Open baffle speakers have many virtues, very deep bass is NOT one of them because the front and back waves of the drivers are out of phase and bass frequencies wrap around the speaker and cancel each other. One could use subwoofers or box woofers for the lower frequencies, but, depending on your taste and priorities, the bass without such augmentation can be good enough. I've heard PureAudio Project open baffle speakers that, for my taste, have enough bass without augmentation. The "small" version has twin 15" woofers, and the taller version has four 15" woofers. I consider this brand's speakers to be among the very best for the money.
I've heard some other open baffle speakers with quite large baffles and some with sides that go backwards to effectively extend the path length for front-back interaction, but these tricks only reduce cancellation.
