in various other locations on the web, the ER-4S is described as "not good for mobile devices" presumably because of the impedance. Is that correct? I hate to say this, but my primary use for these would be with an iThing, and I don't have the time/patience for faffing with an external amp. My primary goal here is to upgrade from an ancient and failing (ten+ years at this point) set of Etys that provide me with superb noise isolation while I'm in my woodworking shop but I still want enjoyable music and not the deafening roar of saw/dust collection etc.
DistinctiveWoodworkingIf you are using with your iPhone, the Ety hf3 is an isolation champ made for your phone with a 3-button in-line mic/remote. I have many, many different headphones. When I’m mowing the lawn this is my IEM of choice. Works without an amp, controls volume, play/pause/skip, takes calls (best mic of ANY headphone) and blocks out noise like a champ.
Jackstraw335thanks @Jackstraw335 I was hoping for the higher end performance from the ER-4's, but having done more reading: turns out there's a specific version of the ER-4's for iThing's :) Something to keep an Eye on 'Drop' for :)