Sound reinforcement and intelligibility in acoustically challenging venues.

In some places, like churches that have very long reverberation times, voices and musical instruments can lose very quickly their definition. Sound reinforcement may be necessary. But when it is done with large speakers on both sides of the sound stage it can cause the acoustics to get louder and blur even more the sound because of a lack of spatial coherence.
In this case can WFS be the solution?

Natural sound propagation spreads outwards from a source, the same way waves on the surface of a pond where you threw a stone.
The so-called « stereo » sound system usually places a couple of speakers on the sides of a sound stage. You can hear a real stereo effect when you stand in the line right in the middle of the speakers. But as soon as you step to one side or the other you lose can only hear one speaker and you lose completely the spatial coherence between the acoustic sound and the amplified sound.
We could summarise that natural sound propagation is divergent (goes outward) where as so-called « stereo » amplification is convergent (ie, goes inward).
More over speakers placed close to the walls can increase the amount of sound reflections in the hall.

Chapelle des Cordeliers, Toulouse, France

With WFS the speakers are placed in front of the sources and from side to side.
It’s more invasive visually for sure, but for the quality of the sound diffusion and comprehension they’re just no comparison.
The smaller speakers spread across in this way don’t trigger so much the live acoustics of the venue. And since the sound spreads in the same manner as natural sound disperses our ears can isolate a voice or musical instruments in the middle of the reverberation of the hall.