Those numbers can't do not hold under an exact comparison, and, for comparative purposes, they should be considered 'ball park figures' at best. A couple other subs to consider in this range is the Hsu VTF-1 mk3 and the Premiere Acoustics PA-150. The VTF-1 mk3 splits the difference in deep bass output between the Monoprice 10 and Speedwoofer 10, but has a bit more mid bass punch than either. It also splits the difference on cost. The PA-150 can almost match the deep bass performance of the VTF-1 mk3, but has pretty monster mid bass output for the price, $500.