Thanks Martin. That's more than I know about USS; I wonder if they're similar to AR domes. And yes, they do sound great. One of mine went bad. The Vifa D27TG-35-06 1" Silk Dome Tweeter from either Madisound or Part Express sounds very similary to this unit and the SEAS just as an F.Y.I.
Also, we use two rear A25XL (with the Vifa, which is better than the origninal domes that rang and blew up) for our 5.4 surround sound home theater: two A10s for the center, with original units, left and right are the A25 with USS drivers except the right now has the Vifa tweeter. In the rears each A25XL has a Sunfire True Subwoofer Junior beneath it (they're mounted on stands) and they add great output from 40HZ down to at least 30.
Modified VMPS smaller subwoofer in center, Sunfire Tru Subwoofer Mark II to the left in the front. I guess SVS get deep bass below 20HZ but that would be too much for our room size.
Thank you again.