User:Crantila/FSC/Recording/DAW Common Elements

The term Digital Audio Workstation (henceforth DAW) refers to the entire hardware and software setup used for professional (or professional-quality) audio recording, manipulation, synthesis, and production. It originally referred to devices purpose-built for the task, but as personal computers have become more powerful and wide-spread, certain specially-designed personal computers can also be thought of as DAWs. The software running on these computers, especially software capable of multi-track recording, playback, and synthesis, is simply called "DAW software," which is often shortened to "DAW." So, the term "DAW" and its usage are moderately ambiguous, but generally refere to one of the things mentioned.

Knowing Which DAW to Use
The Musicians' Guide covers three widely-used DAWs: Ardour, Qtractor, and Rosegarden. All three use JACK extensively, are highly configurable, share a similar user interface, and allow users to work with both audio and MIDI signals. Many other DAWs exist, including a wide selection of commercially-available solutions. Here is a brief description of the programs documented in this Guide:
 * Ardour: the open-source standard for audio manipulation. Flexible and extensible.
 * Qtractor: a relative new-comer, but easy to use; a "lean and mean," MIDI-focussed DAW. Available from Planet CCRMA at Home or RPM Fusion.
 * Rosegarden: a well-tested, feature-packed workhorse of Linux audio, especially MIDI. Includes a visual score editor for creating MIDI tracks.

If you are unsure of where to start, then you may not need a DAW at all:
 * If you are looking for a high-quality recording application, or a tool for manipulating one audio file at a time, then you would probably be better off with Audacity. This will be the choice of most computer users, especially those new to computer audio, or looking for a quick solution requiring little specialized knowledge.  Audacity is also a good way to get your first computer audio experiences, specifically because it is easier to use than most other audio software.
 * To take full advantage of the features offered by Ardour, Qtractor, and Rosegarden, your computer should be equipped with professional-quality audio equipment, including an after-market audio interface and input devices like microphones. If you do not have access to such equipment, then Audacity may be a better choice for you.
 * If you are simply hoping to create a "MIDI recording" of some sheet music, you are probably better off using LilyPond. This program is designed primarily to create printable sheet music, but it will produce a MIDI-format version of a score if you include the following command in the "score" section of your LilyPond source file:  .  There are a selection of options that can be put in the "midi" section; refer to the LilyPond help files for a listing.

Stages of Recording
There are three main stages involved in the the process of recording something and preparing it for listeners: recording, mixing, and mastering. Each step of the process has distinct characteristics, yet they can sometimes be mixed together.

Recording
Recording is the process of capturing audio regions (also called "clips" or "segments") into the DAW software, for later processing. Recording is a complex process, involving a microphone that captures sound energy, translates it into electrical energy, and transmits it to an audio interface. The audio interface converts the electrical energy into digital singals, and sends it through the operating system to the DAW software. The DAW stores regions in memory and on the hard drive as required. Every time the musicians perform some (or all) of the performance to be recorded, while the DAW is recording, it is considered to be a take. A successful recording usually requires several takes, due to the inconsistencies of musical performance and of the related technological aspects.

Mixing
Mixing is the process through which recorded audio regions (also called "clips") are coordinated to produce an aesthetically-appealing musical output. This usually takes place after recording, but sometimes additional takes will be needed. Mixing often involves reducing audio from multiple tracks into two channels, for stereo audio - a process known as "down-mixing," because it decreases the amount of audio data.

Mixing includes the following procedures, among others:
 * automating effects,
 * adjusting levels,
 * time-shifting,
 * filtering,
 * panning,
 * adding special effects.

When the person performing the mixing decides that they have finished, their finalized production is called the final mix.

Mastering
Mastering is the process through which a version of the final mix is prepared for distribution and listening. Mastering can be performed for many target formats, including CD, tape, SuperAudio CD, or hard drive. Mastering often involves a reduction in the information available in an audio file: audio CDs are commonly recorded with 20- or 24-bit samples, for example, and reduced to 16-bit samples during mastering. While most physical formats (like CDs) also specify the audio signal's format, audio recordings mastered to hard drive can take on many formats, including OGG, FLAC, AIFF, MP3, and many others. This allows the person doing the mastering some flexibility in choosing the quality and file size of the resulting audio.

Even though they are both distinct activities, mixing and mastering sometimes use the same techniques. For example, a mastering technician might apply a specific equalization filter to optimize the audio for a particular physical medium.

More Information
It takes experience and practice to gain the skills involved in successful recording, mixing, and mastering. Further information about these procedures is available from many places, including these web pages:


 * "Mastering your final mix"
 * "Audio mixing (recorded music)"
 * "Multitrack recording"

Interface Vocabulary
Understanding these concepts is essential to understanding how to use the DAW software's interface.

Session
A session is all of the tracks, regions, automation settings, and everything else that goes along with one "file" saved by the DAW software. Some software DAWs manage to hide the entire session within one file, but others instead create a new directory to hold the regions and other data.

Typically, one session is used to hold an entire recording session; it is broken up into individual songs or movements after recording. Sometimes, as in the tutorial examples with the Musicians' Guide, one session holds only one song or movement. There is no strict rule as to how much music should be held within one session, so your personal preference can determine what you do here.

Track and Multi-track
A track represents one channel, or a pre-determined collection of simulatneous, inseparable channels (as is often the case with stereo audio). In the DAW's main window, tracks are usually represnted as rows, whereas time is represented by columns. A track may hold multiple regions, but usually only one of those regions can be heard at a time. The multi-track capability of modern software-based DAWs is one of the reasons for their success. Although each individual track can play only one region at a time, the use of multiple tracks allows the DAW's outputted audio to contain a virtually unlimited number of simultaneous regions. The most powerful aspect of this is that audio does not have to be recorded simultaneously in order to be played back simultaneously; you could sing a duet with yourself, for example.

Region, Clip, or Segment
Region, clip, and segment are synonyms: different software uses a different word to refer to the same thing. A region (or clip or segment) is the portion of audio recorded into one track during one take. Regions are represented in the main DAW interface window as a rectangle, usually coloured, and always contained in only one track. Regions containing audio signal data usually display a spectrographic representation of that data. Regions containing MIDI signal data usually displayed as matrix-based representation of that data.

For the three DAW applications in the Musicians' Guide:
 * Ardour calls them "regions,"
 * Qtractor calls them "clips," and,
 * Rosegarden calls them "segments."

Relationship of Session, Track, and Region
Source image hidden here.

Transport and Playhead
The transport is responsible for managing the current time in a session, and with it the playhead. The playhead marks the point on the timeline from where audio audio would be played, or to where audio would be recorded. The transport controls the playhead, and whether it is set for recording or only playback. The transport can move the playhead forward or backward, in slow motion, fast motion, or real time. In most computer-based DAWs, the playhead can also be moved with the cursor. The playhead is represented on the DAW interface as a vertical line through all tracks. The transport's buttons and displays are usually located in a toolbar at the top of the DAW window, but some people prefer to have the transport controls detached from the main interface, and this is how they appear by default in Rosegarden.

Automation
Automation of the DAW sounds like it might be an advanced topic, or something used to replace decisions made by a human. This is absolutely not the case - automation allows the user to automatically make the same adjustments every time a session is played. This is superior to manual-only control because it allows very precise, gradual, and consistent adjustments, because it relieves you of having to remember the adjustments, and because it allows many more adjustments to be made simultaneously than you could make manually. The reality is that automation allows super-human control of a session. Most settings can be adjusted by means of automation; the most common are the fader and the panner.

The most common method of automating a setting is with a two-dimensional graph called an envelope, which is drawn on top of an audio track, or underneath it in an automation track. The user adds adjustment points by adding and moving points on the graph. This method allows for complex, gradual changes of the seting, as well as simple, one-time changes. Automation is often controlled by means of MIDI signals, for both audio and MIDI tracks. This allows for external devices to adjust settings in the DAW, and vice-versa - you can actually automate your own hardware from within a software-based DAW! Of course, not all hardware supports this, so refer to your device's user manual.

User Interface
!! Hidden bonus info: links to all the images, including *.XCF source image !!

This section describes various components of software-based DAW interfaces. Although th "Qtractor" application is visible in the images, both Ardour and Rosegarden (along with most other DAW software) have an interface that differs only in details, such as which buttons are located where.

"Messages" Pane


The "messages" pane, shown in the above diagram, contains messages produced by the DAW, and sometimes messages produced by software used by the DAW, such as JACK. If an error occurs, or if the DAW does not perform as expected, you should check the "messages" pane for information that may help you to get the desired results. The "messages" pane can also be used to determine whether JACK and the DAW were started successfully, with the options you prefer.

Clock


The clock shows the current place in the file, as indicated by the transport. In the image, you can see that the transport is at the beginning of the session, so the clock indicates "0". This clock is configured to show time in minutes and seconds, so it is a "time clock." Other possible settings for clocks are to show BBT (bars, beats, and ticks - a "MIDI clock"), samples (a "sample clock"), or an SMPTE timecode (used for high-precision synchronization, usually with video - a "timecode clock"). Some DAWs allow the use of multiple clocks simultaneously.

Note that this particular time clock in "Qtractor" also offers information about the MIDI tempo and metre (120.0 beats per minute, and 4/4 metre), along with a quantization setting for MIDI recording.

"Track Info" Pane


The "track info" pane contains information and settings for each track and bus in the session. Here, you can usually adjust settings like the routing of a track's or bus' input and output routing, the instrument, bank, program, and channel of MIDI tracks, and the three buttons shown on this image: "R" for "arm to record," "M" for "mute/silence track's output," and "S" for "solo mode," where only the selected tracks and busses are heard.

The information provided, and the layout of buttons, can change dramatically between DAWs, but they all offer the same basic functionality. Often, right-clicking on a track info box will give access to extended configuration options. Left-clicking on a portion of the track info box that is not a button allows you to select a track without selecting a particular moment in "track" pane.

The "track info" pane does not scroll out of view as the "track" pane is adjusted, but is independent.

"Track" Pane


The "track" pane is the main workspace in a DAW. It shows regions (also called "clips") with a rough overview of the audio wave-form or MIDI notes, allows you to adjust the starting-time and length of regions, and also allows you to assign or re-assign a region to a track. The "track" pane shows the transport as a vertical line; in this image it is the left-most red line in the "track" pane.

Scrolling the "track" pane horizontally allows you to view the regions throughout the session. The left-most point is the start of the session; the right-most point is after the end of the session. Most DAWs allow you to scroll well beyond the end of the session. Scrolling vertically in the "track" pane allows you to view the regions and tracks in a particular time range.

Transport Controls


The transport controls allow you to manipulate the transport in various ways. The shape of the buttons is somewhat standardized; a similar-looking button will usually perform the same function in all DAWs, as well as in consumer electronic devices like CD players and DVD players.

The single, left-pointing arrow with a vertical line will move the transport to the start of the session, without playing or recording any material. In "Qtractor," if there is a blue place-marker between the transport and the start of the session, the transport will skip to the blue place-marker. You can press the button again if you wish to skip to the next blue place-marker or the beginning of the session.

The double left-pointing arrows move the transport in fast motion, towards the start of the session. The double right-pointing arrows move the transport in fast motion, towards the end of the session.

The single, right-pointing arrow with a vertical line will move the transport to the end of the last region currently in a session. In "Qtractor," if there is a blue place-marker between the transport and the end of the last region in the session, the transport will skip to the blue place-marker. You can press the button again if you wish to skip to the next blue place-marker or the end of the last region in the session.

The single, right-pointing arrow is commonly called "play," but it actually moves the transport forward in real-time. When it does this, if the transport is armed for recording, any armed tracks will record. Whether or not the transport is armed, pressing the "play" button causes all un-armed tracks to play all existing regions.

The circular button arms the transport for recording. It is conventionally red in colour. In "Qtractor," the transport can only be armed after at least one track has been armed; to show this, the transport's "arm" button only turns red if a track is armed.