It seems to me that you're running the Ref 3As full range without a sub. Before you go adding filters and subs, have you experimented with moving the speakers around in the room to see if you can smooth out the tonal balance that way?
Limiting a full range driver
My speakers, Reference 3A NEFES, have 2 full range 8" drivers. My question; is it better to limit the frequencies to 100 Hz and higher. My thinking is that the lower, sub 100 Hz signals interfere with the midrange too much with their larger cone movements. Or, is there no benefit to cutting out these frequencies?