This page explains the cause of the orverlap and how to resolve it.

This is a situation where the sounds from multiple speakers are overlapping.​
When the sounds overlap, it becomes difficult to hear the content.

Cause

The cause of overlap is that the coverage areas of the two speakers (SP) are large and require additional coverage.

Solution

Arrange SPs so that their cover areas do not overlap as much as possible. Also, arrange the SPs so that there is no difference in angle between them as much as possible.

This seems simple, but it is easy to overlap in the following cases.​

When SP faces. If the designer is too concerned about the sound pressure in the center becoming weaker, it is easy to make the SP cover areas overlap as shown on the right. It is better to clearly separate both cover areas as shown on the left.

Also, if SP is installed behind the audience seats in the stadium, there is a possibility of overlap.
The coverage areas for 1F and 2F should be separated as shown on the left.

However, overlap is not necessarily bad. As shown in the figure below, the overlap of the main SP cover area places the sound image in the middle. When overlapping SP coverage areas, be aware of whether the sound image needs to be placed in between and whether the distance from the audience is equal.