JACK Audio Connection Kit (JACK) is a professional sound server that provides real-time, low-latency connections for both audio and MIDI data between applications. JACK has been a key piece of infrastructure and the de facto standard for professional audio software on Linux since its inception in 2002.
JACK provides a basic infrastructure for audio applications to communicate with each other and with audio hardware. Through JACK, users are enabled to build powerful systems for signal processing and music production.
JACK provides a patch bay similar to physical patch panels found in A/V installations. The patch bay can be used to quickly change interconnections between program inputs and outputs, allowing simple to complex routing of Sound and control signals such as MIDI.
jackd is better run with realtime priorities.
Realtime possibilities are included in the mainline kernel, so you don't need a custom kernel.
During installation, jackd2 asks whether you want to modify /etc/security/limits.d/audio to bring realtime priorities to the audio group (which is usually fine for a single user desktop usage).
You can re-run dpkg-reconfigure jackd2 later if you need.
As a start, you can manage jackd and your audio channels with the qjackctl software.
https://www.linuxaudio.org/resources.html : linux audio community with documentation and more
https://linuxmao.org : french community of linux audio users