How to Download and Boost Audio in Youtube Vidoes (Guide)

Sometimes the audio in YouTube videos is too quite, take Help Bob Belong for example. This guide shows you how to download YouTube videos and properly amplify their audio using free, open-source tools.

Download the YouTube Video

Prerequisites:

Linux system (or WSL2 on Windows)
Terminal access
Basic command-line familiarity

Steps:

Install yt-dlp and download the video


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 # Install yt-dlp

sudo apt update
sudo apt install yt-dlp

# Download a video (best quality MP4)

yt-dlp -f "bestvideo[ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]" "YOUTUBE_URL" -o input.mp4

# Download just audio (MP3)

yt-dlp -x --audio-format mp3 "YOUTUBE_URL" -o "audio.%(ext)s"

For Android users who prefer a mobile solution:

App: Seal Video/Audio Downloader
Developer: JunkFood02
Source: GitHub Repository
Features:
- Based on yt-dlp engine
- Material You design
- No ads, completely free
- Batch downloads
- Format selection (video/audio only)
- SponsorBlock integration

Installation: Available on F-Droid or download APK from GitHub releases.

flowchart TD
    A[Need to Download YouTube Video] --> B{Choose Your Platform}

    B --> C[Desktop/Laptop]
    B --> D[Android Mobile]
    B --> E[iOS Mobile]

    C --> F[Use yt-dlp<br/>Most reliable & powerful]
    D --> G[Use Seal App<br/>yt-dlp based, no ads]
    E --> H[Use Web Tools<br/>Online converters]

    F --> I[Get input.mp4]
    G --> I
    H --> I

    I --> J[Proceed to Audio Enhancement]

2: Amplify Audio with FFmpeg

Install FFmpeg if needed:

{% highlight bash %}
sudo apt install ffmpeg
{% endhighlight %}

A: Simple Volume Boost


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 # Mild boost (safe, no distortion)

ffmpeg -i input.mp4 -filter:a "volume=5dB" -c:v copy output_mild.mp4

# Strong boost

ffmpeg -i input.mp4 -filter:a "volume=15dB" -c:v copy output_strong.mp4

Note: -c:v copy copies video without re-encoding (faster)

B: Loudness Normalization (Recommended)


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 # Simple normalization

ffmpeg -i input.mp4 -af loudnorm output.mp4

# Advanced normalization with dynamic range compression

ffmpeg -i input.mp4 -af "loudnorm=I=-16:LRA=11:TP=-1.5" -c:v copy output_normalized.mp4

Parameters explained:

I=-16: Target loudness (-16 LUFS for web, -24 for broadcast)
LRA=11: Loudness range (preserves dynamics)
TP=-1.5: True peak limit (prevents clipping)

C: Dynamic Range Compression

{% highlight bash %}
ffmpeg -i input.mp4 -af “compand=attacks=0:points=-80/-80

-30/-10

0/0” -c:v copy output_compressed.mp4
{% endhighlight %}

3. One-Liner Download and Boost


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 yt-dlp -f "best[ext=mp4]" "YOUTUBE_URL" -o - | \
ffmpeg -i pipe: -af "loudnorm=I=-16:LRA=11" -c:v copy output_enhanced.mp4

Once you have output.mp4:

Mobile Messaging: WhatsApp, Telegram, Signal
Cloud Storage: Google Drive, Dropbox, OneDrive
Social Media: Instagram, Twitter, Facebook
Email: Most clients support MP4 attachments

Important Notes

Legal: Only download content you have rights to or is in the public domain
Quality: Loudness normalization may cause slight quality loss
Backup: Always keep original files before processing
Copyright: Respect content creators’ rights

Troubleshooting

Problem: Audio sounds distorted Solution: Reduce boost amount or use loudnorm instead of volume filter

Problem: FFmpeg process is slow Solution: Use -c:v copy to avoid video re-encoding

Problem: yt-dlp doesn’t work with some videos Solution: Update yt-dlp: sudo yt-dlp -U

Additional Resources

Final Recommendation: For most users, ffmpeg -i input.mp4 -af "loudnorm=I=-16:LRA=11" -c:v copy output.mp4 provides the best balance of quality and compatibility.