Most of the magic from the KNS 8400 is retained in the KNS 6400 design. You get a rock solid set of headphones with a pleasing neutral sound signature. Some of the design changes hamper the performance somewhat, but even so they are still remarkably good value being priced at a mere $100. Despite being only two-thirds of the price of the KNS 8400 they are still extremely well built and well sounding. The mechanical design is identical which means that if you are looking for a set of beater headphones for use on the move these are probably the best value in the KRK Systems headphone line-up. For a serious gamer these come very close to the KNS 8400 on all accounts except for their noise attenuation properties.