The Xiaomi Poco M3 is a budget smartphone which was released in November, 2020 and is equipped with a big 6000 mAh battery block, a tripple main camera and a 6.53 inch IPS LCD.
It is necessary for you to clean your speakers. If the issue persists, you can try using a speaker booster app from the Play Store. If that doesn't solve the problem, you may need to replace your speakers.
1 
My phone speaker low volume. Please,help me
bhawesh mohod 의
My speaker have low volume since 3 weeks
Divyansh Porwal 의
I have speaker problem
Hajana 의