Robbert van der Helm has developed a number of excellent free plugins, many of which I use regularly in my projects. But out of all of them, the one I find myself relying on the most is the Spectral Compressor. In my opinion, it’s the most powerful and useful plugin in his lineup.
Spectral Compressor is essentially a free alternative to high-end tools like Soothe2, Soundtheory Gullfoss, and other spectral shaping plugins that typically come with a hefty price tag. Despite being completely free, it offers an impressive amount of functionality and customization options.
The plugin operates in the frequency domain, allowing compression to be applied across thousands of narrow frequency bands. This makes it great for surgical control over harshness, muddiness, or dynamic inconsistencies across the spectrum.
Key Features
- Sidechain support – dynamic spectral shaping based on an external signal.
- Morphing capability – morph one sound into the spectral shape of another.
- Adjustable window size and overlap – control the time-frequency resolution.
- Customizable attack and release times – from subtle to aggressive dynamics.
- Real-time spectrum visualization – intuitive and easy to use.
- Cross-platform support – works with VST3 and CLAP on Windows, macOS, and Linux.
In use, the plugin is surprisingly intuitive. It doesn't feel like a "freeware compromise" — instead, it offers everything you'd expect from a professional spectral compressor, without cutting corners.
Conclusion
Overall, Spectral Compressor is an absolute gem. Whether you're mixing, mastering, or sound designing, it’s a highly capable and versatile tool that deserves a place in any audio toolbox. And the fact that it’s free just makes it even more impressive.
My rating
I would give this plugin 5/5.