This is a strange question but can long term exposure to direct sunlight ruin your speakers?
I noticed recently that in the mornings, the sunlight creeps upto my speakers. So for around 3-4 hours, the speakers are in direct sunlight.
Second question - with the nice audio stands that you get these days, electronics are constantly exposed to dust. Is this bad? Should they be kept covered or is the best solution just to dust them from time to time?