E 15 v4 D4 | SUNDOWN AUDIO 15 500W RMS DUAL 4 OHM SUBWOOFERS The third version of our acclaimed E series is all new for 2016. Since we introduced the first E series in 2012 we have sought to push the limits of entry level woofers forward. Typical entry level woofers are highly limited in terms of linear excursion, mechanical ruggedness, and thermal performance – all of these bars have been raised once again for our third generation E series. The new stamped steel frame is also significantly stronger than previous generation E series woofers & features an enhanced Sundown style high pressure vented spider landing. Working in conjunction with a motor ventilation system based on our SA series & the new, larger voice coil the third generation E series possesses thermal capacity unheard of in this class of subwoofer. Bottom line; if you are looking for a great subwoofer option and do not want to break the bank the Sundown E Series woofers are for you & these are the best E series made to date. They are ideal for anyone from beginners to seasoned professionals seeking industry leading performance at a value price point. Features & Technology: RMS Power 500 watts Xmax 14mm one way by 70 Percent BL Vented magnetic gap Vented pole piece with optimized geometry Black Aluminum 2.5 voice coil former for superior heat dissipation High Temperature 4 Layer copper voice coil wire Spring Loaded Terminals Stitched On Mini XL Tinsel Leads to prevent fatigue and failure Box Recommendations: Sealed: 2.5 ft^3 Ported: 3.25 ft^3 Displacement: 0.14 ft^3 Depth: 7 1/4 Outside Diameter: 15 1/8 Cut Out: 13-7/8 Recommended Tuning: 32hz Recommended Port Area: 52 in^2