It took me a while to get used to the X2. Being a fan of vocal I found them a bit too dry for my taste at first. I didn't want to give up on them as they are built well(If a little inconsistent with some QC issues) and had a nice tonality in there somewhere. I decided to get a fairly neutral dap and hook them up to my Little Dot 1+ with Mullard M8100 + M8161 tubes and they have really grown on me. The Mullard tubes are the best paring with the HD650 giving them a beautiful romantic vocal section. With the X2 they bring out that tone which is almost HD600 like.

I enjoy them as much as my old LCD-2 and HE-500 obviously some technical deficiencies but not too much.

Compared to the HD650 they sound a bit more energized up top and down low. Not as mid focused and not as refined as the HD650 as it has some slight treble tizz(Without the Mullard tubes) but, the bass is a tad lower and equally as impacful.