| Sealed designs are quite forgiving. DD probably recommended that size to maximize output of the drivers. You *can* go smaller, but you will lose a bit of raw output and low end.
Build to your plan (1 cube each) and stuff the box heavily. If using Polyfill, stuff it fairly tight; if using fibreglass go with R12 and line all sides and add two layers to the back panel. Stuffing can add up to 30% volume if done right.
Best,
Mark |