Sundown Audio - SA-18 v.2 SA Series 18" Subwoofer D2/D4
The Sundown SA series has been our most popular line since its original introduction in 2009. What better way to create a new version 2 than to upgrade, literally, every single part of the woofer? We started with a larger, more powerful motor to drive the larger 2.75” coil and stronger soft parts – this maintains the perfect balance of the original SA series while also increasing the power handling to 1000-watts RMS.
When designing the SA v.2 series we started out with an FEA optimized motor & coil design capable of 19mm of one-way linear excursion by 70% BL and just over 35mm of x-mech. This motor & coil setup was then mated up to an extremely robust double-layer spider with fully tied-on & doubled-up “XL” tinsel leads (84-Strands of Conductor per lead), 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.
We further improved the voice coil cooling system from the original SA series. This system allows our 2.75″ coil to match and exceed the thermal performance of many competing 3″ coil drivers on the market without requiring the usage of a much heavier voice coil than required for the design. The key to the SA series is, in fact, the perfect balance of motors force to mass. We have maintained that delicate balance in the v.2 through extensive testing and optimizations.
We then borrowed the new frame, aluminum surround bolt-on clamps, and aluminum vent rings that we tooled for the U-Series to further bring the SA to new heights of performance and reliability. At this point you can think of it as a little brother to the U Series.
This 18 inch model features a larger motor than the SA-10/12/15 v2 at a full 205mm diameter and a 60mm magnet stack height. The top plate is also thicker in order to more effectively move the higher mass 18″ soft parts. It has a large 234mm diameter spider pack for very high mechanical stroke capacity. It utilizes the same 2.75″ coil as the other SA v.2 series for a 1000-watt RMS power rating.
- Xmax = 19mm one-way by 70% BL
- RMS Power = 1000-watts
- Vented magnetic gap
- Optimized high-velocity pole vent
- Innovative high-velocity vented frame spacer ring
- Black Aluminum 2.75” voice coil former for superior heat dissipation
- High Temperature copper voice coil wire
- Large aluminum faraday ring (Magnet ID)
- Spring Loaded Terminals
- Stitched-On Double “XL” Tinsel Leads to prevent fatigue and failure
- High strength cast aluminum frame
- Optimized for small ported, sealed, & band-pass enclosures
List of upgrades compared to the v1 SA series (Rev.1,2,3):
- Magnet outer diameter increased from 180mm to 190mm
- Magnet slugs increased from 25mm to 27mm in height (total 4mm more height)
- Motor structure fully bolted together with 3x M6 bolts (eliminates the possibility of motor shifting)
- Top-Plate “Slits” implemented as with the X and Z series. Increased cooling & reduced distortion.
- Improved gap venting — more / flared gap vents.
- Improve pole-vent design — smoothly flared on both sides.
- Coil increased from 63.5mm (2.5″) to 70mm (2.75″) in diameter. Higher thermal capacity.
- New “U series” style cast-aluminum frame for taller cones (more x-mech both top-side from cone to spider and bottom from spider to top plate)
- Aluminum cast gasket to bolt-on surround.
- Aluminum cast vent ring to enhance thermal transfer from motor to the frame.
- Standard with double “XL” leads and “bolted-on” spider
- Larger and thicker surround (same tooling as U series).
- Strongest paper cones we have ever produced… new two-piece mold technique.
- “Large Flange” dust cap just like our larger woofers. Essentially eliminates dust-cap glue failure.
- Larger spider diameter on the 12/15″ models (the 10″ retains the same 188mm spider)… 12″ up to ~200mm and 15″ up to ~210mm
- Improved spider material for longer life.
SA V.2 18"
T/S SPECS SAV2 18″ D2 SAV2 18″ D4 RE (Ohms) 3.97 6.06 FS (Hz) 29.051 31.868 VAS (L) 114.234 106.964 Qes 0.424 0.458 Qms 3.052 2.853 Qts 0.372 0.395 Le (mH) 3.6326 4.7903 BL (NA) 32.523 38.159 Mms (Grams) 619.174 549.519 Cms (uM/N) 48.474 45.389 Sens (dB @ 1w/1m) 90.1 90.7
SA V.2 18"