SYTaudio びーえー
Balanced Armature
http://sytaudio.com/wpcp/
http://sytaudio.com/images/syt-armatures.jpg
http://www.hearonic.com/en/index.aspx
http://img.diytrade.com/smimg/2249972/42726177-3828177-0/hearing_aid_speaker/5f39.jpg
http://img.diytrade.com/smimg/2249972/42664620-3726177-0/Balanced_armature_receiver/3cc4.jpg
http://cymbacavum.com/2015/01/30/the-biz-what-companies-make-balanced-armature-speakers/