On the mad board there was a thread on this question.

Say we have a 16 4" driver sealed box array. 10" wide ~7' high. 4' from the wall. The listener is 9' from the driver. A std home setup.

Is a baffle step correction circuit required.
Is the edge diffraction not a factor.

- I would think the bsc is not as needed since the driver sees 1/2 space above and below.
The edge diffraction may be worse since it is a line source and has an extended nearfield.

-Linc