior heat dissipationHigh Temperature copper voice coil wireLarge aluminum faraday ring (Magnet ID)Spring Loaded TerminalsStitched-On “XL” Tinsel Leads to prevent fatigue and failureHigh strength cast aluminum frameOptimized for small ported, sealed, & band-pass enclosuresThese features combine to create the optimized coil ventilation system.SPECIFICATIONST/S SPECSSA CLASSIC 12" D2SA CLASSIC 12" D4RE (Ohms)4.577.07FS (Hz)33.7133.96VAS (L)21.2124.63Qes0.580.55Qms5.345.15Qts0.520.49Le (mH)3.404.84BL (NA)21.6425.67Mms (Grams)280237Cms (uM/N)79.4392.27Sens (dB @ 1w/1m)83.2184.22 ENCLOSURE SPECIFICATIONSSA CLASSIC 12"Sealed Enclosure1.0 cu ftPorted Enclosure1.75 cu ftRecommended Tuning35HzRecommended Port Area26 sq inDisplacement0.14 cu ftDepth6.5″Outside Diameter12.625″Cut-Out11.125″