Wayne Parham Messages: 18835 Registered: January 2001
Illuminati (33rd Degree)
Yes, that is typical and it is the result of room modes.
Read about multisubs and flanking subs. That's the way to get smooth bass which is uniform in all locations in the room.
In the meantime, you may be able to mitigate the straight-on dead-spot by reversing the wires on one of the speakers. Since there's a null right between the speakers, this may help in that one location. Doing this will sacrifice sound quality in other listening positions though.
Using multisubs is the answer to smooth bass throughout the room.