I've had these headphones for many years, I love them, they are the best ones I own hands down.
They do need an amp. Get a Fiio e10, which is an Amp/DAC (processes audio via USB for a pure, distortion-free signal)...
Help me pick between 2 laptops :)! I can get them both for $730.00
https://www.amazon.com/gp/aw/d/B015PYZ0J6/ref=mp_s_a_1_15?ie=UTF8&qid=1474438455&sr=8-15-spons&pi=AC_SX236_SY340_QL65&keywords=970m+laptop&psc=1
https://www.amazon.com/gp/aw/d/B015PYYDMQ/ref=psdcmw_565108_t1_B015PYZ0J6