Dayton Audio HDN-8B Weatherproof Sound Exciter

Compact and extremely versatile, the HDN-8B Sound Exciter Transducer lets you create high-quality `hidden speakers' in walls, ceilings, floors, furniture, seating, displays, and virtually any other surface you can think of resulting in a truly invisible sound source. The ...Compact and extremely versatile, the HDN-8B Sound Exciter Transducer lets you create high-quality `hidden speakers' in walls, ceilings, floors, furniture, seating, displays, and virtually any other surface you can think of resulting in a truly invisible sound source. The integrated M5 threaded mounting stud makes the HDN-8B perfect for installation onto thin hard surfaces like acrylic, fiberglass, and metal.

For wooden, plastic, or composite surfaces the HDN-8 (coarse threaded post) may be a better choice.