I found some interesting comments over at Audio Circle:
Concerning the effects of these devices:
”Installing the SW1 on top of one of the speakers and switching it on changed the spatial representation of these recordings. 2-d became much more 3-d, with clean open space between all the instruments, and more depth contrast where there was little before. Tonality, harmonics, dynamics, etc. seemed unchanged...the illusion of performers in space rather than inhabiting a more 2-d canvas is enhanced in an enjoyable way... I’ve been listening carefully for any changes in tonality. The only things I can note are that the bottom end seems to have slightly less weight and body, but with enhanced dimensionality.”
Concerning the effects of these devices:
”Installing the SW1 on top of one of the speakers and switching it on changed the spatial representation of these recordings. 2-d became much more 3-d, with clean open space between all the instruments, and more depth contrast where there was little before. Tonality, harmonics, dynamics, etc. seemed unchanged...the illusion of performers in space rather than inhabiting a more 2-d canvas is enhanced in an enjoyable way... I’ve been listening carefully for any changes in tonality. The only things I can note are that the bottom end seems to have slightly less weight and body, but with enhanced dimensionality.”
Concerning a potential mechanism of action:
“So- these seem to work as many (but certainly not all!) users have described, and the mechanism is totally unknown. My own speculation is that the EM energy is somehow acting as a dithering signal in our personal aural processing chain (nerves and brain?), but this is pure speculation.”