Hello everyone, I am planning a prototype project and could really use a little help with the feasibility. The idea is to use haptic feedback to communicate a variety of frequencies through a material so that audience members can "hear" them with their hands. If I wanted to excite a metal plate or tube at a variety of different frequencies without any audible sound, what would be the best way to do it? I have found this: http://www.precisionmicrodrives.com/new-vibration-motors/310-101-10mm-coin-vibrator-motor
but it only vibrates at 183hz, I'll need a broader range of frequencies to make my project effective. It would also be desirable to effect the amplitude of the resulting vibrations. Do you think this is feasible? Many thanks in advance.