… this is the 1x15 which weighs a mere 70-lbs
Filled with helium, maybe!
I think mine weighed in at closer to 95. Because they don't handle a lot of power and have very low resale value I turned mine into a big experiment: I swapped the 8" mid driver out for a modern, Eminence 6" mid and the EV 15 for a Faital.
With tons of help from smart people here I was able to re-tune the box for the Faital and design a new crossover for the mid. The end result sounds very similar to the original format, handles more power and, at just over 60lbs, weighs 30lbs (!!!) less.
Was it worth it? Nah, probably not really. At 60# it's still pretty heavy and, even though it sounds very good, that new technology is still being limited by an ancient cabinet design. Sure was fun, though, and I do gig with it occasionally - and it sounds great.
If you really want a similar sound in a smaller, lighter package maybe talk to Don Oatman at Low Down Sound. He builds custom cabs, has done a lot of multi-driver designs and his cabinets are well made and sound good. His prices are pretty attractive, too.