Sundown Audio SA-15 V.2 D4 15" Dual 4-Ohm SA Series Subwoofer

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.

Enclosure Recommendations:

• Mounting Depth: 8.66"
• Cutout Diameter: 14.02"
• Magnet Diameter: 7.80"
• Sealed Enclosure: 2.0 ft^3
• Ported Enclosure: 3.5 ft^3 tuned to 35 Hz (F3 of ~28 Hz)

Specifications:

• RE(ohms): 5.83
• Fs(Hz): 37.42
• Zmax(ohms): 53.63
• Qes: 0.70
• Qms: 5.71
• Qts: 0.62
• Le(mH @ 1kHz): 4.79
• Diam(mm): 333.3750
• BL: 29.16
• Mms: 431.95
• Cms: 41.89
• Sens(@1w/1m): 87.08
• Weight: 40LB