{"product_id":"polk-audio-db521-5-25-inch-coaxial-silver-speakers-clear-sound","title":"Polk Audio DB521 5.25-Inch Coaxial Speakers (Pair) - Marine Ready","description":"\u003cp\u003eOur review of the Polk Audio DB521 5.25-in coaxial speakers finds them best suited to buyers who want reliable, marine-certified audio that fits common car and boat installations. The single biggest reason to buy is their combination of a mica-filled polymer cone and liquid-cooled silk\/polymer tweeter, which together deliver clear highs and surprisingly full midbass with low distortion even at higher volumes. These speakers are efficient, easy to install, and built to resist sun and salt exposure, making them a practical choice for both vehicle and marine use.\u003c\/p\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMarine certification:\u003c\/strong\u003e The speakers are built to withstand moisture and UV exposure, so they hold up in boat environments and protected outdoor installations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDynamic Balance cone:\u003c\/strong\u003e The polymer\/mica composite woofer provides a stiff but lightweight diaphragm for punchy midbass and reduced distortion.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLiquid-cooled dome tweeter:\u003c\/strong\u003e The 19mm silk\/polymer tweeter with a neodymium magnet yields clear, detailed highs and controlled roll-off.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower handling:\u003c\/strong\u003e Rated to 135 watts maximum input (275 watts peak per pair), they run efficiently and perform well with lower-wattage head units.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShallow mount and multi-hole pattern:\u003c\/strong\u003e The shallow depth and common mounting pattern allow drop-in replacement into many vehicle speaker locations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDurable surround and fasteners:\u003c\/strong\u003e Butyl rubber surrounds and sturdy hardware keep the speakers stable under temperature and weather stress.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThese speakers are ideal for car or boat owners who want an upgrade over factory speakers without changing enclosures. Their marine certification and durable surrounds make them especially useful for small boats, pontoons, and open-deck applications where exposure to sun and spray is a concern.\u003c\/p\u003e\n\u003cp\u003eThey are less suitable for audiophiles chasing extreme low-frequency output or those who need component systems with separate crossovers; for deeper bass a dedicated subwoofer or larger component set will be necessary.\u003c\/p\u003e\n\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eMarine-certified construction provides real durability for boat use and harsh environments.\u003c\/li\u003e\n\u003cli\u003eClear highs from the 19mm liquid-cooled silk\/polymer tweeter keep vocals and cymbals detailed.\u003c\/li\u003e\n\u003cli\u003eFitment-friendly shallow depth and multi-hole mounting pattern make installation straightforward in many vehicles.\u003c\/li\u003e\n\u003cli\u003eGood value and efficient output; performs well even with lower-power head units.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eAs coaxials, they offer limited low-end extension compared with larger woofers or component systems.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eDriver size\u003c\/td\u003e\n\u003ctd\u003e5.25 in (5 1\/4 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConfiguration\u003c\/td\u003e\n\u003ctd\u003e2-way coaxial\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTweeter\u003c\/td\u003e\n\u003ctd\u003e19mm liquid-cooled silk\/polymer dome with neodymium magnet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower handling\u003c\/td\u003e\n\u003ctd\u003eMaximum input 135 watts each; 275 watts peak per pair; RMS 90 watts per pair (45W each)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCone material\u003c\/td\u003e\n\u003ctd\u003eDynamic Balance polymer\/mica composite mineral filled cone\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurround\u003c\/td\u003e\n\u003ctd\u003eDurable butyl rubber\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eShallow depth with multi-hole mounting pattern for drop-in installs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eThe Polk DB521 5.25-in coaxial speakers are a practical, durable upgrade for drivers and boat owners who need reliable, clear sound without complex installation. They deliver well-defined highs and respectable midbass from a compact package, and their marine rating and efficient design make them a strong value for mixed vehicle and marine use.\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eAre these speakers suitable for boats?\u003c\/strong\u003e\u003cbr\u003eYes; they are marine certified and built with durable surrounds and finishes that resist sun and moisture exposure.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill they work with a low-power head unit?\u003c\/strong\u003e\u003cbr\u003eYes; the high efficiency design performs acceptably with lower-wattage head units and does not require a high-power amplifier for everyday listening.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDo they require new mounting holes?\u003c\/strong\u003e\u003cbr\u003eThe speakers use a multi-hole mounting pattern and shallow depth to fit many factory locations and often use existing screw holes for easier installation.\u003c\/p\u003e","brand":"Polk Audio","offers":[{"title":"Default Title","offer_id":46751982125275,"sku":"B000P0PF8C","price":42.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/610H6nP2DqL._AC_SL1000.jpg?v=1747804474","url":"https:\/\/gearmusthave.com\/products\/polk-audio-db521-5-25-inch-coaxial-silver-speakers-clear-sound","provider":"GearMustHave","version":"1.0","type":"link"}