The ultra tweeter and the magic ring do not fit the description of any conventional pieces that I have ever read or heard about. But, let me think, the Magic Ring's function seems to be very similar to the TDK rings that went on cables, to reduce RF and other similar things. Have them, and did not hear much of an improvement per se.
The theory behind the Ultra Tweeter, might be credible especially when people had run experiments with ultra tweeters, that go beyond the human hearing range of 20K....Some of them being Infinity Emit and Super Emit tweeters whose range went up to 40K, or was it 45K... Someone ran a test and eventhough it was implausible for anyone ever to be able to hear the difference between regular tweeters and super ones, someone came out with a reasoning saying that the extra Ks in response gave the listening the perception of more naturalness in the highs, almost like sonic headroom. I sort of believed this, but then, I am also an owner of the Infinity Kappa 9s.
In paper, there are things that do not make any common sense, but in practicality, they seem to have an audioble effect. It is due to this that some people stick with radio shack lamp cord speaker cables and cheap interconnects and then, others spend as much as a car on a single run of cables.
I think the manufacturer of these Ultra tweeters are doing so because there is a market out there. $400 is not shall I say cheap, but nor is it prohibitibly expensive to catch of jaded audiophiles quest for the ilusional potential audio nirvana.
Having not "heard" these tweeters can only speculate. I do believe there is a high percentage of what we call :"built and they come" or in this case, "market them and they will fall for it."
Anyone interesting in laying out $400 for a pair of these and "hear" how they work?
Got another idea, maybe they allow my dog to listen to artifact in the recording that cannot be played with conventional tweeters.
Paul