I've got to say, I got these because they were closed and to be used in hobby-level recordings. They really do their job well.
The sound in these is quite good. Closed headphones tend to make me perceive the sound as a bit claustrophobic after extended usage. With these headphones I experience nothing unexpected in that regard.
These are labeled studio headphones and I have to say, the sound is a bit flatter in these headphones than in their siblings in the series, the semi-open Superlux HD-681 EVO. However, there's something about the highs that sounds a tad stale, listening to these.
Mids are great and the bass is okay.
They also come with a brilliant cable solution. The left can is equipped with a 3,5mm male stereo connector that you attach your headphone cable to. You'll never have to worry about ripping the cord with these. It also comes with two cables. One which I find a tad too short, the other a bit too long, but that's going to depend on how you have your gear set up anyway - but those cables are really bad. They're stiff and feel very cheap, so you're going to want to complete these with a nice braided cable fairly soon.
Regarding wearing these, they aren't very comfortable on your head after wearing them an hour or two. Granted they are closed cans and should kind of clamp to your head. The stock faux leather pads they come with gets warm and are perhaps a little too stiff. They're probably a lot more comfortable paired with the fabric pads that came included in the package, but strapping those on is a bit counterproductive, granted you buy these cause you want a pair of closed headphones.
The build quality feels okay with these. They are indeed a bit on the plastic side of things, but doesn't rattle or feel especially cheap compared to the HD-681 EVO's and that's probably because they are less flexible in nature, being a pair of closed headphones.
To sum it up I guess it boils down to what you're looking for. If that's a pair of closed headphones with amazing sound for the buck then these are pretty much your go-to cans. They are far from as fun to listen to as the Bass-Boomy HD-681 EVO's, but they feel more accurate when presenting the sound. I feel like all of my complaints gets canceled out by the lucrative price tag on these, and for that, I'm very happy with them.
If you're interested, check out my review on the Superlux HD-681 EVO's too. Just wrote that one.
Cheers!