Thanks for the information, how do you test for the improvement, is the same track, the same volume, the same IEM? I am very curious to know how do you guys measure such improvement? Are the condition kept the same?
Just to add to my own experience and believes, I was very skeptical about wire composition for such a short interconnect wire, we are talking about a few inches here. Well I changed my mind very quickly after building a few of them myself and found different sonic properties depending on the wire material. I have tried pure silver with 1% gold content, pure litz type copper wire and a mix between the two with copper as the ground. The mix ended up being the best combo in terms of bass and brightness (wide spectrum). I am not skeptical anymore. As Vinnie mentionned above, clean soldering techniques, moving marginal components out of the way and best parts will contributube to a better implementation.