How 'bout some JBL 2241's? They'll do pretty well in a 10ft3 box. Best if tuned to 30Hz or 35Hz but 42Hz isn't too bad.If tuned to 35Hz, it will be flat down to f3 of 35Hz and f10 of 28Hz. If no cabinet changes are made, the existing 42Hz tuning will give a small 2dB rise at 50Hz.