Myself, I would keep the settings the same and experiment with 60 Hz and 80 Hz crossovers. From around 80-120 Hz and below, bass is non-directional, so to me you are getting the most out of your speakers (and I am from mine, which are around the same size as yours and are +-3 db at 48 db) since they won't strain, and the sub can easily handle bass up to 80 Hz without breaking a sweat.

It all comes down to personal taste, I just think that the current settings with the 40 Hz crossover was just leaving too large a hole there in the bass, and worry that doing Large+LFE will wind up with too much bass. If everything is calibrated right, it should be nice and smooth.