One look at the specs tell the story HED-10DVC SPL: 88 dB Fs (Hz) : 24 Hz Qts : 0.669 Qms : 13.867 Qes : 0.703 Vas (l) : 75.41 l X-max : 12 mm HED-15DVC SPL: 90 dB Fs (Hz) : 20 Hz Qts : 0.607 Qms : 11.473 Qes : 0.641 Vas (l) : 332.64 l X-max : 17 mm If you simulate these drivers under WinISD for a sealed box, be ready for a surprise. The things are ruler FLAT. Amazingly so. I can't believe their response. True, their boxes are a bit on the big side, but the 10"'s curve can be excellent on a 80 liter box, and the 15" needs a 250 liter box. What do you think? If I build a sealed box with these drivers, will I really get that kindof performance? Seems too good to be true to me... More so if you consideer the drivers cost around $85 (for the 15"). Thanks!