Sony recently released a firmware upgrade which changed the ZX1 sound from the original firmware sound. I first tried the disabling sound enhancements trick on the original firmware which resulted in the exact same sound improvement as doing the trick on the later released firmware which started with a different sound. Meaning that Sony by default is applying some sort of internal EQ to the sound via the sound enhancements app in each firmware (even if you have EQ off) and you can only turn off the internal EQ by disabling the sound enhancements app.
This leaves you with the pure sound of Sony's dap, and it is much much better to my ears than the sound Sony is forcing the ZX1 to produce by their own EQ! The dynamic range increases big time, natural timbre and decay is much better through entire frequency range, high extension and air is much better, soundstage much more open, bass has better extension and texture is incredible, mids become closer in a good way while voices are more real. Its just better in every conceivable way to my ears. It sounds way less digital and much more natural.
It honestly amazes me that Sony are crippling their own dap by default with unnecessary sound processing.
Edited by T.R.A.N.C.E. - 5/6/14 at 5:24am