Mine match very well with my iMod + Leckerton Audio UHA-6S Mk2.
If you have a home system and amp, they scale very well generally. So far, tube amps haven't worked so well with my ER4S. I'm not sure why.
I have channel imbalance now and then. Vocals seems like they're 30% to the left. But every time it's because of my seal or something not matching in the right ear. I remove the right tip and re-insert it playing with the seal until it matches. You have to get a perfect seal, but you can't allow the seal to cause a great amount of suction. If you do, you lost bass response and can get imbalance. So get the tips to the full depth and wiggle them around in your ear carefully until they start equalizing pressure and then push them a tad if you need to get the full seal again. That's what I do anyway. Sometimes it's just a matter of waiting a minute or two for the pressure to equalize and they become balances. This is true with many iems.
The tympanic membrane is air permeable--slowly--and so any pressure imbalance across the ear drum will equalize after a few minutes. When I read about this I deliberately did an experiment where I created a significant pressure difference--which was not pleasant, sonically or physically--and just waited. It fixed itself after only one song (approx. 4 mintues), which was good to know.
Personally, I really like the small tripple flanges. I tried a bunch of different solutions, including cutting off the first flange from the regular size tripple, as well as the different foams / gliders, and I much prefer the tripple flange. And not just sonically. I find them to be quite comfortable, actually, especially now that they have broken in a bit.
And on another note, I want to warn (or maybe "advise") new ER4 users not to assume that any sonic problems must be solved by jamming the IEM's further into the ear cannal. I was operating under this assumption and then one day, I was still listening to music as I was pulling my ER4's out when I noticed that WOW! the one I was slowly removing sounded noticeably better all of a sudden! I then did the same thing with the other ear and was so pleased with the sound that I listened for another 30-40 minutes. My theory is that it isn't how CLOSE they are that is really the key, but rather how much AIR VOLUME is being trapped inside the ear. This affects the "Q" of the system--I remember from designing my own speakers in high school that if your cabinet size is too small or too large for your driver, then bass response suffers. There's a sweet spot for any given bass transducer--an a closed cabinet, anyway.
So, for those people here with large ear cannal openings, the optimal position for best bass response would be further in. For those of us who use the small tripple flange, and thus who presumably have a smaller ear cannal, it may be that something a little bit back from maximum, nearly-touching-the-ear-drum, position actually sounds BETTER.
But, I can only report on my own experience. Perhaps others do not find this to be true. But in any case, what I can say is that it is worth messing around with all sorts of parameters WHILE MUSIC IS PLAYING to see if you can't find an even better method for your particular ears and preferences.
Yes, all true, but I am one person who will advise you put them in deeper in almost all situations where the sound isn't correct, only because 90% of people i've seen wearing the er4s are clearly wearing them too shallow. You are correct, even I back them off a bit once they are in to get them "just right", however, if you're not at least reaching the reference plane or "must pass this line here" area, you won't get the target response. Once you pass that plane, I suppose the ear acoustics could play an effect. Pressure is huge though. One might not think to wait a minute or two and judge the sound poorly and then try to reinsert or move them around. Essentially, they never let them settle enough to realize the pressurized sound will improve...
All earphones rely on your ear acoustics, but the er4s unfortunately happens to be very dependent on these things more than most others. So it is well worth one's time getting used to them and not writing them off for a good while. They might be missing out and not even realize it.
Your ears will tell you when it's right.. I don't think inserting deeper and deeper is necessarily going to equal better sound. I think we all find that sweet spot in our own good time. I still highly rate my ER4S / C421 / IHIFI-760 pairing very highly, it can compete with my $650 RDB Mini unit and original 1Plus2 here running Tralucent silver cable. The main area those hybrids excel ER4S is soundstage, but not necessarily raw detail extension when driven from the C421 amp. I think ClieOS rates it one of the best pairings he's heard but with a different OP amp to mine.
Let me see if I can find his cheeky post.
I really want an Etymotic one but I can't believe they charge $50.