The AH-D7100's immediately became my go-to headphones for daily use since the day I purchased them three weeks ago.  They sound much  fuller compared to my Beyerdynamic T5P's and produce high sound levels with unamplified portable music devices.  They produce deep, rich, better-defined bass compared to my Ultrasone Pro 900's..      Sound is uniformly clear and well defined across the audible spectrum.  Given their high efficiency, transient responses and punch are state of the art with  unamplified devices....the sound is powerful, an adjective...