How can I fix lower volume & static/buzzing noises?

Here's the issue I have with my left earbud:

• Lower volume compared to the right
  • Attempted resetting earbuds, but no effect
  • Attempted Bluetooth re-pairing with mobile device, but no effect
  • Attempted cleaning the device with 98% alcohol, but no effect
• Buzzing and static noise when audio is passed through
  • Buzzing and static can be heard louder when the bass is passed through
  • Original/expected sound can be heard better when the volume is lower

I'm assuming it to be a speaker issue, but I don't know how to fix it, or even get the speaker component. Please correct me if I'm assuming wrong or if anyone has any suggestions.