[dwatanabe]

I've used akg k701, k550, ultrasone hfi580, sony mdr 7506 and grado sr225(can't use to record if instrument needs to be micd like an acoustic guitar) to record and mix music and I have to say that the one that makes the mix sound the best is always the 7506 despite the price disparity with most others. These not only have flat frequency response which makes you have as good an idea as you are gonna get with headphones of where your mix stands and they also, if you compensate for the midrange hump(which would make your acoustic guitars and vocals really come forward if you are using these while tracking), and  high rolloff while mixing you will have a good, consistent mix that won't shock you when you listen to it through some other set-up. There's a reason professional sound engineers keep these around despite there being technically superior headphones much like they use the yamaha ns10 monitors or shure sm7 microphones. All of these pieces of equipment have characteristics that are beneficial in sound engineering and at the end provide the best possible mix that will sound the best across the largest range of set-ups.

 

[punks15]

K550 will serve your friend well