The Dayton Audio DS175-PR 6-1/2 passive radiator is excellent general-purpose radiator which allows lower tuning frequencies in smaller enclosures, suitable for replacement or for new construction. Highlights * Long-throw suspension system for clean excursion * Rugged stamped frame design with rear spider for stability * Durable coated paper cone and rubber surround * M5 threaded hole simplifies adding mass for lower tuning frequency Product Details Dayton Audio DS175-PR 6-1/2 Passive Radiator The Dayton Audio DS175-PR 6-1/2 passive radiator is an excellent general-purpose radiator suitable for replacement or for new construction. A built-in mass disc offers a good starting point for most designs, and a convenient M5 threaded hole (screw included) allows different types of weights to be added if desired. Cosmetically and mechanically, the passives match the Designer Series line of drivers, with a poly coated paper cone and medium-roll rubber surround for clean excursion and long life. The possibilities with these passives are endless, from floor standing two-ways to small active/passive subwoofer systems. Recommended for use in passive radiator enclosure alignments with active drivers from 3 to 6.5 in diameter. Dual passive radiators are recommended for use with 6.5 active drivers. Specifications: • Fs: 30.2 Hz • Vas: 0.61 cu. ft. • Qms: 1.8 • Cms: 0.74 mm/N • Mms: 37.5 g • Sd: 128.7 sq. cm. • Xmax: 8 mm • Dimensions: Overall diameter: 6.94, Cutout diameter: 5.63, Depth: 1.88 Note: Adding mass to the passive radiator will decrease Fs and increase Qms. Tip: As a general rule the passive radiator(s) should be able to move double the volume of air as the active woofer(s)/subwoofer(s) in the system. For example: A passive radiator system for a 6-1/2 woofer/subwoofer that has 8 mm of X-max would require 2-6-1/2 passive radiators with 8 mm of X-max. For single passive radiator systems, it is common to use a passive that is larger than the active woofer(s)/subwoofer(s).