I'm looking at a good deal on a 20 year old Peavy 410. How much longer do you think it might last at 1/2 it's power rating ? From what I read about speakers, cloth roll (what we usually get) surrounds last at least 30 years. But how about the cone, coil, and spider glue ? Home stereo woofers with foam surrounds are lucky to make it 10 years. I suppose it is cleaning solvent fumes that eat them up. A price to pay for getting full range at low volumes and power, loose foam surrounds move well at low volume. But pro speakers are said to last much longer. How much ?