Found a driver with 1/3 the qts figuring 1/3 the size. A 12" hd shielded on special for $69. One good driver instead of 2 cheapies. fs 28 vas 3.99 qms 11.07 qes .33 qts .32 xmax 7.5mm Boxplot says 1.94 cu ft 22X9.6X15.5. with a 3X6 vent. That seems a reasonable size and the plot looks like flat from 25Hz up but I don't understand the 3 colored waves. Opinions?