A.D.A.M. Audio manufactures or has manufactured the following equipment (click to expand models list):Dynamic Speakers
Adam Audio web site (June 2009): The ART (=Accelerating Ribbon Technology) tweeters and midrange units take a completely new approach in kinematics to move air and improve the quality of music reproduction. Based on the original works of Dr. Oskar Heil, who invented his "Air Motion Transformer" back in 1972, new electroacoustic transducers have been developed that are based on improved layouts and new materials. The membrane consists of a lamella like folded diaphragm whose single folds move according to the alternate current, thus squeezing air in and out.
All other loudspeaker drive units, whether they are voice coil driven, electrostatics, piezos or magnetostatics, act like a piston, moving air in a 1:1 ratio. This is undesirable, as the specific weight of air is much lower than that of the driving mechanics. Speaking in terms of electrical Engineering one could say there is a bad match between source and load. The ART principle achieves a 4:1 velocity transformation between driving diaphragm and driven air, i. e. the air moves in and out four times faster than the folds itself are moving. This superior "motor" is responsible for the enormous clarity and transient reproduction that is to be heard from the ART drive units.