audio editing

Phase is the offset of two waveforms expressed in degrees, where 360 degrees corresponds to a delay of one cycle. Waveforms that are 180 degrees out of phase will cancel each other out to complete silence.

Phase problems can occur when two similar sound sources are out of alignment with each other. This causes the drop out of certain frequencies, which can make recordings sound thin if not dealt with.

Stems is parts of a song exported/bounced separately. So, a regular pop song in stems could for example contain one stem for guitars, one stem for the vocals, one for the drums, and so on. Stems are commonly used when mixing songs that are already arranged and ready, and just need the actual mixing done. It is also what a mixing engineer most likely will ask you for if you decide to have your song mixed professionally.

Modular set ups are where more than one program is used in a set up. JACK allows you to connect and sync various audio programs together so you can benefit from the strengths of individual applications. Session management can be used to manage and recall such complex set ups. A good suite of modular applications is the Non suite, which includes Non timeline, Non mixer and Non sequencer, although any JACK application can be incorporated into a modular set up.

Monolithic set ups are where you do all your work in one program. This is the most common approach people using Windows and Mac audio software will be used to. In Linux, JACK allows for very modular set ups, although some applications are fully featured and can also be used as monolithic set ups, eg. Ardour and Qtractor.

Automation is a system that memorizes and then plays back the position of faders, plugin controls, etc. Automation can be drawn/programmed in, or else inputted in realtime using a mouse or midi controller.

A fader automation lane in Ardour, controlling the level of the fader

A DAW, which stand for Digital Audio Workstation, is software used for the recording, editing and mixing of digital audio. DAW's started off as integrated hardware units but nowadays, a DAW most commonly refers to recording software.

DAW's follow many conventions from hardware recording set ups. You even have a virtual mixer console and can route audio similarly to hardware set ups. You can also process individual audio tracks using plugins such as EQ, compressors and reverbs.

Due to Linux audio's flexibility, very modular set ups are possible. Session management makes this easy by remembering software and their connections. You can launch various programs, connect them up and have you session manager remember, and later, relaunch the whole session, connections included. Some popular session management tools include Non Session Manager (NSM), Ladish and Jack session.