You may experience the same problem that I've just updated to Windows 10 today, everything works wonderfully so far, EXCEPT I've realized the sound is super low. So, how to fix it? The collective methods below could be the most possible solutions to fix low mic volume after the update.
1️⃣ Enable “loudness equalization” (Control Panel-Sound-Playback Device-Enhancement).
2️⃣ Switch to the "Communications" tab under "Sound", make sure ”Do nothing” is selected.
3️⃣ Update/uninstall the audio driver.
Update steps:
Click "Device Manager", then pick "Sound, Video, and Game Controllers".
Right-click "Realtek Audio" and select "Update driver". Then click on "Browse my computer for drivers."
Select from the list of drivers and choose “HD Audio Driver” (do not choose Realtek).
Uninstall Step: Right-click “Realtek”, then choose "Uninstall", and restart the computer.
4️⃣ Go into the “Settings” in your PC, and find Cortana. Turn “Hey Cortana” off. Because Cortana's voice monitoring constantly occupies the microphone channel, it can sometimes cause the microphone to be "locked" or conflict with other software.
5️⃣ Then go into the “Control Panel” and find ”Power Options”. Click on the ”Check High Performance”.
Note: If you hear low-level sound through the headphone or speaker on your PC, the issue could be with only your front or back audio plug, which means one of the jacks is still working normally. So just try to change the audio jack.
If you would like to suggest any other methods or if you have solved the problem in your own way, feel free to let us know via web@fifine.cc!