Wesseixas this is as simple example as I can find http://www.bio-sound.com/images/Wave2D1Src.gif note the molecules are not going anywhere just the wave, all transducers do this. And if you looked into it I offer fullrange, ribbon and horn based systems. I have no bias to any 1 design. Such as many posting here do I try design most every type of loudspeaker. Does bother me to see so many wrong comments about performance of various transducers or loudspeaker types etc from the uninformed. You should read all the - about ribbon designs passed about much of it wrong but taken as fact now. Same with horns.