Ultrasone announced their HFI-15G headphones today, which are super portable and actually the smallest headphones in the Ultrasone HFI line thus far. But don't mistake a small form factor for a lack of features.
In fact, the HFI-15G headphones feature the S-Logic Natural Sound Technology, which is patented by Ultrasone and acts to limit sound pressure by 40% on your eardrum and creates a more natural surrounded sound. This makes for a much safer and enjoyable music experience.
It also sports a decentralized driver position, which means it points the audio at your outer ear, rather than your inner ear. Other specs include a frequency range of 20-20kHz, an impedance of 32 Ohm and a sound pressure level of 96 dB. You can get the Ultrasone HFI-15G headphones now for $109 at various retailers.