I use these for testing tracks... The HD 600 have a blue label, while the HD 650 have a silver label. The color of the side pieces are black on the HD 600 and grey/silver on the HD 650. The video is black and white, so it's hard to tell. To me it looks like the label on Flume's headphones is more likely silver than blue. So that would be the HD 650 and not the HD 600. Hard to tell. Soundwise the HD 600 have allegedly a more linear frequency response and the HD 650 more bass and wider stereo panorama.more
Every little detail can be heard with these headphones. The HD650s are great for analyzing songs and for making great mixes. These headphones are a critical tool to have in your arsenal along with a set of good studio monitors. Be aware that they are open headphones so everyone will be able to hear what you are mixing!
These headphones are one of the best things I have purchased. These are a little flattering in some areas but don't over due it. Just enough for you to be able to listen for an extended time. Very comfortable and light. Very extended frequency range and allows me to hear sounds in tracks I have never picked up before. :)