I don’t know if you’ve noticed, but the audio in Xiaomi Mi Mix 2S’ recordings is poor. Whereas the call quality is decent, videos and audio clips tend to sound too muffled.
The phone’s aggressive noise cancellation may be causing this. And no, the upcoming MIUI 10 update will not fix this. See, the Mi A1, for example, also suffers from this problem even though it’s not MIUI-based.
Listen to the audio recordings below.
(Rec. 1 comes from a desktop mic while Rec. 2 from Mi Mix 2S. And they’ve all recorded from the same distance. In this exercise, I used the Xiaomi Recorder. You’ll find the app in your phone’s Tools folder.)
Notice the difference? Rec. 2 sounds like its playing from behind a soundproofing foam.
How to increase quality of audio recordings on Mi Mix 2S
So, let’s face it — Xiaomi installed microphones in its devices that are just not capable of handling loud, saturated aural environments.
Fortunately, there are two ways to workaround this shortcoming. One is lengthy (but it doesn’t need root permissions). The shorter one, however, needs root.
I should warn you in advance: this method forces you to synchronize the audio with a video using a third-party tool. So, if you’re not interested in doing some considerably involving editing every time you wish to record a scene head on to Workaround #2.