I would like to add that editing limits.conf by itself does nothing. You have to raise rt privilages for specific audio interfaces besides the daw itself by special command sudo chrt -a -f -p 50-95 to activate rt processing. Besides of that liquorix is not the best for rt at all. You should install/compile xanmod kernel like i use. Its different versions have different schedulers activated, so research which one do u prefer as for ssd or hdd u need different ones. Also u need killing many non audio processes and services. And all this is a just a small fraction of entire rt art. The deep part is locating bottlenecks in specific os by special tools not available anymore on repos by the way, not even possible to compile them. With fixing bottlenecks 1-2 microseconds latency would be possible. Without it you can count for 7-15 mcs with xanmod which can be about 40 under load but still better than liquorix. Standart rt kernel is about the same latency as xanmod, check which one is more stable for you. Instead of debian use devuan. Dedicating specific cpus for daw via taskset makes things worse - don't bother. Disabling usb hw helps. You can get rt only with pci cards - no usb/firewire. Use midi input not usb for midi input also.
I would like to add that editing limits.conf by itself does nothing. You have to raise rt privilages for specific audio interfaces besides the daw itself by special command sudo chrt -a -f -p 50-95 to activate rt processing. Besides of that liquorix is not the best for rt at all. You should install/compile xanmod kernel like i use. Its different versions have different schedulers activated, so research which one do u prefer as for ssd or hdd u need different ones. Also u need killing many non audio processes and services. And all this is a just a small fraction of entire rt art. The deep part is locating bottlenecks in specific os by special tools not available anymore on repos by the way, not even possible to compile them. With fixing bottlenecks 1-2 microseconds latency would be possible. Without it you can count for 7-15 mcs with xanmod which can be about 40 under load but still better than liquorix. Standart rt kernel is about the same latency as xanmod, check which one is more stable for you. Instead of debian use devuan. Dedicating specific cpus for daw via taskset makes things worse - don't bother. Disabling usb hw helps. You can get rt only with pci cards - no usb/firewire. Use midi input not usb for midi input also.