Removing High Frequency Buzz and Interference from Audio

Description:

Some video cameras, portable recorders, and audio interfaces can impart annoying high frequency noises that could ruin your audio. The Spectral De-noise plug-in in iZotope’s RX audio repair software can help clean up your audio and preserve your tracks.

Sample:

In this piano track, we can hear the high frequency buzz of an audio interface with a grounding problem.

Before RX:

After RX: 

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Plug-in Workflow:

  1. Open the De-noise plug-in as an insert on the track, or as a offline plug-in if you'd like to render the process clip-by-clip.
  2. Select at least one second of pure noise in your audio.
  3. Click Learn inside the plug-in. If using De-noise as an insert, play back the noisy audio clip so the plug-in can analyze the noise. If using De-noise offline, clicking Learn will extract the noise profile automatically.
  4. Now select the complete audio clip that needs repair.
  5. Click Preview to listen to the noise reduction.
  6. Adjust the Reduction amount to taste.
  7. You can also adjust the Quality control. The Fast setting is optimized for use as an insert plug-in for subtle noise reduction across and entire program, while the Best setting is perfect for offline processing with minimal artifacts, however you may find that different settings work better for different noises.
  8. If you want to render your process in the offline plug-in, click Process or Render in the bottom right-hand corner of the plug-in window.

Tips: 

  • Multiple passes at lower settings. If the buzz is prominent in the recording, consider doing a few passes at a lower Reduction setting, instead of one pass with a high Reduction setting. This will yield a more natural result.
  • Try Dialogue De-noise. While the Spectral De-noise module in RX 5 is optimized tackle these particular kinds of noises with remarkable precision, RX Plug-in Pack users can replicate the process using the De-hum and Dialogue De-noise plug-ins to learn the noise profile and remove much of the problem. If Auto mode is not picking up the noise profile the way you’d like, you can switch to Manual mode and adjust the Noise Profile manually. Selecting a small area where just the noise is occurring then pressing the Learn button will give you a good starting place.
  • Listen in context. When reducing a buzz or noise on a single track that's part of a full band performance, remember that low level signals may not be audible once the rest of the instruments in the song are mixed in. Listen to your edits in the context of the mix to make sure you’re not overusing the noise reduction and affecting the character of the song.
  • Reduce more in pauses. If you're battling a particularly stubborn background noise, you can avoid the 'watery' sound commonly associated with overuse of noise reduction by reducing pauses between lines separately with higher reduction settings.

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