Do drivers become dirty when grilles are left on? Mine are difficult to remove/replace, and some take offense when guts are exposed. Same ones who think cookware should be hidden away as though one had an invisible chef or only dined out.
Drivers and how to clean them: Notes from ScanSpeak
Please use good judgement but if you ever wondered what the actual manufacturers recommend for cleaning your speaker drivers here's one maker's view:
https://www.scan-speak.dk/technical/tech-notes/
https://www.scan-speak.dk/technical/tech-notes/