Yep same problem. My X5 sat mostly unused for months but worked fine last time I used it. A few weeks ago I started using it again and the scroll wheel is completely wonky. I'm going to contact Fiio and hopefully get this fixed.
The Etymotic founder Dr. Killion essentially defined how the industry measures accuracy: It's really unfortunate that the industry has abandoned quantitative accuracy metrics in favor of connoisseurism.
Yes, but I would not describe the LF "roll off" of the ER4 as typical of other headphones. First, I don't think Headroom's response graphs for deep IEMs is as meaningful as for full size headphones. The graphs from Etymotic look different (http://www.etymotic.com/ephp/er4.html). At 30Hz the response is only -1dB and 20Hz around -2dB and relative to the rest of the curve, this is excellent bass accuracy. The 2k Hz bump is meant to mimic the response of the ear canal...
I suppose it would. I only wear my etys while I am sitting down although I just checked and it seems pretty secure. My etys are pushing 10 years old so maybe my cable is just super flexible and soft which helps it stay in place. I've seen some mods where people use the flexible tubing for hearing aid cables and use it to secure the phones in place over the ear.