Subwoofers - Grille off or on?

Yes, no grills when listening. I know, WAF is at play, so put them on when not playing them. If you have cats, it is another story.

Stanwal,

You seem to be overly defensive or are puffing yourself, because I didn't see a single post in the thread that questioned your experience in listening to speakers with or without grills. The complaint about the use of the term always referred to the premise of OP's opening question.

You seem the one with the need to chill.

db

If its operating as a true subwoofer below 50hz or so then you shouldn't hear any difference on or off. Unless it vibrating on baffle.

Some loudspeakers are designed to be used with grilles in place some without.