I’ve had my Etymotic ER4XR in-ears since Christmas, and after the first day I considered returning them - my eardrums were hurting all next day, I was in physical pain from the insertion fit and wondering how such headphones could be allowed to exist on the market. But I had read enough comments about how important it was to find the tips with just the right fit for your eardrums, so I kept trying different fits after my ears recovered - triple flange, double flange, memory foam. I initially thought memory foam was my preference, but some of the sound quality felt lost to me and I was a little annoyed at having to do the squeeze-roll-insert thing each time I put them on. I settled eventually on double flange, small- or -medium sized (I forget which), which I insert fairly deep into my ears, upside down (so the tips are pointing up towards my ear canal), then remove just slightly so that they’re snug and enclose the earhole fully without actually getting into painful territory. I find I get the best possible sound and a full low end this way, without having my ears hurt during and after the experience. I wouldn’t say they’re especially comfortable - I can feel their presence and there’s no mistaking it - but they’re not painful and it becomes second nature eventually.
As far as bass and low end, I have trouble believing anyone could think the ER4XRs don’t offer enough bass. On tracks where the production prioritizes bass, I get as deep and full bass as any headphones I’ve ever used, and it never tips over into distortion or undue misrepresentation to my ears. Listening to Jamie XX right now and yeah, the bass is a physical experience, pretty awesome. My guess is that anyone who isn’t getting enough bass from them is 1) listening to recordings that don’t prioritize bass and thus they want something the musicians/engineers didn’t give them, or 2) they haven’t dialed in the fit properly and are wearing them without a snug, enclosed seal.
My preferred method of listening is also my phone, since another recent purchase was an LG G8X ThinQ. LG is the only phone manufacturer I’m aware of that makes a point of offering a premium audiophile-level quad DAC in their phones (at least the ThinQ series) along with robust settings and configuration for it, and that phone with my custom settings in combination with the excellent sound from the ER4XR ends up being the best listening experience I’ve ever had at home. It’s barely advertised/known but I would choose one of these LG phones over any fancy features of other phones due to the audio quality alone. (They’ve also paid special attention to the microphone, which can get extremely sensitive for a phone mic. There’s even a dedicated “ASMR” mode.)
