Difusers on the speakers?

I’ve read hundreds of posts on this forum about room treatments,

Today the following occured to me

• Many posts talks about room treaments - specifially diffusers - and how their placement benefits sound quality by dispersing/absorbing reflected sound waves
  • my speakers are a rectangular box 10" wide and 40" tall with a very flat front
  • it occured to me that having some type of diffuser (or absorbtion material) on the front of them might improve sound quality

My guess is that speakers with a slightly curved front has a buit in diffuser

Has anyone tried this?

What was the result?

Cheers - Steve