{"product_id":"lf21n451","title":"RCF LF21N451 Woofer","description":"\u003cp\u003eThe LF21N451 is a very high power handling and efficiency transducer specially designed to provide powerful and accurate sub-bass frequencies with low distortion and low power compression. The height of the voice coil has been specifically designed to improve the excursion and linearity at very low frequencies. The LF21N451 uses a special RCF developed carbon fibre + nylon + cellulose composite pulp which reinforces and improves the rigidity of the cone structure. The new pulp and the large triple roll surround along double silicon spider system ensure excellent control and makes the cone resistant to deformation caused by very large displacements and pressure created by the transducer's high excursion behaviour. A fully optimised T-pole design generate the minimum amount of flux modulation. The dual-forced air venting system provides a very efficient voice coil ventilation to minimize the power compression.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eFeatures\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e4,5 - inch Inside\/Outside copper voice coil\u003c\/li\u003e\n\u003cli\u003e3000 Watt continuous program power handling\u003c\/li\u003e\n\u003cli\u003e98.5 dB Sensitivity\u003c\/li\u003e\n\u003cli\u003e30 Hz - 1 kHz Frequency range\u003c\/li\u003e\n\u003cli\u003eDual-forced air ventilation for minimum power compression\u003c\/li\u003e\n\u003cli\u003eDual spider designed with silicon based damping control\u003c\/li\u003e\n\u003cli\u003eBL of 34.5 Txm to provide a faster and accurate low frequency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eSpecifications\u003c\/strong\u003e\u003c\/p\u003e\u003ctable\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\"\u003e\u003cstrong\u003eGeneral specifications\u003c\/strong\u003e\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal Diameter\u003c\/td\u003e\n\u003ctd\u003e21 inch \/ 533 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRated Impedance\u003c\/td\u003e\n\u003ctd\u003e8 ohm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProgram Power (watt)\u003c\/td\u003e\n\u003ctd\u003e3000 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower handling capacity\u003c\/td\u003e\n\u003ctd\u003e1500 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSensitivity\u003c\/td\u003e\n\u003ctd\u003e98.5 dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFrequency range\u003c\/td\u003e\n\u003ctd\u003e30 - 1000 Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEffective piston diameter\u003c\/td\u003e\n\u003ctd\u003e470 mm \/ 18.5 inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax. Excursion Before Damage\u003c\/td\u003e\n\u003ctd\u003e58 mm \/ 2.28 inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMinimum Impedance (ohm)\u003c\/td\u003e\n\u003ctd\u003e7.1 ohm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoice Coil Diameter\u003c\/td\u003e\n\u003ctd\u003e4.5 inch \/ 114 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoice Coil Winding Material\u003c\/td\u003e\n\u003ctd\u003eCopper\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoice Coil Length\u003c\/td\u003e\n\u003ctd\u003e34 mm \/ 1.34 inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumber of layers\u003c\/td\u003e\n\u003ctd\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eKind of layers\u003c\/td\u003e\n\u003ctd\u003einside\/outside\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTop Plate Thickness\u003c\/td\u003e\n\u003ctd\u003e15 mm \/ 0.59 inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCone Design\u003c\/td\u003e\n\u003ctd\u003eCurved\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurround Material\u003c\/td\u003e\n\u003ctd\u003ePolycotton\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurround Design\u003c\/td\u003e\n\u003ctd\u003eTriple roll\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMagnets\u003c\/td\u003e\n\u003ctd\u003eNeodymium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDual-force air ventilation\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpider\u003c\/td\u003e\n\u003ctd\u003eDual with silicon based damping control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\"\u003e\u003cstrong\u003eThiele - small parameters\u003c\/strong\u003e\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResonance frequency (Fs)\u003c\/td\u003e\n\u003ctd\u003e30 Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDC resistance (Re) (ohm)\u003c\/td\u003e\n\u003ctd\u003e5.60 ohm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMechanical factor\u003c\/td\u003e\n\u003ctd\u003e6.10 Qms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eElectrical factor\u003c\/td\u003e\n\u003ctd\u003e0.27 Qes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal factor\u003c\/td\u003e\n\u003ctd\u003e0.26 Qts\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBl factor (Bl) (T x m)\u003c\/td\u003e\n\u003ctd\u003e34.50 T x m\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEffective moving mass (Mms)\u003c\/td\u003e\n\u003ctd\u003e315.0 g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEquivalent Cas air loaded (Vas)\u003c\/td\u003e\n\u003ctd\u003e375.0 liters\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEffective piston area (Sd)\u003c\/td\u003e\n\u003ctd\u003e0.170 m2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax. linear excursion (Xmax)\u003c\/td\u003e\n\u003ctd\u003e13 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoice coil inductance @ 1kHz (Le1k)\u003c\/td\u003e\n\u003ctd\u003e3.00 mH\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHalf-space efficency (Eff)\u003c\/td\u003e\n\u003ctd\u003e4.00%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\"\u003e\u003cstrong\u003eMounting information\u003c\/strong\u003e\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOverall diameter\u003c\/td\u003e\n\u003ctd\u003e547 mm \/ 21.54 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBolt circle diameter\u003c\/td\u003e\n\u003ctd\u003e527 mm \/ 20.75 inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBolt hole diameter\u003c\/td\u003e\n\u003ctd\u003e7 mm \/ 0.28 inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFront mount baffle cut-out\u003c\/td\u003e\n\u003ctd\u003e512 mm \/ 20.16 inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRear mount baffle cut-out\u003c\/td\u003e\n\u003ctd\u003e512 mm \/ 20.16 inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVolume occupied by the driver\u003c\/td\u003e\n\u003ctd\u003e6.5 liters \/ 0.26 ft3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\"\u003e\u003cstrong\u003eStandard compliance\u003c\/strong\u003e\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSafety agency\u003c\/td\u003e\n\u003ctd\u003eCE compliant\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\"\u003e\u003cstrong\u003eSize \/ Weight\u003c\/strong\u003e\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHeight\u003c\/td\u003e\n\u003ctd\u003e249 mm \/ 9.8 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiameter\u003c\/td\u003e\n\u003ctd\u003e547 mm \/ 21.54 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e10.9 kg \/ 24.03 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\"\u003e\u003cstrong\u003eShipping information\u003c\/strong\u003e\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePackage Height\u003c\/td\u003e\n\u003ctd\u003e284 mm \/ 11.18 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePackage Width\u003c\/td\u003e\n\u003ctd\u003e584 mm \/ 22.99 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePackage Depth\u003c\/td\u003e\n\u003ctd\u003e604 mm \/ 23.78 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePackage Weight\u003c\/td\u003e\n\u003ctd\u003e13.5 kg \/ 29.76 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e","brand":"RCF","offers":[{"title":"Default Title","offer_id":46528136020165,"sku":"LF21N451","price":969.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0612\/9093\/files\/000_LF21N451_singolo_gallery.png?v=1783905696","url":"https:\/\/www.prodj.com\/products\/lf21n451","provider":"ProDJ","version":"1.0","type":"link"}