The Dayton Audio DAEX32QMB-4 4 ohm 40 watt sound exciter improves power handling with a vented voice coil. Turns almost anything with a flat surface into a speaker.

Dayton Audio's DAEX32QMB-4 quad arm exciter is built with four arms that extend out from the main exciter body, which allows this exciter to transfer sound to a much larger surface for lower frequency response extension (more bass). Also, the arms help to support the magnet/voice coil improving linearity when mounted on vertical surfaces. 

• 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 audio amplifiers, without sacrificing total output.
• The 1.25" voice coil allows for more input power, creating rich, dynamic sound. 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, and the four arms ... just peel and stick

Features

• Large 32 mm voice coil improves power handling to 40 watts RMS
• Rare-earth neodymium motor and a proprietary vented voice coil 32mmØ
• Four arms provide extra support improving linearity on larger surfaces
• Turns any flat, rigid surface into a speaker
• Optimised for a lower Fs of 480Hz
• Usable bandwidth 90Hz to 6KHz (Dependent on surface material)