German headphone manufacturer Ultrasone AG announced PRO 900 headphone with S-Logic Plus technology. The new S-Logic technology reduces sound pressure on the listener’s eardrums, while improving the sound impression. PRO 900 are closed-back headphones with a new 40mm titanium-plated driver and a new soft USC-Cable that is paired with Neutrik connectors.  The headphones have a frequency range of 6-42K Hz and Impedance of 40 Ohm. The Ultrasone headphones contain MU-Metal shielding that reduces the amount of radiation directed to the listener by up to 98%, as compared to conventional headphones. How much radiation does a headphone give out? Anyway, the PRO 900 is available now from Ultrasone’s network of dealers for $599.