Additional Details ------------------------------ Bullet point: Heavy-duty design with a 32 mm voice coil for a high 20 watt RMS power handling_Pre-applied 3M VHB adhesive for quick, secure installation_Rare-earth neodymium motor and a proprietary two-layer voice coil_4 ohms impedance for use with small, Class D amplifiers_Dimensions: 2.625" (66 mm) overall diameter x 0.75" (19 mm) total height Adhesive dimensions: 1.64" (41.7 mm) outside diameter, 0.86" (21.7 mm) inside diameter Product description: Quick Overview Turn large, rigid surfaces into speakers with the Dayton Audio DAEX32U-4. Includes pre-attached 3M VHB adhesive for maximum energy transfer, even on moving objects! Product Highlights Heavy-duty design with a 32 mm voice coil for a high 20 watt RMS power handling Pre-applied 3M VHB adhesive for quick, secure installation Rare-earth neodymium motor and a proprietary two-layer voice coil 4 ohms impedance for use with small, Class D amplifiers Product Manuals / Spec Sheets / Downloads Dayton Audio DAEX32U-4 Specification SheetBuying Options Buy NowBuy Internationally Product Description Dayton Audios DAEX32U-4 Ultra exciter is built to turn large, thick, rigid surfaces into speakers. The 32 mm voice coil makes it perfect for large glass panes, furniture, and surfaces that would normally resist the effects of an exciter. A neodymium magnet is employed to create maximum magnetic flux around the proprietary voice coil for increased sensitivity when compared to similar sized exciters. In turn, this reduces power requirements and makes it possible to use very small Class D audio amplifiers, without sacrificing total output. To ensure maximum acoustic energy transfer between the transducer and the surface to which it is attached, 3M VHB (Very High Bond) adhesive is pre-applied to the main body... just peel and stick! Two male spade quick-disconnect terminals are built onto the main body for quick electrical connection. Note: An exciters frequency response and sensitivity are completely dependent on the exciters designated surface. Thinner, smaller materials will tend to be louder and create a mid/tweeter response. Thicker, larger materials (with multiple exciters) will be slightly quieter but result in a more full-range sound. Dimensions: 2.625" (66 mm) overall diameter x 0.75" (19 mm) total height Adhesive dimensions: 1.64" (41.7 mm) outside diameter, 0.86" (21.7 mm) inside diameter To understand more about exciter technology, here is a link to the Exciters Buyers Guide . Product Details Speaker Series Exciters Model Number DAEX32U-4 Color Black Unit of Measure Each UPC 848791001925 Warranty - Parts 5 Years Warranty - Labor 5 Years Product Shipping Weight (lbs.) 0.35 Power Handling (RMS) 20 watts Power Handling (max) 40 watts Continuous Program Power -- Impedance 4 ohms Sensitivity -- Frequency Response -- Voice Coil Diameter 32 mm Magnet Weight -- DC Resistance (Re) 3.5 ohms Voice Coil Inductance (Le) 0.23 mH @ 1 kHz Resonant Frequency (Fs) 160 Hz Mechanical Q (Qms) -- Electromagnetic Q (Qes) -- Total Q (Qts) -- Diaphragm Mass Inc. Airload (Mms) -- Moving Mass Of Diaphragm (Mmd) -- Mechanical Compliance of Suspension (Cms) -- Surface Area Of Cone (Sd) -- Volume of Displacement (Vd) -- BL Product (BL) -- Compliance Equivalent Volume (Vas) -- Maximum Linear Excursion (Xmax) -- Drivers Mechanical Losses (Rms) -- Entry / Exit Diameter -- Surround Material -- Voice Coil Wire Material -- Voice Coil Former -- Basket/Frame Material -- Magnet Material -- Overall Outside Diameter -- Overall Depth -- Baffle Cutout Diameter -- Mounting Hole Diameter -- Bolt Circle Diameter -- Product Weight --