Wayne Parham Messages: 18756 Registered: January 2001
Illuminati (33rd Degree)
Excessive moisture and direct sunlight are the two biggest problems for speakers, except of course over-driving them in some way. As long as you don't push 'em too hard they'll last decades provided you take care of them.
Also, don't store them in a position where the cone faces up or down. The cones can sag after several years, especially subwoofers.