They have very good sound for all uses and frequencies, but their construction is quite poor. The microphone sometimes works well, sometimes not, resulting in not being worth it for calls. The worst part is that they break easily, I have bought two pairs and each one lasted about 6 months, which personally is not enough for me. Moreover, during these 6 months, expect to keep them in specific positions, otherwise the sound cuts off. If I were to spend more than 40-50 on headphones in a year, I would recommend going for better ones. The only reason I still use them is because of the exceptional sound they offer.
