Chosen Solution
Okay, my MacBook Air’s left-hand speaker is weird. It very very muffled and full static when compared to the right. I thought it could be water damage and decided to replace it. I did that myself and it all went well and then went to check and no change on that speaker. It was the same as before not even a single change or improvement. I ran Mac diagnostics, nothing came up. I also reset NVRAM/PRAM as someone had suggestion that might help. Still nothing. I’m at a total loss of what to do. Also, I am 100% sure when I got it first it was working fine.
What do you hear when you plug in a good set of headphones in via the headphone jack? Use the balance control to bias which headphone is playing. Do you hear it with the headphones? If you do then the MacBook Air 13" (Late 2018-Mid 2019) Audio Daughterboard or MacBook Air 13" (Late 2018-Early 2020) Audio Daughterboard Cable to the logic board is the issue. If its clean on both sides, then the logic board speaker cable connector has a problem. Review this guide: MacBook Air 13” Retina Display Late 2018 Audio Board Replacement
