have brand new Blue Microphones "Ella" planar magnetic headphones in a sealed box that I ended up not using. As a big fan of planar magnetic headphones, I've tried a few but ultimately stuck with my Audeze Sine for convenience of using the Cipher cable with an iphone. Having tried another pair of Ella before getting these, they have a much smoother, warmer sound than the Sine and significantly more bass. They too have a built-in amp for use with mobile devices and for greater bass boost, if desired. Can be used in passive mode with an external amp or with built-in amp in active mode (rechargeable battery).