This is a rare bird indeed. A 1965 Jensen Professional Series C12-NC. I've seen a few of these in smaller sizes, but not many twelves, and I don't know what their specific purpose would be. Syntox-6 is a ceramic magnet, and it's described as a super shallow coned speaker. It seems to be very high quality, and it sounds extremely clear at low volumes. But my knowledge is limited on this one, so I haven't pushed it to see what it can do. I had the guys at Dixie Speaker check it out, and they just re-doped it and said it was otherwise fine.