CamillaDSP

Website: https://github.com/HEnquist/camilladsp

This is open-source software to create audio processing pipelines. What you can do with it:

• Bass management
• Crossover for DIY speakers
• Digital room correction (parametric EQ or convolution)
• Bass and treble tone control (with shelving filters)
• From REW: can import PEQ filters and use wave file for FIR
• Crossfeed for headphones
• Loudness compensation (for listening at lower volumes)
• Switching between inputs (by loading a different configuration)
• Unlimited presets (using separate configurations)

Besides Linux it is also available for Windows and MacOS.

Limitations:

• It does not support multirate decimation for FIR

• GitHub page
• diyaudio.com forum thread