The excellent iBasso IT03 earphone has great clarity in all of the frequency ranges.
Clean, extended, grainless treble with good vocal for female and extended subass.
This IEM has good isolation and a solid build quality. Really good value and awesome tonality.
Check out the earphonia.com iBasso IT03 review for an in depth review:
Pairing with the Astell and Kern AK300 digital audio player has an articulate wide character with good synergy.
They are both recommended and would complement any audiophiles collection