I read several reviews on these headphones and makes a non-professional kind of response:
- The sound output is very good quality (bass, treble, crackling and other background noise) on a variety of styles (pop, electro, metal with lots of "drums").
- It is true that the rubber earbuds give an immersion effect that is felt slightly during calls hands-free, but personally, I was not looking handsfree kit troubleshooting but when I run.