SotF review
Free, open-source EQ and room-correction software for cross-platform audio workflows.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
SotF is a free, open-source desktop application for music playback, equalization, room correction, headphone optimization, and audio processing. It supports FLAC, MP3, AAC, ALAC, Vorbis, and other common formats, while its Windows, macOS, and Linux availability suits listeners, headphone users, speaker owners, and audio enthusiasts working across desktop platforms. The visual plugin rack adds graph editing and A/B comparison, and the application includes a terminal interface for users who prefer command-line control.
Its strongest case is the depth of its audio workflow. SotF combines parametric and other equalizer plugins with measurement-based room EQ, speaker optimization, and headphone EQ using target curves. It also supports stereo-to-surround upmixing up to 9.1.6 Atmos. On macOS, a HAL driver provides system-wide audio routing, extending processing beyond music playback. That combination makes SotF a fit for listeners who want local, real-time processing and a single environment for room and headphone work rather than a narrowly focused equalizer.
The ecosystem is another practical advantage. SotF can export configurations to CamillaDSP, Equalizer APO, EasyEffects, Wavelet, PipeWire, and Roon, allowing its work to connect with several established audio environments. The trade-off is that system-wide routing is described specifically for macOS, while the broad feature set and terminal interface may require more audio knowledge than a basic EQ utility. Choose SotF if measurement-based optimization, target curves, cross-platform support, and export options matter. Choose a simpler equalizer if you only need quick tone adjustments without room, headphone, routing, or surround workflows.
SotF pros and cons
- Where it wins
- Free and open-source across Windows, macOS, and Linux
- Measurement-based room EQ plus headphone target-curve optimization
- Exports to CamillaDSP, Equalizer APO, EasyEffects, Wavelet, PipeWire, and Roon
- Where it doesn't
- System-wide routing through a HAL driver is limited to macOS
- The broad processing toolkit may exceed the needs of simple EQ users
- Surround upmixing is specified up to 9.1.6 Atmos
SotF fact sheet, pricing and score →
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
Last updated · How we research and update