in all cases described the apertures 12 24 are wide enough that the movable portions of the diaphragm defined thereby overlie several rows of panel holes 3 this is unlike the aforesaid high patent at fig7 of that patent where each movable portion of the diaphragm overlies only one row of panel holes fig4 shows an alternate preferred embodiment of a stator panel 26 with different amounts of curvature in two directions as would be used to construct a similar esl panel as fig1 and 2 a horizontal dispersion 28 of about forty five degrees and a vertical dispersion 30 of about thirty degrees are ideal angles to disperse sound to a listener who is either reclining on a sofa or otherwise standing and located at a distance of two meters or greater if such a panel were twice as tall as it was wide then the radius of curvature in the horizontal direction 32 would be about one third that of the radius of curvature vertical direction 34 fig5 a is a cut away section of a coated metal perforated panel 36 as would be used in a typical prior art commercial esl panel assembly the difficulties associated with the insulation of punched perforated sheet materials are well known in the esl industry and are also discussed in detail in the bloodworth patent a typical stator panel has about 5 000 hole edges per square foot on one side alone it takes but one.