Vortex Sound Research

I’ve dove headstrong into my first rack but hadn’t realized/known about how hot the audio output is. I effectively have several sound sources which I had planned on plugging into my 1010 Bluebox mixer in independent channels but the signal is distorted. So…I realize there are output modules for attenuation, and I realize there are mixer modules….if I want to have 3-4 independent sound sources attenuated to line-level for my mixer what do I need to add to my rack (I have plenty of space)?

Do most mix “in-rack” with something like a 4-6 channel mixer module out to a single stereo output module? I am unclear on this and checking the guides and searching I see more related to the signal itself and less on best or common practices. Thanks