I have old Linn Sekrits with floor stands in a secondary system. They have those metal grilles, and I've never had a concern that somehow the grilles might be keeping the speakers from performing at their best.
It would be a strange design decision if they did. ...Although, I have Reference 3A DeCapos that came with grilles of fabric stretched over a thin MDF frame, and those frames did degrade the sound somewhat, so I've never used the grilles. Fine speakers but dumb design decision (which may have been corrected long ago).
But I have never suspected the Linn metal grille of harming the sound.
It would be a strange design decision if they did. ...Although, I have Reference 3A DeCapos that came with grilles of fabric stretched over a thin MDF frame, and those frames did degrade the sound somewhat, so I've never used the grilles. Fine speakers but dumb design decision (which may have been corrected long ago).
But I have never suspected the Linn metal grille of harming the sound.