Audio stuff with Audacity

[alabulei1]

Hello, I am your assistant on GitHub, built by the Second State team. I am ready for your question now!

[The-Bart-The]

If I have two nearly identical audio tracks, the only difference being a voiceover added to one of them, how can I subtract the normal audio track from the one with the voiceover leaving behind only the voiceover itself?  I would like to use the latest version of Audacity.

[alabulei1]

You can achieve this in Audacity by using the "Invert" effect. Here's how you can do it:

1. Import both audio tracks into Audacity.
2. Select the audio track with the voiceover (let's call it Track A).
3. Go to "Effects" in the menu bar and select "Invert."
4. Select the other audio track (let's call it Track B).
5. Go to the "Tracks" menu and select "Mix and Render."
6. Track A and Track B have now been combined with the inverted effect applied to Track A. This will effectively subtract the original audio from the audio with the voiceover, leaving you with just the voiceover.

Remember to save the new track after completing these steps. This method essentially cancels out the common audio between the two tracks, leaving only the difference which, in this case, is the voiceover.

[The-Bart-The]

What happens if the timings of the tracks are slightly out-of-phase; like 25 milliseconds or so?

[alabulei1]

If the audio tracks are slightly out-of-phase due to differences in timing, you may encounter phase cancellation artifacts when attempting to subtract one track from the other using the method I mentioned earlier. This can result in a somewhat distorted or altered sound, especially in the areas where the tracks overlap in time.

In Audacity, there is no built-in feature specifically designed to compensate for this phase misalignment while subtracting one track from another. However, one workaround you could try is to manually align the tracks as closely as possible before applying the subtraction method. You could try adjusting the timing of one of the tracks to achieve better alignment before performing the inversion and mixing steps.

Another approach you might consider is to experiment with different audio editing techniques or third-party plugins that are designed to handle phase discrepancies or enhance audio alignment. Some audio editing software may offer more advanced features for aligning and processing multiple audio tracks with phase differences.

Ultimately, the effectiveness of these methods may vary depending on the specifics of your audio tracks and how significant the phase misalignment is. It may require some trial and error to find the best solution for your particular situation.

[The-Bart-The]

What if the track without voiceover is slightly louder than the one with voiceover, except during the voiceover parts?

[alabulei1]

If the track without the voiceover is slightly louder than the one with the voiceover, it can complicate the process of isolating the voiceover using the subtraction method in Audacity. The difference in volume levels between the two tracks can affect the effectiveness of phase cancellation and may result in some residual audio from the louder track being present in the final output.

However, you can try the following steps to mitigate the impact of the volume difference:

1. Normalize the Audio Tracks: Use the "Normalize" effect in Audacity to adjust the volume levels of the tracks so that they are closer in amplitude. This can help reduce the disparity in volume between the two tracks before applying the subtraction method.

2. Apply Compression: You can also apply compression to the tracks to help even out the volume levels and reduce the dynamic range. This can help make the subtraction process more effective by minimizing the impact of volume differences.

3. Manually Adjust Levels: If needed, you can manually adjust the volume levels of specific sections of the tracks to ensure that the voiceover parts stand out more prominently relative to the background audio.

By taking these steps to normalize, compress, and adjust the volume levels of the tracks, you can improve the chances of successfully isolating the voiceover from the background audio using the subtraction method in Audacity. Experiment with different settings and techniques to find the best balance between the voiceover and background audio in your final output.

[The-Bart-The]

Is there a more effective and automated way?  Using free solutions, but not necessarily Audacity.

[alabulei1]

For a more effective and automated way to separate the voiceover from the background audio, especially when dealing with phase differences and volume variations between the tracks, you can consider using a tool like Spleeter. Spleeter is an open-source AI-powered music source separation tool developed by Deezer.

Here's how you can use Spleeter to isolate the voiceover from the background audio:

1. Install Spleeter: You can download Spleeter from its GitHub repository: https://github.com/deezer/spleeter. Follow the instructions to install it on your computer.

2. Prepare Your Audio Tracks: Ensure that you have your two audio tracks ready - one with the voiceover and one without.

3. Run Spleeter: Run Spleeter via command line or using its GUI version. Spleeter is capable of automatically isolating vocals, drums, bass, and other components of a musical track.

4. Extract the Vocals: Use Spleeter to extract the vocals from the track with the voiceover. This should effectively separate the voiceover from the background audio, even if there are slight phase differences or volume variations between the tracks.

5. Adjust Settings: You can experiment with Spleeter's configuration settings to optimize the separation results based on the characteristics of your audio tracks.

By leveraging the power of AI-based source separation provided by Spleeter, you can achieve more accurate and automated extraction of the voiceover from the background audio, overcoming challenges such as phase misalignment and volume differences. Feel free to explore Spleeter's documentation and resources for more detailed usage instructions and customization options.