Pros: Airy and spacious, very nice sounding.
Cons: Feels like an insect, not very intimate.
I'd like to voice my opinion on the Etymotic ER-4PT before I pack it up (trading), I didn't really like the sound very much, but it improved significantly with a 75 ohm adaptor (which turns it into the ER-4S) and brought out it's qualities.
The ER-4S is really much more spacious and impressive, it has fantastically clear highs, I love the decay of shimmering cymbals that just extends upward. Imagine that air on every instrument, piano, vocals, there's a really nice sense of air and decay, it's also fairly accurate.
Detailed, I think lends to this signature, that everything appears rather detailed, however I'd like to counter that and (imho) I think there are details that get caught up in the single driver, what I'm saying is they come from the same point in space, there's isn't much layering or imaging and thus detail suffers in this respect, compared to the CK10 I think the CK10 has more detail, and also more speed, in line with the J-phonic (however the J-phonic has speed in the highs and huge decay in the bass, at the same time).
The "microdetail" however (in the way I perceive that term) reminds me of the Shure SRH-940. Listening to the ER-4S and watching the oscilloscope visualizer in foobar at the same time is really fun.
On the negative side, I find myself analyzing the sounds of the music, intead of enjoying the music, so the enjoyment factor is a bit lower than ideal, the intimacy is low, the bass impact is low, and sometimes it feels like a stream of 1's and 0's, however this was even more true of the ER-4PT, I couldn't hear anything but that "1's and 0's" feeling. If the EX1000 is reading romantic litterature, the ER-4 is reading glossary's and phonebooks.
I'm really quite surprised at how much the adaptor improved the ER-4PT.
This is the first song I heard on the ER-4S (ER-4PT with the 75 ohm adaptor), this song is a great match for the ER-4, and I think my amplifier responds better to higher impedance IEM's (which might be tainting this mini-review, since my amplifier made the ER-4S that much better than it's low ohm counterpart).
The design of the packaging was really quite nice (I like the ETYMOTIC red text on the black box) and the FR sheet is something that I really hope other IEM manufacturers pick up on. Just to clarify, it's a frequency response graph of your IEM, with serial codes on the paper that match the serial codes on the ER-4's themselves, as confirmation.
As a final note the design of the IEM's themselves is horrid, it feels like an insect in your ear and you can't wear them over-ear.
The reason I bought the ER-4? http://sonove.angry.jp, thanks Sonove!
My first song experience on the ER-4S, please listen =)