A 1977 Heresy should have a woofer made by Eminence with a coated, pleated paper "accordion" surround, though, not rubber.
Again, though, they should last forever if not damaged by abuse (e.g., a pencil or finger).
True.
I have 84s, which are identical other than having 3 caps on the crossover instead of 2. Well, that and after 20 years of mixed AV and music use I recapped them and replaced all the drivers and flush mounted the mid-horn and stuffed them with poly, but still.
I think you are more likely to need the ferrofluid replaced in the horn drivers, but even with mine before I replaced everything, they were just a tiny bit distorted. Very noticeable, since I changed the drivers one at a time over a year, but not a huge difference.
The main issue I have with them is the tweeter in the originals rolled off pretty early for my tastes. But new tweeters from Crites gave me full range.
Do you run them up and level? I really liked them that way versus on the floor. They have a VERY narrow vertical sweet spot that way, but pretty darned good for music and movies.
I don't listen to mine very often now, but I still love them when I do. After 30 minutes to acclimate to the sound at least. There's a reason they sold unchanged from 1950s to the mid 80s, and are still popular today in upgraded form. They work 1/3 of the way in the room, in corners, on the floor, in asymmetrical set ups... they work well pretty much any which way. But when they are right, they are far better than many might think. They are just finicky to get just right. Particularly on the floor tilted up.
Enjoy!
(for their "legacy" products and modifications) at audiokarma.org
