She loves me she loves me not!

some speakers, like Avalon, are designed to listen with grills on, others it's up to you...I always put grills back on at end of day...(except for my Avalons...)..

Joy of Vinyl YouTube channel just had a vid on this earlier in the week. From my experience, I can't tell any sonic difference; to me, it's a matter of aesthetics....

@larsman, aesthetics are truly subjective. I like views of speaker drivers exposed especially if it's kevlar. 

@czarivey - are Kevlar the white-looking cones? I like those too; my Marten speakers have those, and they don't even make a grille for them.... 

Every speaker is different. The Spendors that I've owned were better with grills on, but almost all others I've had were better with grills off. Store them in your closet if not being uses. The garage is no place for them.