{"product_id":"soundqubed-hdx4-2-series-18-subwoofer-4-dvc-4-000-watts-rms-d2-d4","title":"Soundqubed HDX4.2 Series 18\" Subwoofer 4\" DVC 4,000 Watts RMS D2\/D4","description":"\u003ch2\u003e\u003cstrong\u003eSoundQubed HDX4.2-18 — 4,000W RMS Competition-Grade 18\" Subwoofer\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eSoundQubed HDX4.2 Series 18\" subwoofer\u003c\/strong\u003e is the largest and most powerful driver in the HDX4.2 lineup — a full-size, competition-ready 18-inch subwoofer built for builders who want maximum cone area, infrasonic bass extension, and the kind of low-end output that physically moves air and people. Rated at \u003cstrong\u003e4,000 watts RMS and 8,000 watts peak\u003c\/strong\u003e, the HDX4.2-18 is powered by a \u003cstrong\u003e402 oz magnet\u003c\/strong\u003e, a \u003cstrong\u003e4-inch diameter voice coil\u003c\/strong\u003e with a 70mm coil length, and a motor assembly engineered for extreme linear excursion across a massive \u003cstrong\u003e1,200 cm² cone area\u003c\/strong\u003e. Available in \u003cstrong\u003eDual 2 Ohm (D2)\u003c\/strong\u003e and \u003cstrong\u003eDual 4 Ohm (D4)\u003c\/strong\u003e configurations, this sub is built for wall builds, trunk builds, and any application where maximum displacement and infrasonic output are the goal.\u003c\/p\u003e\n\n\u003cp\u003eWith an \u003cstrong\u003eXmax of 23mm (±)\u003c\/strong\u003e and \u003cstrong\u003eXmech of 47mm (±)\u003c\/strong\u003e, the HDX4.2-18 delivers controlled linear excursion across its enormous cone area, producing authoritative sub-bass extension down to a \u003cstrong\u003efree-air resonance (Fs) of 31.6 Hz (D2) \/ 31.7 Hz (D4)\u003c\/strong\u003e. With sensitivity ratings of \u003cstrong\u003e90.3–90.4 dB\u003c\/strong\u003e, this is the most efficient driver in the HDX4.2 lineup — capable of producing serious SPL output even on moderate amplifier power, and absolutely devastating when fed its full 4,000W RMS rating.\u003c\/p\u003e\n\n\u003ch2\u003eWhy Choose the SoundQubed HDX4.2-18?\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e4,000W RMS \/ 8,000W Peak Power:\u003c\/strong\u003e Handles extreme amplifier output without flinching — built for high-power mono block amplifiers in daily and competition installs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e402 oz Magnet Assembly:\u003c\/strong\u003e Massive motor force delivers exceptional BL (17.8 N\/A D2 \/ 23.3 N\/A D4) for precise, controlled cone movement at high excursion levels.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e4\" Voice Coil, 70mm Coil Length:\u003c\/strong\u003e Extended coil length maximizes gap interaction for superior thermal management and sustained high-power performance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1,200 cm² Cone Area (SD):\u003c\/strong\u003e The largest cone in the HDX4.2 lineup — maximum air displacement for the deepest, most physical sub-bass output.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e23mm Xmax \/ 47mm Xmech:\u003c\/strong\u003e Exceptional linear and mechanical excursion — deep, authoritative bass without bottoming out.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDual 2 Ohm \u0026amp; Dual 4 Ohm Available:\u003c\/strong\u003e Wire D2 to 1Ω or 4Ω, wire D4 to 2Ω or 8Ω — maximum flexibility for any amplifier's stable impedance load.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePorted Enclosure Optimized:\u003c\/strong\u003e Recommended ported volume 5–7 ft³ and sealed 3.0–5.75 ft³ — built to breathe and move in a large, properly tuned vented box.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e90.3–90.4 dB Sensitivity:\u003c\/strong\u003e The most efficient driver in the HDX4.2 lineup — gets devastatingly loud without demanding every last watt from your amplifier.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eAmplifier \u0026amp; Enclosure Recommendations\u003c\/h2\u003e\n\u003cp\u003eThe HDX4.2-18 is designed to be paired with a high-output \u003cstrong\u003emono block amplifier\u003c\/strong\u003e capable of delivering 4,000W RMS or more at the wired impedance load. For the \u003cstrong\u003eD2 (Dual 2 Ohm)\u003c\/strong\u003e variant, wire the coils in parallel for a \u003cstrong\u003e1Ω final load\u003c\/strong\u003e or in series for \u003cstrong\u003e4Ω\u003c\/strong\u003e. For the \u003cstrong\u003eD4 (Dual 4 Ohm)\u003c\/strong\u003e variant, wire in parallel for \u003cstrong\u003e2Ω\u003c\/strong\u003e or in series for \u003cstrong\u003e8Ω\u003c\/strong\u003e. Most high-power Class D mono amps are stable at 1Ω, making the D2 the most common choice for single-sub builds.\u003c\/p\u003e\n\u003cp\u003eFor enclosures, a \u003cstrong\u003eported box tuned to 28–34 Hz\u003c\/strong\u003e in the \u003cstrong\u003e5–7 ft³ range\u003c\/strong\u003e will maximize SPL output and infrasonic bass extension. The HDX4.2-18 is optimized for ported loading — its large cone area and long-throw suspension need room to breathe. A sealed enclosure in the \u003cstrong\u003e3.0–5.75 ft³ range\u003c\/strong\u003e can work for tighter, more controlled bass in applications where ported isn't practical.\u003c\/p\u003e\n\n\u003ch2\u003eElectro Acoustic Specifications \u0026amp; Thiele Small Parameters\u003c\/h2\u003e\n\u003cdiv style=\"overflow-x:auto;\"\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse;font-size:14px;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background-color:#222;color:#fff;\"\u003e\n\u003cth style=\"padding:8px;border:1px solid #ccc;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003eHDX4.2-18D2\u003c\/th\u003e\n\u003cth style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003eHDX4.2-18D4\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eWoofer Size\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e18\"\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e18\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color:#f2f2f2;\"\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eRMS Power\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e4,000 W\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e4,000 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003ePeak Power\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e8,000 W\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e8,000 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color:#f2f2f2;\"\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eMagnet Weight\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e402 oz\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e402 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eCoil Diameter\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e4 in\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e4 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color:#f2f2f2;\"\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eCoil Length\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e70 mm\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e70 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eFs\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e31.6 Hz\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e31.7 Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color:#f2f2f2;\"\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eImpedance\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e2+2 Ohm\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e4+4 Ohm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eQMS\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e3.56\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e3.30\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color:#f2f2f2;\"\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eQES\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e0.52\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e0.55\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eQTS\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e0.45\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e0.47\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color:#f2f2f2;\"\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eVAS\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e114.0 L\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e113.2 L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eLe\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e0.99 mH\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e1.65 mH\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color:#f2f2f2;\"\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eη (No)\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e0.67%\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e0.63%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eCMS\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e0.06 mm\/N\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e0.06 mm\/N\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color:#f2f2f2;\"\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eSensitivity (1W\/1M)\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e90.3 dB\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e90.4 dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eBL\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e17.8 N\/A\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e23.3 N\/A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color:#f2f2f2;\"\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eXmax (±)\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e23 mm\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e23 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eXmech (±)\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e47 mm\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e47 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color:#f2f2f2;\"\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eSD\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e1,200 cm²\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e1,200 cm²\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eMounting Dimensions\u003c\/h2\u003e\n\u003cdiv style=\"overflow-x:auto;\"\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse;font-size:14px;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background-color:#222;color:#fff;\"\u003e\n\u003cth style=\"padding:8px;border:1px solid #ccc;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003eA\u003c\/th\u003e\n\u003cth style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003eB\u003c\/th\u003e\n\u003cth style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003eC\u003c\/th\u003e\n\u003cth style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003eD\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eHDX4.2-18D2\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e465 mm \/ 18.3\"\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e425 mm \/ 16.73\"\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e260 mm \/ 10.24\"\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e288 mm \/ 11.34\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color:#f2f2f2;\"\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eHDX4.2-18D4\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e465 mm \/ 18.3\"\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e425 mm \/ 16.73\"\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e260 mm \/ 10.24\"\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e288 mm \/ 11.34\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eEnclosure Suggestions\u003c\/h2\u003e\n\u003cdiv style=\"overflow-x:auto;\"\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse;font-size:14px;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background-color:#222;color:#fff;\"\u003e\n\u003cth style=\"padding:8px;border:1px solid #ccc;text-align:left;\"\u003eEnclosure Type\u003c\/th\u003e\n\u003cth style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003eHDX4.2-18 D2\/D4\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003eSealed Enclosure\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e3.0–5.75 ft³\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color:#f2f2f2;\"\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;\"\u003ePorted Enclosure\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #ccc;text-align:center;\"\u003e5–7 ft³\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eWhat amplifier do I need for the SoundQubed HDX4.2-18?\u003c\/strong\u003e\u003cbr\u003eYou need a mono block amplifier rated at \u003cstrong\u003e4,000W RMS or more\u003c\/strong\u003e at your wired impedance. The D2 wired to 1Ω is the most common pairing. Look for a high-current Class D mono amp stable at 1Ω for best results.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eShould I choose the D2 or D4 version?\u003c\/strong\u003e\u003cbr\u003eChoose \u003cstrong\u003eD2 (Dual 2 Ohm)\u003c\/strong\u003e if your amplifier is stable at 1Ω (parallel) or 4Ω (series) — this is the most common configuration. Choose \u003cstrong\u003eD4 (Dual 4 Ohm)\u003c\/strong\u003e if your amp is stable at 2Ω (parallel) or you need an 8Ω final load (series).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat size box does the HDX4.2-18 need?\u003c\/strong\u003e\u003cbr\u003eFor \u003cstrong\u003eported\u003c\/strong\u003e, use \u003cstrong\u003e5–7 ft³\u003c\/strong\u003e tuned to approximately 28–34 Hz for maximum SPL and infrasonic bass extension. For \u003cstrong\u003esealed\u003c\/strong\u003e, use \u003cstrong\u003e3.0–5.75 ft³\u003c\/strong\u003e for tighter, more controlled bass.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan this subwoofer handle daily use or is it competition-only?\u003c\/strong\u003e\u003cbr\u003eThe HDX4.2-18 is built for both. Its 90.3–90.4 dB sensitivity — the highest in the HDX4.2 lineup — means it gets devastatingly loud even on moderate power, while its 4,000W RMS rating and 402 oz motor make it a serious competition contender.\u003c\/p\u003e","brand":"SoundQubed","offers":[{"title":"Dual 2 Ohm","offer_id":43669560492099,"sku":null,"price":929.95,"currency_code":"USD","in_stock":true},{"title":"Dual 4 Ohm","offer_id":43669560524867,"sku":null,"price":929.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0637\/9575\/7123\/files\/SoundqubedHDX4.218inSubwooferTrinityCarAudio.png?v=1786637154","url":"https:\/\/www.trinitycaraudio.com\/products\/soundqubed-hdx4-2-series-18-subwoofer-4-dvc-4-000-watts-rms-d2-d4","provider":"Trinity Car Audio","version":"1.0","type":"link"}