Sundown Audio SA-18 REV3 D4 18" 750 Watts RMS Dual 4-Ohm SA Series Subwoofer

The SA series was designed to be an excellent sounding subwoofer that is equally at home sealed or ported. We feel that the SA series is one of the best woofers available in it's price category and will satisfy the needs of a wide variety of users ranging from bass-heads to audiophiles! The SA series is also gaining popularity in SPL competitions due to their excellent voice coil cooling and rugged, durable constructions with several customers achieving output well over 150 dB!

The Sundown SA series woofers represent the result of several years of testing and R&D into making the most rugged, longest lasting, and best sounding subwoofers possible in their price range. Not only do the SA series drivers have the capacity for extremely high output on the street and in the SPL lanes but they are also designed with low distortion in mind via their high linear excursion and dual faraday rings. The SA line has consistently proven itself to customers in the USA and worldwide both on the streets and in the SPL lanes since their introduction in mid-2009.

The SA line was designed to be the centerpiece of the Sundown Audio subwoofer lineup -- the line to which all of our other lines are compared. We started with an FEA optimized motor design capable of 19mm of one-way Klippel verified excursion and significantly more x-mech (maximum mechanical excursion). This motor was mated to a top quality double layer nomex spider, an SPL competition grade paper cone, and a strong foam surround capable of handling the excursion and force generated by the motor structure. The motor also features dual faraday rings (shorting rings) to reduce inductive distortion. At Sundown Audio this still was not enough so we designed a highly optimized voice coil cooling system that ensures that an SA series woofer will never over-heat when used anywhere close to it's rated power level. This system allows our 2.5" coil to match and exceed the thermal performance of many 3" coil drivers on the market today. This same voice coil cooling system has been applied to all of our larger woofers lines as well due to it's proven effectiveness over the years in the SA series.

All of this hard work and engineering has lead to the incredible reputation now enjoyed by the SA series worldwide. We are very proud of what these woofers are capable of and we believe that they are one of the best woofers on the market today in their price and power range.

• Power Handling:
• RMS: 600W
• Voice Coil Configuration: Dual 4 ohm
• 19.0mm X‐Max by 70% BL method one‐way (38.0mm peak to peak)
• Thick black anodized aluminum voice coil formers for maximum strength and heat dissipation
• 4‐layer copper high temperature voice coil windings with 45mm winding length
• Double layer permanently bonded high strength Nomex spider pack for maximum longevity and durability
• Thick flat tinsel lead wires tied down to the spider to prevent lead noise and breakage
• Custom tooled triple joint support ring
• Custom tooled frame spacer / ventilation ring
• High efficiency air‐flow management integrated into the motor for maximum voice coil cooling
• Dual Aluminum Faraday rings for reduced inductance and inductive distortion (pole cap and magnet ID)
• Recommended Box Specs (Sealed): 3.5 ft^3 (Yields F3 of 41Hz)
• Recommended Box Specs (Ported): 5 ft^3 (Tune to 35Hz, Yields F3 of 28Hz)
• Recommended 70 Square Inches of Port Area at 26" port length.

Product Specifications:

• RE (ohms): 4.61
• FS (Hz): 34.88
• Vas (L): 54.69
• Qes: 0.72
• Qms: 6.52
• Qts: 0.65
• Le (mH): 3.39
• BL (NA): 21.76
• Mms (Grams): 338
• Cms (uM/N): 61.42
• Sens (1w/1m): 86.81
• Cutout Diameter: TBA
• Mounting Depth: TBA
• Overall Diameter w/ Gasket: TBA
• Displacement: 0.17ft^3

NOTE: Specifications are measured after about 5 minutes of break-in time. You will see the CMS loosen up another 33% after some serious play time which will both reduce the FS and Qts figures of the drivers. Some Re variance is shown based on coil temperature from break-in period. D2 is closer to 4.0 in series and D4 7.0 in series at room temperature. This does not affect box calculations.

Box specifications are suggestions – other volumes and tunings can be used based on the needs of your application. The SA series woofers are compatible with most quality pre-fabricated enclosures as well. They also lend themselves favorably to fourth order band-pass enclosures.