From my point of view these are excellent, both in terms of sound and isolation, plus they look extremely elegant.
I am not a 'golden ear' and can't really say much about the harmonics and sound spectrum as I'm really a complete noob here. However even for me I think I'd like a bit more punchy and powerful bass. Nevertheless the sound is basically music to the ears.
I use the comply tips supplied which provide great isolation and comfort. For me the original plastic tips simply don't work, they keep falling-out no matter what size.
My main complaint would be to the ear guides which occasionally lose the cable and the cable needs to be re-inserted, this is just annoying. You can of-course simply don't use them over ear guides, but I want that optimal sound.
I think the price is a little high, but the sound produced is well worth it.
Cons - very little bass, and did I mention not much bass?
After comparing a bunch of headphones, I "almost" fell in love with the Audeo Phonak PFE112.
The mid range of this set is very smooth and high quality. The treble, while slightly laid back and soft, is very open and precise. Although these aren't the airiest set, the treble extends well, albeit at a slightly relaxing tone. The main downfall is the lack of bass. There is good extension into the sub bass, but only at very low levels. You won't be hearing a lot of meat down in the lower regions on these.
That isn't to say they don't have bass. They have nice smooth clean bass that is very capable, however simply not loud enough in level to be flat or reference. At times the sub bass hits nicely and gives good low presence, but mostly things sound a bit thin on the bottom. Pianos and 'bigger' instruments lack the full body that make them sound as realistic as they could.
However, other instruments such as accompaniment guitars and cymbal type percussion sound excellent. Instrument separation is great, details abound and overall they just draw you into the soundscape. There is no sibilance and the overall frequency response curve doesn't have any noticeable dips or spikes that would otherwise detract from the experience. I fell in love with the warm smooth high quality of the set, but couldn't live without the bass presence. They wouldn't need that much more bass, but in the scope of the entire sound it really detracted from me getting the most out of them...
Check out my video review for some visuals and a quick overview.
I'm thinking with an amp that has a bass boost these might really shine better. Otherwise, they would definitely do the best with songs that don't rely as much on a heavy bottom end. Specifically the mid to low bass regions.
Comfort and fit are some of the best I've tried. Very lightweight, very smooth fit. Great seal and noise isolation. Fairly durable, decent case and includes a filter set that allows you to adjust the tone a bit to lean more towards bass. With the filters in place they have a little more bass but at the cost of some of the great mids they have with the normal filters. With the bass filters they are more in line with other IEMs at the price range, but the standard filters really make the tone and details shine (minus the bass).
Do I like this IEM? Yeah.
Do I love them? Nope.
PFE is a single BA IEM, which possess, IMO, the stereotype signature of BAs in the market. The sound signature is about clarity, balanced, and non-fatiguing. While the headstage is quite narrow, the bass is anemic. It's more for casual listening, and well, I'd praise its comfort design. Once hook up onto your ears, you can be sure to forget about it (and sometimes the music too, because it's so inoffensive and to me, unimpressive).
So, do you want to buy this IEM?
If you want something engaging, go elsewhere. See TF10 or others which really shine in a department.
If you champion comfort more than engaging sound signature, this may be yours to ponder.