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Preview of SoundSphere

SoundSphere by dzl

SoundSphere boosts quiet tabs up to 800%, shapes sound with Voice/Bass modes and EQ, and shows which Firefox tabs are playing audio — all processed locally with no tracking.

Available on Firefox for Android™Available on Firefox for Android™
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About this extension
SoundSphere is a per-tab volume booster and equalizer for Firefox.

Use it to make quiet videos louder, clean up voices, add bass to music, and quickly find tabs that are playing sound. The popup gives you a volume slider, quick audio modes, a 10-band EQ, and a list of audible tabs with favicons and titles.

Everything runs locally in Firefox. SoundSphere does not use tracking, analytics, remote scripts, or external audio services.

What's New in 1.3
  • Updated the Firefox build to the shared 1.3 release line.
  • Added Firefox for Android compatibility metadata.
  • Improved mobile layout for the popup and options page.
  • Kept the latest Bandcamp and SoundCloud compatibility fixes.
  • Improved fallback behavior for protected or blocked playback.
  • Added explicit no-data-collection disclosure for Firefox Add-ons review.

Features
  • Boost supported tab audio up to 800%.
  • Use Default, Voice, and Bass quick modes.
  • Tune sound with a 10-band equalizer.
  • See playing tabs with an optional toolbar badge.
  • View audible tabs in the popup with favicon and title.
  • Click a playing tab to switch to it.
  • Remember volume per tab, or use one global volume level.
  • Keep settings after Firefox restarts.

Privacy

SoundSphere processes audio locally in your browser.

SoundSphere does not collect browsing history, page content, audio, analytics, or tracking data. It does not send audio or website data to external servers.

Limitations

SoundSphere works best with standard HTML5 audio and video players.

Some services use protected playback, DRM, or browser audio paths that block advanced processing. When that happens, SoundSphere falls back to basic controls where possible so playback stays stable.
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Permissions and data

Required permissions:

  • Access browser tabs
  • Access your data for all websites

Optional permissions:

  • Access your data for all websites

Data collection:

  • The developer says this extension doesn't require data collection.
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More information
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Version
1.3.0
Size
317.62 KB
Last updated
a day ago (Jul 13, 2026)
Related Categories
  • Appearance
  • Photos, Music & Videos
  • Tabs
License
MIT License
Version History
  • See all versions
Tags
  • mp3
  • music
  • youtube
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