I've been very impressed with these things. I've been using HD25s and ultrasone Pro750s for years now, and had these for about a year. I havent stopped using the others, but these are now the headphones I reach for first in all but one circumstance.
Accuracy of sound. Pretty much the whole spectrum is there and no part of it struggles to be heard through these. They go very low, very high and are balanced in between. Very fast response, tight and detailed. I do actually use them for starter-for-ten rough mixing as I go, or even while mixing-proper in conjunction with my monitors. That might not sound like a big deal, but it is in fact HUGE for me. I've tried many times to mix with headphones and failed consistently. You lose track of levels, both of instruments and relative levels of different parts of the spectrum, way too easily, and with just the shear physics of getting low frequencies out of little drivers its really hard to get detail out of the low end. These have those problems, but much lesser extent than I've become accustomed to hearing in headphones, and so I do do some mixing with them.
The forgiveness/forgivingness of the sound is in the midrange. They can and will let some ugliness in your mixes slide past unnoticed in the mids and low end of the high mids. But for me to even get to that point in a desription of headphones is unheard of; I'm talking about mixing on headphones, here. That, for me is, one more time, HUGE. I've used headphones to place mics, I've used headphones to do the bulk of dialing in of guitar tones in isolation, to be fine tuned later after a check through proper monitors, I've used headphones as references and made itty bitty tweaks on them, I've but I've never sat and mixed with them for hours *with success*. I've tried, but its never sounded right. This is new to me. I'd learned to mistrust headphones for that. I like it a lot. Its like having extra monitors that arent affected by my room (I use Adam A7s and a sub 8, and fwiw the overall balance and character of the sound of the HD25s is similar to those (with differences that I wont go into, since this isnt a review of adams, suffice to say while the balance and character are similar, Adams > Headphones, in lots of ways, and Any Good Monitors in a reasonalbly well treated room >>> headphones, generally))
If youre shopping for nice sounds, the reason I dont trust them *all that much* should be added to your reasons to buy them if youre just looking for good sounding headphones. They are very good sounding headphones, and hit well above their price in sound quality. I would have NO compunction whatsoever about getting them for pure listening pleasure.
Spatial representation in terms of apparent depth of the source is decent. Not much more than decent. I've heard better. I've heard much worse. Stereo represetation; they're headphones! You can pick out left, right and if you can hear a trace of a signal in both ears then its somewhere in between and might seem to be coming from some indisctict point inside your head, but mainly things seem to be left, right, or smack in the middle of your head. i.e. they're binaural. Want a good stereo field? Use speakers, set up a good listening position.
The market that these headphones should really shine for - neophyte would-be audio engineers, people just starting out making their own music in their houses for the hell of it. You can (and should) get some decent monitors. Thats a given. But for you to be able to effectively use those monitors you need at least a reasonably well treated room. The cost and logistic difficulties are mounting! As are the required knowledge and research. You should do that in the end, if youre serious about making music, BUT, With these you have something you can make decent mixes with in between now and then, and frankly, I'd rather mix on these than low-ish end monitors in an untreated room. As a stopgap between 'nothing worth mixing on available' and 'decent monitors in a decent room' these are a relatively inexpensive, relatively reliable way of scrutinising your mixes that you likely wont outgrow even when you do get a good monitor setup and well treated room.
The isolation is also good. Not amazing; they let a little more through than HD25s, but it not much different. The design also seems sturdy and utilitarian enough that they can take a working environment. If someone dropped them or sat on them or something, my heart wouldnt leap into my mouth. Actually, come to think of it they've been dropped quite a few times and there were no cardiac gymnastics, or any damage to the phones. They havent recieved anything resembling 'abuse' however, but like I say; they seem pretty tough, I dont bother babying them.
So, the checklist of ATH-M50 awesomeness
- Great sound, accurate enough to do some pretty passable mixing on CHECK (perfect for people new to mixing that havent got a good space for it set up yet)
- The only headphones I've ever used that I'm prepared to say that of? CHECK.
- Good isolation? CHECK.
- Very comfortable? CHECK.
- Light and durable? CHECK, and I havent how shall we say, 'tested' the M50s durability, but they seem pretty solid.
- Excellent value for money? CHECK
- Doubly so if you arent doing any mixing? CHECK
The detraction: a little forgiving, but the detail audiable with them and the fact that its *mostly* unflattering reproduction counters it, imo.
Oh, and the one circumstance I dont use them as first choice is tracking anything loud when in the room with that thing, after sounds have been dialed in, mics placed, etc. HD25 isolation might not be that much better, but it is better, so I track with those for the loudest sounds in the room. Below a certain point, though, they're fine and you shouldnt worry about the isolation if youre trying to decide between these and other isolating headphones; they do isolate very well, its just in some circumstances I want to shave a couple of dB off the level through my phones (I like having hearing) and get a small degree of benefit from a little bit better isolation, so I use that instead.