fairphone 3+ (fp3+) sound issue during calls

• /e/ version: 0.16-q-20210422111920-stable-FP3
• Device model(s): FP3+
• Device rooted: no

Summary

i'm experiencing an issue with a fp 3+, /e/ preinstalled. the sound i hear during calls is not good (tinny?!), both through the phone speaker and through a headset (bluetooth) and therefore calls are very unpleasant. i've tried several headsets and calls, no difference. i tried a call via telegram and it seems better.

The problem

Steps to reproduce

make a call

What is the current behavior?

sound during calls is not good (tinny?!)

What is the expected correct behavior?

good sound

Technical informations

Relevant logs (adb logcat)

Relevant screenshots

Solutions

Workaround

Possible fixes