My Stepfather gave me a set of the title referenced speakers that he used to build a set of spekers with in the 1960's fashioned after the Klipschhorn design. I used those speakers in the 70's and they absolutely blew away my friends name brand speakers of the day. I am thinking about using the 2 that he gave me to build a sub woofer but do not know, or can find out, a thing about the. They are original brand new speakers in the box that have been in storage for 30-40 years. The cones and and paper look great in one and I have not broken the factory tape on the second one. Any help is greatly appreciated, THANKS!