Pros: Fairly clean bass, break in time repairs sound hiccups, low price.
Cons: Sparkly treble, cord feels cheap, mids slightly recessed.
The packaging is a royal pain to open. It's nigh upon bulletproof. The cable feels cheap, but has acceptable levels of microphonics. BE WARNED. The headphones themselves sound like crap out of the box. The treble is tinny and uncomfortably loud; the bass lacks extension/clarity. I immediately started them on a break in period of 12 hours at a volume slightly above comfortable listening levels.
Post Break In:
That 12 hour period turns their sound around, and more use will likely continue the trend. I cannot say anything objectively (as my ears may have adjusted), but subjectively it seemed like the tin can treble and shallow bass were repaired. The drivers struggle with midrange detail, but treble sounds have surprising clarity. The treble also remains forward, followed by recessed mids and a solid bass extension. In the words of another reviewer, "These earbuds are good for one thing - spewing gobs of bass." Of course, that sound is achieved with stock tips.
I'm hoping that an upgrade to Comply T-400s will tame the highs, flesh out the mids, and help the lows rumble. Perhaps I'll update this review when I receive them - if the sound balances out a bit more, I would recommend the FX101 to a wider range of buyers. Out of the box they are nothing special, but with a few tweaks the 101s may compete with pricier bass vomiting items.
People looking for a fun and cheap pair of iems with a "V" shaped sound signature, metric tons of bass, and a small soundstage.