22. Five filter modes on X5 3rd gen

A: There are 5 kinds of Lowpass filter modes on the X5 3rd gen, and they are Shap Roll-Off Filter, Slow Roll-Off Filter, Short delay Sharp Roll-Off Filter, Short delay Slow Roll-Off Filter and Super Slow Roll-Off Filter. Please go access to "Settings-> Audio settings -> Lowpass filter mode", and then select the filter mode you want.

These 5 kinds of Lowpass filter modes are directly built in the DAC chip AK4490. Here is some official explanations about them from AKM company.  Of course, it is just for reference, after all, the sound quality is very subjective.
Welcome to share your experience about these different filter modes with us.