Heres my long review of these from reddit:
***Go to #3 for the review lol-------------------- PICTURE
http://imgur.com/a/nSS0V
1 First off I want to say, this is the only personal review of these on the internet. A few blogs/ websites have reviews but they seem more as if theyre just marketing them rather than being really in depth. I felt this could help some people out.
2 So anyways, about a month ago I got the Beyerdynamic DT 990's. Even though I read they have an extreme high end i chose to go with them anyways. They are the most comfortable headphones ive ever put on my head. But the high end is absolutely ridiculous, I'm a drummer of 6 years and even my abused ears couldnt handle them. Which is a shame because I really wanted to like them, especially considering how comfy they were. So I started doing hours of research, and figured for the type of production I do ( dubstep/future garage/other random ****) the DT 770s would be a good option. One of my buddies went to NAMM and knows how much I love my Hs8's so he told me Yamaha had brand new Studio headphones out on display and to check them out. S0 i looked them up and found very little info about them, yet saw that guitar center near me had them in stock.
3 I go to guitar center to Compare the Yams to the 770's. The dude wouldnt take the Yams out of the box for me to try so I got annoyed and bought both to compare them. For hours I listened back and forth between the 770s and yams to all different genres. Surprisingly the Yams outdid the 770. The Bass on these is incredible, yet not overbearing. The way it seperates the lows/mids/highs from eachother is so helpful for mixing purposes and even listening. The high end is extremely detailed but not spiked up, no ear fatigue from these, although the 770s had maybe 5% better high end these are still great. The mids are extremely full and honest. I can hear every little detail/change i make while designing a sound, anything from Saw stacks, basses, atmospheric chords to plucks. No Change goes by unnoticed. The build quality on these is crazy for 170$, they have a very premium feel/finish except for the cloth covering the drivers, that id prefer they change and maybe make a little thicker. As far as negatives go, Id say the cloth on the inside that i just mentioned and the high ends could maybe be 5% tighter. But thats being really picky. Also the overall comfort was better on the 770s, while these arent really that bad they could be a bit more comfy. If you told me these were 300$ Id still buy them and think they were made without any compromises.
4 As far as comparing them to the dt 770s, what made the Yams really win out was the Low end and mids.Both were being clearer, more telling and just overall better. A few songs where the Yams really stood out was Virtual Riot- " stay for a while" and Skrillex "leaving". Both of these songs have a very deep low end and alot of random highs, the reverb tails and the low end was so much clearer on the yams. I love how the Yams Do everything they do while still being an overall pretty flat headphone, definitely flat enough for serious production.
5 So overall Lows- 9.5/10 Mids- 9.5/10 highs- 8.5/10 Comfort 7/10 OVERALL 9/10 * especially considering theyre only 170$