I will be a first time CIEM buyer, and the reason I am looking into it is because I seem to have a finnicky head. Clamping preasure, headband padding, and pad depth all affect me too much - but with a CIEM I would have none of the issues.
As a first time CIEM hopeful - what can expect from these out of different devices? (ie: An ipod touch, a laptop, etc)
As for what to expect, I can't address the specific details of the C4, but I do own some CIEMs (1964 V.3s) and have listened to lots of UIEMs, working my way up to Etymotic ER-4P and VSonic GR-07 mkII. One of my sources is a 4th Gen iPod Touch. I found that as I moved up in quality IEMs I started wanting a little more out of my iPod. As a result I bought an amp, and then a high quality line-out dock cable. Frankly, I think the combination is what drove me to the V.3s. As I started hearing more and more detail, I got greedy :)
Specifically, I found the iPod alone didn't provide as coherent a sound stage. For example, after upgrading listening to Ray LaMontagne's 'Trouble' I noticed that the instruments move toward the end of the song. It's almost like they're playing on a turntable and it rotates, moving the instruments in relation to each other., I also noticed more sibilance on many tracks. A perfect (extreme) example is Sting's version of Little Wing. And there's also just the pure level of detail. i can now actually understand the mumbling during the intro at the beginning of Pink Floyds 'Wish You Were Here' track from the album of the same name. There's also a subtle inhalation on the left channel just before the guitar picks up that I had never heard before.
Another thing is that i noticed the poor quality recordings in my collection As a result I've done a ton of re-ripping. Most of my 64gb iPhone is full of Apple Lossless. And the rest are basically alll 320kbps mp3s.
Here's the problem though: I can't really say which of the various improvements I've made (better recordings, better cabling/using the line-out dock, getting an amp, and headphone upgrades had made the biggest difference.
I will say that since I got my Vamp I really don't listen to my iPod very much. Finally, as for listening on my laptop, I just really don't do it at all. I've got a relatively low-end Dell which cost about the same as my V.3s, and I don't feel like its audio output is nearly as good as the output directly from my iPod, let alone either of my amped rigs. I suppose I could start investing in a whole other round of enhancements to fix that, but to what point. I guess to have a lot more room for tracks. But really 64gig is lots. I'm not full yet, and I could free up a lot more space by getting rid of a lot of redundant files (how many copies of 'Dark Star' do I really need?)
I hope this ramble helps you.