User:Crantila/FSC/Recording/DAW Common Elements

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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."

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, most of which are not available in Fedora through standard means. Which of these applications you use should be determined by personal preference, but here are some rough guidelines to help you get started:

• Ardour: the open-source standard for audio manipulation. Compares well with "Cubase", "Pro Tools", and other commercially-available solutions.
• 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 still unsure of where to start, then you may not need a DAW at all:

• If you are looking for a "high-quality" audio application, which is the case for most computer users, then you would probably be better off with Audacity. To take advantage of the benefits of Ardour for audio recording, your computer should be equipped with professional-quality microphones and an aftermarket audio interface.
• All three DAWs covered in this Guide feature an interface that is similar to most DAW software. If you don't already know how to use this style of interface, and you don't have considerable time to learn it, then you should use Audacity for now. You can always return to another DAW for later projects, or even export the clips you recorded in Audacity for use with Ardour, Qtractor, or Rosegarden.
• LilyPond will produce a MIDI-format representation of a score, if you include the following command in the "score" section of your LilyPond file: \midi { } If the outputted file doesn't offer enough creative flexibility, then you can import LilyPond's MIDI file into Qtractor or Rosegarden. By doing so, experienced LilyPond users can greatly decrease the time they spend learning to use the matrix editor or Rosegarden's tricky notation editor.

Key Concepts

There are several key concepts used by most DAW software applications. These are described below.

!! Arrange these thematically !!

Track and Multi-track

A track represents one channel, or a pre-determined collection of simulatneous, inseparable channels. In the DAW's main window, tracks are usually represnted as rows, whereas time is represented by columns. A track may hold multiple regions (also called "clips"), but they cannot be heard simultaneously. 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.

Mixing

Mixing is the process through which recorded audio regions (also called "clips") are coordinated to produce an aesthetically-appealing musical output. Mixing includes the following procedures, among others:

• automation
• adjusting levels
• time-shifting
• filtering
• panning
• adding effects

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

Mastering

Mastering is the process through which a final version for distribution and listening is prepared from the final mix. Mastering can be performed to many target formats, including to CD, to tape, to SuperAudio CD, or to hard drive. Mixing often involves reducing audio from multiple tracks into two channels, for stereo audio, and reducing sample rate and bit rate to formats suitable for the medium. These processes are called "down-mixing." While most physical formats (like CDs) specify the audio data'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.

!! Consider this !!

Recording

Recording is the process of capturing audio regions (also called "clips") into the DAW software, for subsequent mixing and mastering. Recording is a complex process, involving a microphone capturing sound vibrations, sending electrical impulses to the audio interface which translates them into digital signals, and finally sends them to the DAW software. The DAW stores the regions in memory, but also on the hard drive, as required.

The recording procedure can often become long, complex, and stressful. Good techniques for capturing performances - live or in a studio - are very briefly discussed in the Ardour chapter. If you will be doing a lot of recording, it is strongly recommended that an additional resource is used, specific to recording.

Multichannel Audio

?? is this too political, or appropriate ??

Each channel of audio is independent, and is intended to be played by one speaker. Audio was originally recorded with only one channel, producing "monophonic," or "mono" recordings. Beginning in the 1950s, stereophonic recordings gradually replaced monophonic ones. Most sound recordings available today have at least two channels, making them stereophonic. There is a move now towards five- and seven-channel audio recordings, esepcially for movies, which helps to build a feeling of the sound surrounding the listener (thus "surround sound"). Although Audio CDs and headphones used for MP3 players - plus the fact that humans have only two ears - seem to be slowing the trend for recorded music, both Super Audio CDs and DVD Audio discs offer the capability for more than two channels. There are other factors holding back these formats, the most prominent of which is obstacles posed by copy-protection measures put in place by record labels.

Panning and Balance

!! tricky section !!

!! diagram possibly useful !!

Panning is the process of adjusting how much of a track's sound level is sent to each output channel (see "Multichannel Audio"). Assuming a stereophonic setup, you could cause both of the track's channels to be routed to only one speaker. When a track is set for "centre" panning, all of the left channel audio is heard from the "left" speaker, and all of the right channel audio is heard from the "right" speaker. As you adjust towards "left" panning, all of the left channel audio remains heard through the "left" speaker, as well as an increasing portion of the right channel audio. At the same time, the level of the right channel audio is lowered, so that the level of the right channel audio heard from the "left" speaker plus that heard from the "right" speaker is equal to the level of the right channel when the track is set to "centre" panning. The opposite effect happens when a track is adjusted towards "right" panning.

Balance seems to have a similar effect, but it is not quite the same as panning. The two terms are sometimes confused on audio equipment and in popular usage. As you adjust the balance towards the "left" setting, the level of the right channel is reduced, until it can no longer be heard. By contrast, as you adjust the panning towards the "left" setting, the level of the right channel is reduced, but the right channel's audio can still be heard in the left channel. In effect, balance allows you to "turn off" a channel of audio, or to compensate for non-equidistant speakers. Panning, on the other hand, allows you to effectively combine two audio tracks into one, or to partially combine the tracks, so that the audio signal seems to appear somewhere closer to the centre than before adjustment.

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 simply allows the user to keep track of the settings they would change manually during a session, and have them changed automatically. Not only does this allow incredibly complex behaviour that would be impossible if every setting were to be changed by manually, but it allows the user to focus on other things. Most settings can be adjusted automatically, but the most common adjustments are to level and panning.

The most common method of automating a setting is with a graph called an envelope, which is drawn on top of the track. The user automates the selected control by adding and adjusting points on the graph. This method allows for complex, gradual changes of the setting, as well as simple, one-time changes. Automation is usually controlled by means of MIDI signals, for both audio and MIDI tracks. This allows for devices to adjust settings in the DAW, and and vice-versa - you can actually automate your hardware from within your software-based DAW! Of course, the hardware and software must both support this, and be configured to allow it.

Session

!! diagram required: region, track, and session !!

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

Typically, one session is used to hold one song or movement of a musical piece. There is no strict rule as to how much music should be held within one session, but it should probably correspond to the smallest portion of music that you could want to listen to independently, as determined by the style of music being recorded or synthesized.

MIDI Sequencer

A sequencer is a device which, when provided with compatiable musical notation, will produce synthesized music. Perhaps the original example is a player piano, but modern-day sequencers are usually electronic, and usually synthesize music according to MIDI instructions. The two MIDI-focussed DAWs in the Musicians' Guide, Qtractor and Rosegarden, are well-suited to serve as MIDI sequencers, although Ardour is also a capable MIDI sequencer. Furthermore, all three DAWs use MIDI instructions to perform automation.

Synchronization

Synchronization is exactly what it sounds like - synchronizing the operation of multiple tools. Most often this is used to synchronize movement of the transport, and to control automation across applications. This sort of synchronization is typically achieved with MIDI channels that are not used directly for synthesis.

Routing and Multiplexing

!! "Routing audio is... " !!

!! diagram required !!

Routing audio is achieved on Linux primarily by using the JACK Audio Connection Kit, and the QjackCtl graphical front-end. JACK-aware applications (and PulseAudio, if so configured) provide both inputs and output for audio, assigning different names, and allowing different tasks. Ardour and Qtractor make quite extensive use of JACK - Ardour even for internal connections. This allows for maximum flexibility and creative solutions to otherwise-complex problems.

Mutltiplexing is a related process, which involves routing audio from one output to many inputs or vice-versa. It is also used to refer to a DAW's capability to simultaneously produce and record audio or MIDI signals. With JACK, multiplexing is as easily achieved as basic audio routing. It may require special attention to ensure that all inputs and outputs are properly connected.

Time and Time-Shifting

Time in a DAW is measured from 0, marking the start of playback, to an arbitrary place which marks the end of playback. There are many different ways to measure musical time, and most DAWs allow the user to work in whichever happens to suit them best. The purpose for all methods of measuring time is to precisely indicated when an event (whether audio or MIDI) should begin and end.

• Bars (Measures) and Beats: Usually used for MIDI work.
• Minutes and Seconds: Also includes more precise levels; usually used for audio.
• SMPTE Timecode: Invented for high-precision coordination of audio and video, but can be used with audio alone.
• Samples: Relating directly to the format of the underlying audio file, a sample is the shortest possible length of time in an audio file. See THE DIGITAL AUDIO SECTION for more information.

When a region is time-shifted, the time it is triggered in the DAW is changed. This can be used to "align" musical events that are supposed to be perceived as happening together.

Time is represented in the main DAW interface window as progressing horizontally, where the leftmost point to which the window scrolls is considered to be 0.

Region or Clip

Region and clip are synonyms. Different software uses a different word to refer to the same thing. A region (or clip) 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 contained within one track. Regions containing audio signal data usually display a spectrographic representation of that data. Regions containing MIDI signal data usually display a matricial (matrix-based) representation of that data.

Take

One take is the data recorded while the transport is moving, ending when the transport stops. Each time the transport is started, a new take is started. This term relates more to the practices and procedures of recording than of mixing and mastering.

Transport

The transport marks and controls the current time in a session. The transport can be moved forwards or backwards in slow motion, in real time (the same speed as recording and final playback), or in fast motion, like on archaic, tape-based DAWs. The transport can also be moved by clicking with the cursor. The transport is represented on the DAW interface as a vertical line through all tracks. The transport is also the primary means of selecting a portion of audio within the DAW.

Level

!! INCOMPLETE !!

The level of a track, region, or session is experienced by listeners as its "volume." In professional audio situations, levels are measured in decibels (dB), but represented in a manner that is not at first obvious: 0 dB is the absolute maxmimum level desired. Although it is possible to reproduce higher levels, they may become distorted (REALLY??)

Check:

• "Level Practices"
• this, and
• this
• consider adding a section about "jkmeter," but... well... consider it
• maybe this, too

Busses and the Master Bus

!! diagram required !!

Like a motorized bus, an audio bus can be seen as subjecting multiple different inputs to the same procedure. Whereas on a motorized bus, many different passengers are transported to a different geographical location *in the same way*, an audio bus subjects many different audio signals to the same filtering, equalization, level-adjustment, panning, or other effects process. Many different tracks of audio can enter a bus, through multiplexing, but only two channels will be outputted. This allows adjustments to be made to multiple tracks at once.

All audio being routed out of a program usually passes through the master bus. The master bus collects and consolidates all audio and MIDI tracks, allowing for final level adjustments and for simpler mastering. The primary purpose of the master bus is to mix all of the tracks into two channels.