SoundFixer is a multimedia extension designed for Firefox that addresses common audio issues found in streaming videos. This subscription-based tool specializes in fixing audio imbalances, allowing users to adjust sound levels that may be too quiet or excessively loud. It aims to provide a better listening experience by correcting audio output that is limited to one channel, offering a more balanced sound through your headphones or speakers.

While SoundFixer works effectively on many platforms, it is important to note that it is not compatible with all websites due to restrictions on the Web Audio API from cross-domain audio sources. However, users can enjoy its benefits on popular sites like YouTube, making it a practical solution for enhancing audio quality during video playback.