Stereo Integrity SQL Series 2 – 15″ Subwoofer The SQL series stands as our best-ever produced subwoofer when it comes to performance-to-cost ratio. It’s engineered to offer a solid Sound Quality (SQ) foundation, complemented by the potential for gut-wrenching bass when needed. The SQL series, fully designed using Finite Element Analysis (FEA) simulation software, embodies its name, delivering Sound Quality Loud. The motor topology of our SQL series is based on an SGLC overhung design. It employs a solid copper winding 2.75″ voice coil, which is wound on a split black anodized aluminum former. The choice of a 2.75″ diameter coil strikes the perfect balance between 2.5″ and 3.0″ coil diameters – it maintains less inductance than a 3″ coil while offering more motor force than a 2.5″ coil. The coil and overall mass balance have been meticulously calculated and verified through multiple Klippel test sessions, resulting in a 50 mm winding width coil (voice coil winding height). Nested inside the Y35 grade magnet structure, you’ll find a solid aluminum faraday ring that reduces inductance for enhanced transient attack characteristics. Our SQL series is equipped with large 8 3/8″ dual Nomex spiders. They offer a uniform suspension compliance curve that minimizes suspension distortion over the linear stroke. These spiders are designed to stiffen up at or near the limits of Xmax to handle extra excursion when necessary. Dual mirror flat woven lead wires, sewn onto the top of the spider, ensure symmetrical compliance on both sides, effectively eliminating the coil rocking issues associated with single leaded spiders. On the exterior, a stiff naturally dried, treated paper cone and tall roll rubber surround grace the top of the SQL series subwoofer. The paper pulp cone brings the ideal mass for improved low-frequency reproduction, while the tall rubber surround harmoniously complements the dual Nomex spiders, creating a perfectly balanced suspension curve. Click on the white BL/Kms plot adjacent to the subwoofer images to view the Klippel results. Finally, the design of the enclosure and the overall performance of the SQL series cannot be overlooked. These subwoofers can operate efficiently in a very small sealed enclosure or in small to medium-sized vented enclosures. The low F3 points in the sealed enclosures of the SQL series enable them to play down to 8 Hz, making them unrivaled low-end performers even in compact sealed boxes. The immaculate output capability at full volume is directly attributed to their 28 mm one-way linear Xmax. In sum, our SQL series subwoofers readily deliver clean, loud, and broad bandwidth performance, even in small enclosures. Elevate your audio experience with the SQL series. Subwoofers Specifications Quick Info Weight 28 lbs Dimensions (OD) 15.375 inches Dimensions (Cutout) 14.20 inches Mounting Depth 7.4 inches Displacement 0.16 cubic feet RMS 1000 watts Materials Voice Coil Material copper Thiele-Small Parameters Re 3.25 Ohms Fs 23.8 Hz Qes 0.45 – Qms 5.83 – Qts 0.42 – Le 2 mH Sd 130.17 square inches Vas 115 Liters BL 20.417 Tesla Meters Mms 388.55 grams Cms 115 µM/N Xmax 28.4 mm one-way 70% BL SPL 87.4 dB Enclosure Recommendations Sealed Enclosure Volume 2 cubic feet Ported Enclosure Volume 4.25 cubic feet Ported Enclosure Tuning 22 Hz Port Surface Area 20 square inches Additional Specifications Distance from baffle to top of surround 1.25 inches Minimum clearance from top of surround to speaker grill .05 inches Additional information Impedance Dual 2 ohm, Dual 4 ohm Dust Cap Material Paper, Carbon Fiber
