{"product_id":"800-series-818f-d2-18-inch-dual-2-ohm-subwoofer","title":"800 Series 818f-D2 18-Inch Dual 2-Ohm Subwoofer","description":"The DD Audio 818f-D2 is part of the 800 Series, offering extreme Power Tuned Subwoofers engineered for outstanding power handling and competitive bassheads. This 'f' revision includes significant thermal cooling enhancements and cutting-edge design work.\n\nThe 'f' revision subwoofers feature improved thermal transfer through a Dual Stage Aluminum Heat Sink, which conducts heat away from components into open chambers. The Free Flow Cooling System then expels this heat using cooler inducted air.\n\nTo increase Xmax and excursion, the voice coil winding has been lengthened, keeping more coil wire in the gap. This increased coil wire, surrounded by motor steel and billet aluminum, pulls more heat away from the coil, optimizing electrical efficiency during long-term use. Taller surrounds have been tooled and the spider refined to fully optimize the new motor design, with the surrounds double-stitched to fiberglass-loaded non-pressed cones. Double layer, multiple spiders ensure long-term durability.\n\nKey specifications include an 18-inch size, a 4-inch voice coil made in the USA, dual 2-ohm impedance, and an alucast frame. Power handling is rated at 2500W RMS and 7500W Peak. The mounting diameter is 416.9 mm, and the mounting depth is 317.5 mm. Mechanical excursion (x-mech) is 100 mm, and maximum excursion (x-max) is +- 31 mm. The resonant frequency (fs) is 27 Hz, with a Qts of 0.7899 and a Vas of 155.3 Liters. A recommended ported enclosure is between 142-198 liters (net), with no recommended sealed enclosure.","brand":"DD Audio","offers":[{"title":"Default Title","offer_id":52687662285112,"sku":"850054251381","price":899.11,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0970\/4895\/3144\/files\/662653905.jpg?v=1784885812","url":"https:\/\/store.motormia.co\/products\/800-series-818f-d2-18-inch-dual-2-ohm-subwoofer","provider":"MOTORMIA","version":"1.0","type":"link"}