I live in Hong Kong and there is a shop here provide earphone mod service.   After use the proprietary connectors, I can freely use their original cable or upgrade the cable. I am now using Shure original detachable cable without sound distort.

My e4c was modified to add shure proprietary connector so that it can connect to shure replacement cable. Its hard to find a replacement of e4c's beautiful female vocal on market. See my pictures uploaded for the modified e4c.

I guess the atrix you've tried is 2.3.4 version. My atrix has great sound quality when it's 2.2.2 version.