Transparent and beautiful sound with good sub-bass extension
Craftmanship is exceptional, the sound is clear textured and airy. Its sound signature is balanced and quite linear from the lowest to highest frequency. There is very good extension at both frequency extremes, sub-bass and mid-bass are on equal footing but lack quantity - bassheads need look elsewhere. These IEMs have a mature (balanced) tuning, sound refined and sound its best when driven by a quality source. The D6's midrange and treble are the true stars, offering a high level of transparency and excellent detail retrieval without sounding analytical. Soundstaging, imaging, layering, instrument separation are some of its forte. I've seldom heard treble as pristine and airy with a complete absence of glare or stridence. Cymbals, bells, trumpet snare drums all sound really special, they all have correct timbre and natural decay.
Alpha & Delta has done a fine job with this IEM, it has become my new favorite for just about any genre but especially Jazz (vocal or instrumental) acoustic, classical. The D6 is definitely intended for audiophiles.
Would not recommend to a friend.