OMG, just removed my speaker grills and the sound just opened up to a new level!

My recently purchased Focal Maestro Utopia speakers look so good with their black front baffle and side and back Camara white, I couldn’t even think about removing the grills to hear what they sound like with them off. With nobody around to voice their displeasure to seeing those drivers I boldly went were no man, or in this case myself, said he would never go and removed the grills. Hello, said the speakers
this is what I really sound like. I might not be as pretty, but love me for what really counts, how I sound,
not how I look. I have to say I love them even more and they’re not looking too bad either! 
Congratulations on your daring move! ;)

Yes, this is basic, one of the simplest and effective ways to improve speaker performance. I remove absolutely every speaker grill possible. Consider a speaker playing through a grill to be akin to firing a tomato at a strainer - it's a mess. Not much good comes from shoving a mesh/grill in front of drivers, despite the hoopla over Paradigm's grills on their new line. Sure, it has a more diffuse sound - because they're blocking half of it!  :(

Magnepans - all panels with fixed grills - suffer significant degradation of sound quality, too. I have the Kingsound King III electrostatic speakers, and the difference between grills on/off is striking, quite evident. 

I'm not as  impressed by speaker companies that put fixed grills on drivers. Wretched mistake, imo. At this point I don't know that I would own such a speaker (Aside from perhaps HT use, like the small, wall Maggies I use because they are inexpensive and get the job done).  :) 

There is one thing that can be beneficial about a grill; it can help tame a wickedly strident tweeter. 

Have your wife blindfold you , and see if you can really hear a difference. Do it 20 times , see how many times you get it right .
Amazing how after decades in audio still there are new discoveries to be made.
I didn’t think focal made removable grills over their tweeters? That the grills effect the sound of the lower fq’s makes me think they would be good sweater fabric.