Sundown Audio U-Series v.1 15" Subwoofer

The Sundown U Series is our premier “standard suspension” woofer series. It is the most direct replacement for the world famous Z v.3 woofer line which we produced from 2011 to 2016 before launching the “new platform” Z v.4 series. Due to numerous advancements in our design process the U Series is able to deliver performance on-par with the Z v.3 series but at a much lower cost. We start with a double-stacked / 8.66” wide Y35 grade ferrite magnet system coupled to a one-piece, bumped T-Yoke and a 0.6” thick top-plate. Just as with the Z v.3 before it and our other high-end subwoofers we also add a very thick (5mm thickness) aluminum shorting ring inside the magnets to reduce static inductance and level out inductance over stroke. The U series motor also features a 0.6” long pole-extension to keep the coil under control at high levels of excursion. The voice coil is a 2.36” long / 3” diameter 4-layer aluminum winding / aluminum former unit – which is the same coil we use in our X v.2 series and, thus, the U series has the same 1500-watt RMS ratings. The coil temperature is kept in check by a heavily smoothed / high-velocity pole-vent and a series of ten direct air-gap vents in the back plate. The U series also features newly tooled cast aluminum vent rings in between the frame and top plate to effectively exchange air at a high velocity over the voice coil beneath the spider landing. The U series features an all-new cast aluminum frame series to the Sundown line which allows for taller cones than the older frames used on the Z v.3 series. The taller cones provide enhanced coil stability and increased mechanical excursion capability. We also tooled matching cast-aluminum surround clamps for the U series to ensure durability in the most demanding situations. The surrounds and cone bodies have been fully custom tooled especially for the U series and are stronger / support more excursion than the Z v.3 series cones and surrounds. The new cone bodies also feature an indentation for the same wide-flange, ultra-strong dust caps as our new platform subwoofers. If you are looking for a woofer that sounds similar to the SA series but handles significantly more power… the U series is exactly what you need. It has been designed to live up to the reputation earned by our Z v.3 series both in terms of every-day music enjoyment and SPL competition. Specifications Black Aluminum 3” voice coil former for superior heat dissipation High Temperature Round-Wire CCAW voice coil with high-temp black adhesive Double stitched surround Heavy duty cast basket Spring loaded terminals accept up to 8 gauge Stitched-on double-XL tinsel leads Rear vented pole piece Rear drilled gap-venting Innovative high-velocity cast aluminum vented frame spacer ring Magnet ID shorting ring Top-Plate Cooling Channels Cast Aluminum surround bolt-on rings Optimized for small ported or bandpass enclosures Specifications T/S SPECS U 15" D2 U 15" D4 RE (Ohms) 3.8 6.1 FS (Hz) 37.9 34.9 VAS (L) 54.0 63.9 Qes 0.34 0.39 Qms 3.10 3.48 Qts 0.31 0.35 Le (mH) 2.44 3.80 BL (NA) 30.7 34.6 Mms (Grams) 355.7 353.0 Cms (uM/N) 0.05 0.06 Sens (dB @ 1w/1m) 91.2db 90.2db