I`ll copy you the Tannoy tech spec sheet I have for the SGM12x later - same driver/xover . I think they went from about 1987-90/91 after the LRMs. Driver are 3149`s , I think about £7-800 each at the time. 46 litre cabs, bass from 55hz ( -3 db)
I have just built some 100 L cabs - see Tannoy yahoo groups photo page . Mine are along the lines of the Balmoral ( try google ) and are sounding better than they ever have before . I`ve had them in LGM cabs and 12X cabs before but always craved a little more bass.
If I`d had the space I`d have built Edinburgh clones - 200L with slotted ports and bass to 30hz. One day.