It would all depend on what's available. Get enough volume displacement and a powerful amp and you can easily go beyond that number (with care).
About the narrow-band valleys, it never is a good idea to just blindly boost at such a frequency anomaly. If it is a valley, happening due to a reflection, all the energy in the world isn't going to solve it. Find out what does what, if one
does use boost, watch the distortion graphs + frequency curve to see if adding energy really
does level the frequency drop.
In more simple terms, one cannot EQ a null. If it happens at a low enough frequency, say below 80-100 Hz, maybe another driver can take the 'bump' in EQ while dropping the energy at that spot of the driver that suffered the dip. At such low frequencies it's
always a good idea to have more drivers carry the load. Say: 2 mains with low end performance (running full range) plus 2 subs. One can then use one where the other falls short. Maybe even keep the bass full stereo, as that does have
benefits beyond what's often assumed.