Astell&Kern Layla Special Edition by JH Audio 12 Driver in-Ear Monitor (IEM) with 3.5mm Stereo Extension Cable with iBasso D-Zero Mk2 Portable Headphone Amp

Great sound, amazing engineering and design - highly recommended!

Excellent sound stage. Smooth but strong bass. I am using this with AK380 and AK380 Amp. It works better with the Amp and player combination than the player alone, which I found no difference when I use other high end headphone (e.g. Sennheiser IE800). Well designed and excellent, though the price is really scary. If you can afford the price, this is the one to hunt for. It will be difficult to find a IEM that can beat this set.