Yup, their build quality is great. They don't look premium, but the fit and finish is really nice, and they look like art pieces. I like how flat they sound. It's just a really clean presentation. If I play them louder than usual, the music doesn't make a lot of noise or bothers my ears. They sound unique. I can't compare them to anything else I've heard. They remind me of good paper cone speakers. With no apparent flaws, and nothing sticking out, I consider them boring. One would think that basically perfect-sounding headphones would be exciting, but no, it's just not engaging at all.
When I wear them, sound doesn't seem to come from the headphones into my ears. I just perceive the sound image as a whole, almost visual. When sounds pan, my eyes automatically track them. I'm not sure if the slightly forward-facing ear cups not having a pivot to make them lay flat on the ears are responsible for that. It's distracting, because I use my eyes too much when I can almost see the sounds in front of me and to the sides, almost like invisible speakers.
Tonality-wise, nothing about them is harsh or muddy or shouty. They're clear-sounding, with a dry signature, and the dynamics are fast. Maybe that's also why they sound boring to me. Nothing sustains. Everything is just right, even if the bass is not ear-filling or thumping. But honestly, these are really bass shy. People call the beyerdynamic DT 880 light on the lows, but I have those, and they are bass canons compared to the SRH1840.
One thing about them is that the nuanced sounds are just like that, nuances. They're there but don't stick out like in other headphones. But when it comes to revealing sound character itself, they do that in spades. So, I'd say they're more suited for analytical purposes, not for music enjoyment. They are not engaging in my experience, even if they're not lifeless like other analytical, reference monitors. There is nothing sterile about them, but also, musicality is not their strength. There is a layer of something missing from them, which is what makes them so revealing. I do admit I tend to enjoy them with my iPhone 8 Plus through the dangly dongle. They sound a bit screechy and distant, but that seems to work with them.