There is something great going on with the cloth/paper bass drivers. A friend of mine had concert speakers, i guess from 80's that had 15'' cloth bass driver. Epic slamm, sharp and powerful. Somehow modern composite elements don't do that so well.

Yea, I like the use of cloth. Last speakers I had with cloth drivers was the pioneer cs77a I believe it was. They were very pretty to look at but sound was decent due to midrange sounding bit hollow. The 12" cloth woofers was amazing though cause punchy they were and had good quick slam. The pioneers used cloth surrounds too but I think it limited it's excursion while the technics 13" woofer is cloth with what seems to be rubber surrounds for higher excursion but never tested it's limits yet but can say I don't need my subwoofer no more since the woofers in the technics seem to extend as low but sounds lot more clear and clean.

Your friend probably used some form of altec lansings maybe. Atlec lansing made a lot of huge heavy speakers.  Altec lansing was known for their speakers during the 70's and 80's.