Never heard anything like it
I have owned the Beyerdynamic dt1990s, the Sendy Avias, and the Sennheiser 58x. After using The AAA 789 with all four, I can say that these make all of those sound almost like toys by comparison. The frequency response is perfect, and the separation, sound stage, and imaging are worlds ahead of the other headphones I mentioned. The 1990s are not compatible with a balanced cable, so they can't even come close to competing. Compared to the Aivas, the Elex has much more low end and a little less in the highs. More importantly though, the Elex sounds almost as though you are not even wearing headphones. Once you hear them, it becomes painfully obvious that the sound from every other pair of headphones is coming from a driver a centimeter away from your ear; they have rendered every other headphone I have pointless.
Would recommend to a friend.