Just realized that every single type of speaker tweeter design I am aware of has already been adopted in headphone design [even AMT (e.g. Obravo, ESS) and ribbon (e.g. RAAL)] - except for compression driver and plasma tweeter. Utilizing compression driver technology in headphone seems nonsense...

Saw a new old stock pair going for around 65 pounds. Tempted to buy it - I've been curious about that "S-Logic" voodoo since long time ago. Buying that pair also seems to be the least costly way to own a "S-Logic" equipped pair of cans. My hesitation upon pulling the trigger comes from the form...