I am using the TAD 703 Super High Tweeter, going to 32 kHZ. So far so good, the sound is fine. I never complained…we know the ear is included up to 45 kHZ, in ear frequencies up to 18-20.000, standard are 12 kHZ.
I don ´t know if you ever tried to improve the presence of your audio system by using a Super High Tweeter reaching up to 150 kHZ? If not I suggest you may test it. Medical doctors told us that the surface of the face, the skin, including the front- and paranasal sinuses, and the retina (pls. never use glasses when you listen to your system), are receiving parts of the sound you get. Also the midriff is a receiving part!