I have had a pair of 7SE for about 4 years, wonderful speaker. The 7NT has a Nautilus-type tapered tweeter that reduces standing waves. The mid-range is basically the same and the mid-bass driver on the NT has the mushroom dustcap that makes the driver more rigid. The NT also has the flowport dimpled port. The NT has a more pronounced angle on top to accomodate the new tweeter design. There may be different crossovers, not sure.