Hi RohitDman,
welcome to the Apple (user-to-=user) Community.
Re: "Macbook Air 2020 M1 - Speakers Crackling" :
"I'm unsure why this is happening".
You might want to make sure there is nothing blocking the speaker outlets, eg: clean, no covering, or obstructions.
Apple Support articles that may help:
You might want to check these settings are ok:
If you can’t hear sound from your Mac speakers – Apple Support
Change the sound output settings on Mac – Apple Support
Adjust the sound quality in Music on Mac – Apple Support
If your AirPods Pro make crackling or static sounds - Apple Support
Discussion thread (on creaking cracking sound on Mac):
Try this, worked for me - Apple Community
Or
If you are streaming the audio:
Resolve Wi-Fi and Bluetooth issues caused by wireless interference - Apple Support
Hope there is something useful here, towards finding the source of the "crackles".
Else: A new Mac would be under warranty:
You can enter the serial number (eg from the receipt)
in the webpage below to see what info is available:
Check Your Service and Support Coverage - Apple Support
One stop for technical support, Apple hardware service, and software support.
Call Apple Support at 1-800-APLCARE (or use the app)
AppleCare Products - Apple
All the best :-)