I have speakers and subs that are well over 20 years and they are fine. On the other hand, I also have speakers that are less that 20 years old that are not fine. The only pattern I can think of is that I didnt uses the bad speakers for years and the foam/rubber rotted and deteriorated. So, my theory is that is you use speakers constantly they will last, if you dont they wont last. makes no sense but this has been my experience. My JBL sub ha been rock solid for over 15 years and gets very little use but the speakers have a solid rubber surrounds and the speaker is also coated in rubber. My 20+ year old tonnoys that I didnt use for 8-10 years literally shredded and collapsed last year when i took them out of storage and tried them.