I have 4 matching Advent 6 1/2 drivers that I pulled from a Pair of Baby Advent II's and a pair of 1002's. They are close enough to identical for my needs and in great shape other than needing surrounds. I am thinking of using them in various designs but can't seem to find the specs anywhere. Searches on these speakers find several pages of foam kits and modifications but no luck with woofer specs. Any clues?