B525 contains one microphone which will also be recognized by your system and made available in your application.  Audio quality can be impacted by several factors including network performance, system, application, or the device itself.  In addition, the mics are designed for use at the desk, not in a distance setting like a conference room.
 
To ensure that the B525 mic is working properly, please follow these easy steps:

• Follow the steps under B525 Basic Troubleshooting and verify that the correct driver is listed in Device Manager under “Audio inputs and outputs” and “Sound, video and game controllers” sections (Hyperlink to that section)
• Are the B525 mics properly selected in your application?Sometimes, the audio can default to a laptop mic, if the computer system has one.Double check that B525 is the mic device selected in your app, and if you don’t see it listed, please review the steps in “My device is not recognized by my computer system”
• Ensure the mic level is optimal; adjusting may even correct the issue.
• Try a different application:Try another video conferencing or audio application.Many applications even have a test mode to playback audio for testing purposes.

• Verify that the network or video conferencing service is not the cause of the audio quality issues, by trying a local audio recording application like Windows 10 Voice Recorder (available free on Microsoft Store) and checking the audio quality of the microphone locally

Some additional advanced steps: 
 

• You can try adjusting the mic gain lower or higher by following these steps:
  • For Windows, right click on the speaker icon in the system tray, and select “Recording devices.”
    • The system tray (or "systray") is a section of the taskbars in the Microsoft Windows desktop user interface that is used to display the clock and the icons of certain programs so that a user is continually reminded that they are there and can easily click one of them.In Windows 10, it looks like this:
    • Once you’ve opened “Recording Devices,” right click on the BRO microphone and select “Properties” and then “Levels”
    • Lastly, adjust the Mic array slider higher and lower to reset the gain
    • For Mac, (Placeholder)
• Enable/disable processing:Sometimes the audio processing in the video conferencing application can interfere with mic performance.If your application allows you to enable/disable audio processing, take this step to evaluate if it makes a difference
• If your audio problems persist, please contact technical support