[LAU] How do I create a FIR-filter with opensource tools?

Hi! Recently found "Camilla-DSP" https://github.com/HEnquist/camilladsp It's "a tool to create audio processing pipelines for applications such as active crossovers or room correction." I wanted to try out the room correction, but I have to create FIR filters for my speakers. And this is where I got stuck. My setup is as follows: Ubuntu Studio 24.10 RME HDSP 9652 (output 1-8 = 4xHeadphone, output 9-17 connected with amp) Dayton Audio 12-channel Amp (channel 9/10 not connected) 4 2-way-speakers (LF/HF), each chassis directly connected to the amp (channel 1 - 8) 1 Subwoofer, directly connected to the amp (channel 11/12 bridged) Tried to use REW, but I can't make it behave like an usual jack application ("use input 1, output 9"), instead it deals with cryptic sorround nomenclature and doesn't show up on qpwgraph… Now, as I understood it right, my steps are: * Sending a sweep to every speaker chassis, each, and record the output (of each one) through a measurement microphone. (Measurement samplerate = playback samplerate) * "Invert" each file * Make use of those files in "Camilla DSP" Steps missing? Or am I totally wrong, here? What tools can I use? Of course I have to limit the sweeps to frequencies and levels the speaker chassis will survive…! (Especially for the Tweeters) But one thing I don't understand is how the crossover frequencies are set… Maybe someones able to turn the light on… Thanks! And greets! Mitsch