WmAx, you mentioned in your above post: "Those ED drivers have high power handling and high excursion, but they have poor motor linearity (high distortion)". I assume that you are referring to what ED calls: "Total Driver Linear Displacement" which they list under the A7s - 650 Subwoofer as having 6394.000cm³. I noticed on their A5s-300 Subwoofer, that they list the "Total Driver Linear Displacement" is 1384.3cm³. Both of these subwoofer models are described by Ed as being very low distortion. For those of us who are not as knowledgeable yet with how motor linearity works, could you please explain these specs and specifically what would a buyer look for with these numbers? A higher number or probably a lower one? At what number would be considered borderline acceptable or unacceptable? Also, why are most sealed subs front firing? Wouldn't down firing be easier to place in a room? Thanks in advance.