{"product_id":"rcf-lf21n451-woofer","title":"RCF LF21N451 Woofer","description":"\u003cdiv\u003eThe \u003cspan style=\"font-weight: bold;\"\u003eLF21N451\u003c\/span\u003e 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.\u003c\/div\u003e \u003cdiv\u003e \u003c\/div\u003e \u003cdiv\u003eThe 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. \u003c\/div\u003e \u003cdiv\u003e \u003c\/div\u003e \u003cdiv\u003eThe 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\/div\u003e \u003cdiv\u003e \u003c\/div\u003e \u003cdiv\u003e\u003cspan style=\"font-weight: bold; text-decoration: underline;\"\u003eFeatures\u003c\/span\u003e\u003c\/div\u003e \u003cdiv\u003e \u003cul\u003e \u003cli\u003e4,5 - inch Inside\/Outside copper voice coil\u003c\/li\u003e \u003cli\u003e3000 Watt continuous program power handling\u003c\/li\u003e \u003cli\u003e98.5 dB Sensitivity\u003c\/li\u003e \u003cli\u003e30 Hz - 1 kHz Frequency range\u003c\/li\u003e \u003cli\u003eDual-forced air ventilation for minimum power compression\u003c\/li\u003e \u003cli\u003eDual spider designed with silicon based damping control\u003c\/li\u003e \u003cli\u003eBL of 34.5 Txm to provide a faster and accurate low frequency\u003c\/li\u003e \u003c\/ul\u003e \u003c\/div\u003e \u003cdiv\u003e\u003cspan style=\"font-weight: bold; text-decoration: underline;\"\u003eSpecifications\u003c\/span\u003e\u003c\/div\u003e \u003cdiv\u003e \u003cul\u003e \u003cli\u003eNominal Diameter: 530 \/ 21 mm\/inch\u003c\/li\u003e \u003cli\u003eRated Impedance: 8 Ω\u003c\/li\u003e \u003cli\u003eProgram Power: 3000 W AES\u003c\/li\u003e \u003cli\u003ePower handling capacity: 1500 W AES\u003c\/li\u003e \u003cli\u003eSensitivity: 98.5 dB\u003c\/li\u003e \u003cli\u003eFrequency Range: 30 Hz ÷ 1000 Hz\u003c\/li\u003e \u003cli\u003eEffective Piston Diameter: 470 \/ 18.5 mm\/inch\u003c\/li\u003e \u003cli\u003eMax Excursion Before Damage (peak to peak): 58 \/ 2.28 mm\/inch\u003c\/li\u003e \u003cli\u003eMinimum Impedance: 7.1 Ω\u003c\/li\u003e \u003cli\u003eVoice Coil Diameter: 115 \/ 4.5 mm\/inch\u003c\/li\u003e \u003cli\u003eVoice Coil Material: Copper\u003c\/li\u003e \u003cli\u003eVoice Coil Winding Depth: 34 \/ 1.33 mm\/inch\u003c\/li\u003e \u003cli\u003eNumber of layers: 2\u003c\/li\u003e \u003cli\u003eKind of layer: inside \/ outside\u003c\/li\u003e \u003cli\u003eTop Plate Thickness: 15 \/ 0.6 mm\/inch\u003c\/li\u003e \u003cli\u003eCone Material: No pressed pulp carbon fiber reinforced\u003c\/li\u003e \u003cli\u003eCone Design: Curved\u003c\/li\u003e \u003cli\u003eSurround Material: Polycotton\u003c\/li\u003e \u003cli\u003eSurround Design: Triple roll\u003c\/li\u003e \u003cli\u003eDC resistance: 5.6Ω\u003c\/li\u003e \u003cli\u003eMechanical factor: 6\u003c\/li\u003e \u003cli\u003eElectrical factor: 0.27\u003c\/li\u003e \u003cli\u003eTotal factor: 0.26\u003c\/li\u003e \u003cli\u003eBL Factor: 34.5 T · m\u003c\/li\u003e \u003cli\u003eEffective Moving Mass: 315 g\u003c\/li\u003e \u003cli\u003eEquivalent Cas air load: 375 liters\u003c\/li\u003e \u003cli\u003eEffettive piston area: 0.173 m²\u003c\/li\u003e \u003cli\u003eMax. linear excursion (mathematical): 13.2 mm\u003c\/li\u003e \u003cli\u003eVoice - coil inductance @ 1kHz: 3.0 mH\u003c\/li\u003e \u003cli\u003eHalf-space efficiency: 4.0%\u003c\/li\u003e \u003cli\u003eOverall Diameter: 547 \/ 21.5 mm\/inch\u003c\/li\u003e \u003cli\u003eBolt Circle Diameter: 527 \/ 20.7 mm\/inch\u003c\/li\u003e \u003cli\u003eBolt Hole Diameter: 6.5 \/ 0.25 mm\/inch\u003c\/li\u003e \u003cli\u003eFront Mount Baffle Cut-out: 512 \/ 20.1 mm\/inch\u003c\/li\u003e \u003cli\u003eRear Mount Baffle Cut-out: 512 \/ 20.1 mm\/inch\u003c\/li\u003e \u003cli\u003eDepth: 250 \/ 9.8 mm\/inch\u003c\/li\u003e \u003cli\u003eVolume occupied by the driver: 6.5 \/ 0.229 liters\/ft³\u003c\/li\u003e \u003cli\u003eNet Weight: 10.9 \/ 24 kg\/lbs\u003c\/li\u003e \u003c\/ul\u003e \u003c\/div\u003e","brand":"RCF","offers":[{"title":"Default Title","offer_id":32388172480647,"sku":"LF21N451","price":539.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0319\/3687\/2583\/products\/img_proxy_74a00ee0-0474-41d2-8d4d-dec9233321ca.jpg?v=1582296157","url":"https:\/\/www.balkanimal.com\/products\/rcf-lf21n451-woofer","provider":"Audiofeen","version":"1.0","type":"link"}