Brand NEW! Including 90 Days USA Factory Warranty. Dayton Audio's DMA90-PR 3-1/2" aluminum cone passive radiator allows you to tune small enclosures lower than possible using conventional ports. Matching the DMA series of drivers drivers perfectly, this passive radiator is perfect for use in ultra-small designs like smart speakers, sound bars, and portable Bluetooth speakers. Key Features ? Perfect match for the Dayton Audio DMA series drivers ? Allows tuning small enclosures lower than possible using conventional ports ? Rear mounted threaded post allows easy mass adjustment for custom tuning ? DIY friendly, oversized mounting flange makes installation simple The DMA90-PR 3-1/2" passive radiator from Dayton Audio is the perfect option for achieving low tuning frequencies from the smallest enclosure designs. This incredibly small passive radiator has all the features you would expect lager units including adjustable mass, aluminum cone, and rubber surround. Visually identical to Dayton Audio's full-range DMA series drivers, the DMA90-PR can also be used with any small driver that requires a low tuning frequency. The threaded rod and included wing nut on the back of the cone makes it easy to add mass to tune the radiator as needed for your projects. Whether you are building a smart speaker, sound bar, or portable Bluetooth speaker, the Dayton Audio DMA90-PR introduces a new range of possibilities. Specifications: ? Fs: 38.0 Hz ? Vas: 0.082 ft (2.32 liters) ? Qms: 5.01 ? Cms: 1.10 mm/N ? Mms: 15.9 g ? Rms: 0.76 kg/s ? Sd: 38.5 cm ? Xmech: 8 mm ? Dimensions: Overall diameter: 3.54" x 3.54", Cutout diameter: 3.29", Depth: 1.85". 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 3-1/2" Bolt Circle Diameter 4.25 Moving Mass Of Diaphragm (Mmd) 15.9 Thiele-Small Parameters Resonant Frequency (Fs) 38Hz Mechanical Q (Qms) 5.01 Compliance Equivalent Volume (Vas) 0.082ft Mechanical Compliance of Suspension (Cms) 1.1mm/N Maximum Linear Excursion (Xmax) 8mm Surface Area of Cone (Sd) 38.5cm Materials of Construction Cone Material Aluminum Basket / Frame Material Polymer Mounting Information Overall Outside Diameter 3.54" x 3.54" Baffle Cutout Diameter 3.29" Depth 1.85" # Mounting Holes 4 - All international buyers are responsible for all tax, duties and/or customs fees.