Summary: Upgraded from (a lot) of sony low/mid end earphones and headphones to SRH840, the sound was ok but the fit was aweful. Was looking for a small good quality earphones that was not very expensive. These fit the bill perfectly.
Pros: Fit. Excellent sound with Black filters directly from my iPhone.
Cons: Filters need to be replaced - not sure how often or how expensivce they are.
Summary: 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.
Summary: 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.
Summary: 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.