I'm finding with ER4S and X5 the refinement and imaging is certainly exceptional. It's hard to explain exactly, but my other players cannot image as vividly as X5 does. Each instrument for example in the mid range forms a very detailed image, a much clearer image than I'm used to and remain considerably coherent individualizing themselves around one other. Makes life very easy listening to one sample. Plus they don't seem to drown each other out as a passage gets busy with many instruments, that tight refinement just holds it all together.
Edited by H20Fidelity - 2/26/14 at 2:19am
For what I'm used to coming from the Hisound players those units are touch bright and push their detail out differently, especially around the upper mid range which gives vocals a good amount of detail and grind. X5 on the other hands is much smoother but I dare say possibly above the Studio V detail levels, (though in a different manner). Because it's not as bright/cool you have a different concept. It's especially notable the lower mids sound full and thick in comparasion, they have this semi creamy sound to them.
I'm hearing little bits and pieces (samples) such as lips closing together and breathing in before the next song line. There's a deeper level of extension with some vocal tracks I know well. And the background is black black black.