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.
She loves me she loves me not!
So - as in the saying above when de-pedaling a daisy...
Speaker grills on speaker grills off.
The reasoning for my question if I keep them off inevitably I will damage them moving them around when in the garage- -forget where I put them - and bitch cause they take up space.
Thank you for the education.