Subwoofer Reviews

Description: Stereo dipole subwoofer system with active electronic crossover. Driver complement: two 8" woofers per side in free-air enclosure. Includes protection for ESL and the facility to adjust the ESL level with a series resistor. Active electronic crossover with two midrange adjustment curves, stereo or mono-sum signal outputs, and continuously variable subwoofer output; available with single-ended RCA inputs and outputs, or balanced XLR configuration. Crossover frequency: 150Hz. Input impedance: 22k ohms. Output impedance: 1k ohm for the Quad ESL amplifier, 1–3k ohms for the subwoofer amplifier, depending on level control. Crossover S/N ratio: >105dB. Separation: >65dB at 15kHz.
Dimensions: 20.9" (530mm) W by 10.25" (260mm) H by 5.9" (150mm) D. Height with ESLs: 37.4" (950mm). Weight: 20 lbs (9.1kg). Electronic crossover dimensions: 7.2" (182mm) W by 2" (50mm) H by 5.1" (130mm) D. Weight: 1.5 lbs (700gm).
Serial numbers of samples tested: 0021A/B (subwoofer); 21 & 25 (crossover).
Price: $1995 with unbalanced crossover, $2100 balanced (1994); no longer available (2010). Approximate number of dealers: 30.
Manufacturer: Gradient Ltd., Levysepänkatu 28, 04440 Järvenpää, Finland. Tel: (358) 50-384-48-69. Web: www.gradient.fi. US distributor: Quad USA, Barrington, IL 60010 (1994); SimpliFi Audio, California Suites Apt. 1001, 5415 Clairmount Mesa Blvd., San Diego, CA 92117 (2010). Tel: (724) 712-0899. Web: www.simplifiaudio.com.