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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.
| Specification | D2 Model | D4 Model |
|---|---|---|
| RMS Power | 1500 W | 1500 W |
| Peak Power | 3000 W | 3000 W |
| Displacement | 0.18 cu ft | 0.18 cu ft |
| Mounting Depth | 7.007" | 7.007" |
| Outside Diameter | 10.94" | 10.94" |
| Cutout Diameter | 9.17" | 9.17" |
| Motor Diameter | 9.37 | 9.37 |
| Sealed Enclosure | 0.5 cu ft | 0.5 cu ft |
| Ported Enclosure | 1.0 cu ft | 1.0 cu ft |
| Recommended Port Tuning | 35hz | 35hz |
| Recommended Port Area | 16 sq in | 16 sq in |
| Xmax | 30mm | 30mm |
| 4th Order Sealed | .4cu ft | .4cu ft |
| 4th Order Ported | 1.2cu ft | 1.2cu ft |
| 4th Order Port Area | 24sq in | 24sq in |
| 4th Order Port Length | 6" | 6" |
| Parameter | D2 Model | D4 Model |
|---|---|---|
| Re | 3.80 Ω | 6.10 Ω |
| Fs | 48.5 Hz | 41.1 Hz |
| Qms | 3.2000 | 3.2100 |
| Qes | 0.3500 | 0.3900 |
| Qts | 0.3200 | 0.3500 |
| Vas | 8.300 L | 11.500 L |
| Mms | 216.30 g | 219.70 g |
| Cms | 0.05 mm/N | 0.07 mm/N |
| BL | 26.800 T·m | 29.700 T·m |
| Le | 2.56 mH | 3.71 mH |
| Sd | 506.6 cm² | 506.6 cm² |
| Xmax | 30mm | 30mm |
| SPL (1W/1m) | 86.2 dB | 84.9 dB |
