Eric Olson has a faq dealing with amplification and other issues here
. In answer to the question: "How much amplification do I need for powering my tactile transducers?", he says:
"Not much. Despite manufacturers specs on the order of a hundred or more watts per transducer, this much is actually dangerous. It is the same problem with speaker drivers at low frequencies but worse since transducers don't have the air spring to fight against. The situation is not a RMS limited
problem but instead a displacement (excursion) based problem. Manufacturers claim high wattage numbers inorder to sound impressive. If you equalize your transducers then even more of a burden is placed on the low frequencies (20-35Hz). I recommend 20W per transducer as a good number. A transducer bottoming out sounds worse than amplifier clipping. You can use more wattage per transducer but more attention to clipping will be required. This might be a good application for a tube amp or a soft/smooth clipping amplifier. 100W per transducer is just plain overkill."