8. Does the FH19 need to be burned in? How to maintain it in daily use?

Because of the working principle and characteristics of the ear unit's speaker, the speaker diaphragm can be in the best working state after the new earphones are burned in for about 200 hours.

In general, please choose the songs which you often listen to. When you start to burn in headphones, you could choose some soft songs, and set the volume be moderate.