well one of my polkmomo subs kicked the bucket today. It started making a loud popping noise when I would turn it up. So I took it out and examined it and found out why it's making the popping noise.
The cone that attaches to the spider has come apart almost 3/4 of the way around it. Thats the first time I have had a sub to do that. The speaker is not blown though. The voice coils are still reading 4 ohms on my meter.
Im going to ship it out for repair on monday. It made one year but not three years. But if you can play your subs loud for a year without any problems your doing pretty good.