Loudspeakers are delicate devices and it is important to care for them properly to maximise their life and maintain their sound quality.
Here are some tips on cleaning and caring for speakers:

Speakers should not be exposed to direct sunlight as sunlight can fade / discolour the finish.

Only a soft cotton cloth should be used for cleaning. Microfibre cloths can leave micro-scratches in the high-gloss lacquer. Solvents in strong cleaners can attack the surfaces.

Dust should be removed from woofers and mid-range speakers with a soft brush at the most. However, small amounts of dust have no effect on the function.