I have a pair of Vantages and one started crackling a few days ago. I have tried lightly vacuuming it but it worked only briefly ( a minute or so) before crackling as before. I have read about using a soft paint brush, which I will do next. Should I try a more powerful vacuum? I used a household vac to avoid damaging the panels but I could use my shop vac if it would work without worry. Could this be caused by humidity, as the stereo is in a room that has doors that are sometimes open to the patio? Whatever the cause, what more can I do to stop the crackle, and prevent it from reoccurring?