Digital Audio Workstations

In defining the audio editor, the software type called Digital Audio Workstation1 _{has been mentioned in the exegesis (see 2.2.1.2: Scope and} appendix 1.1.2: Comparison) but deliberately not explored in detail. So far the discussion has focussed on delineating the software type audio editor, and although most Digital Audio Workstations contain an audio editing section, DAW software itself is distinctively different. Digital Audio Workstations typically include multitrack audio recording and sequencing capabilities, as well as editing and mixing sections. Modern DAW’s include MIDI recording, editing and playback (sometimes in the form of an extensive music notation editor), as well as sophisticated audio routing capabilities and plug-in support for software effects and instruments.

A Digital Audio Workstation can be used for editing audio, but that is just one of its functions. It was kept out of the comparison of audio editor types, because its functions go beyond audio editing. However, though DAW’s were excluded from the discussion what an audio editor is, they (or at least their editing sections) can be included in surveying what an audio editor can do. The complete list of the DAW’s that have been surveyed can be found in the appendices.

Common Ground

Audio editing in a DAW is done at the level of a clip (other names are

region, item, event or object), a single piece of audio positioned on a track. In the

user interface, a clip is represented by a rectangular block, commonly with a waveform drawn into it, that can be dragged and dropped horizontally to a different point along the time axis, or vertically to a different track. Many audio editors (particularly multi-track editors) adopt a similar concept for the visual representation of a segment of audio. Aside from repositioning, a clip can also be trimmed, removing audio from the start or the end. It can be copied and pasted, cut, split, spliced and reversed. A very common feature that is accessible through the graphical user interface of a clip are fades (in and out). These can often be applied simply by dragging the edges of a clip inwards, from a specific corner or handle. Equally common is overall gain adjustment of a clip, which can be applied by either dragging vertically inside the clip, adjusting a gain line that runs through the clip or by adjusting a pop-up gain knob or slider.

Different Scope

The main difference in editing capabilities between audio editors and DAW’s can be attributed to the difference in scope. As described in chapter 2.2.1.2, an [1] The term Digital Audio Workstation historically describes a specialised hardware setup (possibly computer-based) that facilitates recording, editing and producing audio. With the advent of software that was capable of facilitating this in a single application, the term Digital Audio Workstation became a more general term, identifying either hardware or software that facilitates audio recording, editing and producing.

audio editor doesn’t normally use musical markers or reference points, whereas a DAW includes various musical reference points, such as pitch, tempo, metre - its representations are essentially musical. A DAW has a timeline that can be divided in clock time (seconds and minutes) as well as in musical time (beats and bars). Musical tempo and timing are core concepts in DAW’s. Most DAW’s also offer MIDI note sequencing for playing virtual instruments and synthesisers, making tuning also a core concept.

Tempo & Timing

In most DAWs tempo and timing can be controlled very precisely. A bar can be defined, as can tempo, and these can be specified to changed over time. The bars and beats are displayed along the time axis. Beats have a fixed width; a tempo change will make the play-head progress at a different speed over the beats. Audio clips can be positioned freely at any point along the time axis, or snap to bars, beats and subdivisions, easing the synchronisation of clips on different tracks. Snapping makes looping a clip each specific number of beats or bars very easy too. Clip looping is often provided in a similar way to trimming; a clip edge is dragged outwards to loop the audio in the clip to fit the new clip length.

Not only can a clip be snapped to beats, but its individual contents can be independently snapped to beats as well. If a clip contains audio with distinctive transients, these can be analysed and serve as points at which the clip is

effectively split. After this analysis stage, the individual segments can then automatically be moved and quantised to the timeline. It is then also possible to introduce variations to the timing, for instance to add some swing to an otherwise straight drum track.

This process of analysing for transients, splitting up a clip and moving

around its segments can cause gaps to occur between segments. If the recording is really dense or has a distinctive background noise, this might be undesirable. A relatively recent development alleviates this problem. Flex-Time (also

known as Time Warp, Elastic Time and other variations) also analyses a clip for transients, but does not split it up. Instead it allows for individual segments to be time-stretched, allowing some segments to occur earlier or later on in time, while maintaining a continuous clip of audio.

Tuning

Very similar to Flex-Time is Flex-Pitch (also called Elastic Pitch, pitch shift or

pitch correction), a feature present in a growing number of DAW’s. Flex-Pitch can

be applied to monophonic audio recordings. It performs a pitch analysis and then commonly splits the audio clip on distinctive pitch changes, repositioning each segment vertically over a piano-roll to indicate the pitch of each segment. Any deviation from the specified tuning scale will be visible as an offset from the piano-roll grid. Pitch can be adjusted by dragging segments up or down the piano-roll to snap to an exact note, or to a whole different note, allowing for correction of misplayed notes and for recomposition. The pitch of multiple

segments can also be quantised, often in a gradual way (using a slider to vary the approximation towards exact pitches in the tuning scale), allowing for some natural-sounding deviation to remain. Vibrato, often recognized as pitch variation within a segment, can also be removed by straightening a segment to its particular pitch. This pitch straightening sounds particularly unnatural when applied to voice recordings, which is what characterises severe auto-tune as sometimes heard in popular music (when it is used more as an effect instead of a corrective tool). One artist who is well known for making use of this technique (and for naming a popular auto-tune app for iPhone) is T-Pain.

In Search of Perfection

Many DAW’s include a feature which is called Comping (short for

“compilation”). It allows the user to compile an ideal final take of a performance by selecting the best parts of multiple previous takes. Multiple takes can often be recorded in a single recording session by defining a loop region on the timeline. When the play head reaches the end and jumps back to the beginning of the loop region, a new take is recorded and positioned underneath the

previous take (or above, it differs per DAW). The common approach to comping is then to simply select start and end points in a take, and cross-fades between different takes are added automatically. Though comping is regularly used in search of the best available possible take of a musical performance, it is not a musical feature per se, but can just as well be regarded as a convenient cut- ting-and-pasting mechanism.

Another feature that can be found increasingly often in DAWs is more musical. Groove extraction and, related to that, beat replacement are features that are related to the transient detection mentioned in the paragraph on tempo and timing. Given a recording of a drumbeat, the groove can be extracted by analysing the transients and converting this to pure note information (not so much a pitched note, but particularly the timing of each note). This note information can then be used to trigger synthesised or sampled beats of which volume and timing can be quantised or manipulated more precisely.

Corrective Editing

Overall, the audio editing feature set offered by most DAW’s serves a clear purpose: it focuses on corrective edits. The user begins with trimming, slicing and fading, removing any unwanted material. Then using comping, the user selects the best parts of multiple recording takes. The various tempo and timing tools allow the user to arrange everything in sync and in the right rhythm. Finally, everything is harmonized using the tuning tools.

Whereas an audio editor is a fully packed tool shed for multi-purpose audio editing, in which the focus commonly lies on a single audio file, the audio editing in a DAW is very focused on making the many audio clips in a single project work well with each other.

These corrective edits are all on the level of an audio clip. More

track. Though there are many plug-ins that serve a corrective purpose (for tuning, noise removal, gain adjustment), edits in this section are generally referred to as effects and hence as a different division.

For this survey, the following DAW’s have been inspected (in alphabetical order):

Company Software

Ableton Ableton Live

Sony Acid

The Ardour Company Ardour

Bitwig Bitwig Studio

Steinberg Cubase

MOTU Digital Performer

Image Line FL Studio

Apple Garageband

Apple Logic

Acoustica Mixcraft

MuTools MuLab

Steinberg Nuendo

AVID Pro Tools

Cocos Inc. Reaper

Propellerhead Reason

Magix Samplitude Pro

Cakewalk Sonar

PreSonus Studio One

Tracktion Tracktion