Closed Back: Great for practicing anytime anywhere, no sound leaking but some find fatiguing for prolonged use, tend o be bass heavy also less sound stage. examples: Sennheiser HD-25, Sony MDR-7609, Beyerdynamic DT770, Audiotechnica ATH-M50x. Open Back: Better sound stage more neutral frequency response, not so good in isolation or sound leak, less fatigue on ears. Examples: Beyerdynamic DT880 (Half/open), DT990, Sennheiser HD589, HD600, HD650. My experience i own 3 headphones and 1 iem (Sennheiser HD-25, Senn HD 6xx, Sony MDR 7609, TFX Galaxy 2) and i love them all, but i tend to always use the Sennheiser HD-25 I've also tried the Audiotechnica ATH-M50x and the Beyerdynamic DT770/990 and they were not to my liking.