Brand NEW! Including 90 Days USA Factory Warranty. The Dayton Audio Designer Series passive radiators are excellent general-purpose passives suitable for replacement or for new construction. Built to be a perfect match for the Designer Series drivers, these passive radiators feature the same steel frame, rubber surround, and anodized aluminum cone making them visually identical. Key Features Perfect match for Dayton Audio's aluminum cone Designer Series drivers Allows tuning small enclosures lower than using conventional ports Rear mounted screw allows easy mass adjustment for custom tuning Cosmetic frame edge looks great even when surface mounted The Dayton Audio Designer Series passive radiators are excellent general-purpose passives 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, these passives match Dayton Audio's Designer Series drives, with a black anodized aluminum cone and medium-roll rubber surround for clean excursion and long life. The possibilities with these passives are endless, from stand mount two-ways to portable battery powered speaker systems. Specifications: ? Fs: 27.9 Hz ? Vas: 0.43 ft ? Qms: 3.7 ? Cms: 1.51 mm/N ? Rms: 1.0 kg/s ? Mms: 21.5 g ? Sd: 75.4 sq. cm. ? Xmax: 8 mm ? Dimensions: Overall diameter: 5.31", Cutout diameter: 4.40", Depth: 1.5". Note: Adding mass to the passive radiator will decrease Fs and increase Qms. Tip: As a general rule, the passive radiator(s) should have at least double the displacement of air (Vd) as the active woofer(s)/subwoofer(s) in the system. To calculate Vd: Sd x Xmax = Vd Product Specifications Nominal Diameter 5" Bolt Circle Diameter 4.21 Moving Mass Of Diaphragm (Mmd) 21.5 Thiele-Small Parameters Resonant Frequency (Fs) 27.9Hz Mechanical Q (Qms) 3.7 Compliance Equivalent Volume (Vas) 0.43ft Mechanical Compliance of Suspension (Cms) 1.51mm/N Maximum Linear Excursion (Xmax) 8mm Surface Area of Cone (Sd) 75.4cm Materials of Construction Cone Material Aluminum Surround Material Rubber Basket / Frame Material Steel Mounting Information Overall Outside Diameter 5.31" Baffle Cutout Diameter 4.40" Depth 1.5" # Mounting Holes 4 - All international buyers are responsible for all tax, duties and/or customs fees.