Instead of introducing spectacular leaps in version updates, the developers of the Ardour free digital audio workstation (DAW) have concentrated on providing many detailed enhancements in the past 12 months.

The third generation of Ardour introduces MIDI tracks and a still experimental video timeline with thumbnails. The project has meanwhile released five new versions and about a dozen bug-squashing updates among other things (see Figure 1).

Figure 1: Nicer, newer, more: The Ardour interface comes with a slew of new enhancements.

Additionally, the functionality of the music production suite is easily enhanced with a variety of extensions (see the "Plugins" box).

Figure 2: Apart from many new synthesizers, many small, well-designed effects are included, such as this simple but clear distorter from dRowAudio.

System Requirements

Ardour's elaborately equipped GTK interface nevertheless requires relatively few system resources. For example, Ubuntu, needs just 2GB RAM to work with the DAW. However, increasing the project size to 20 tracks made the interface rather sluggish in our test, but fortunately did not affect the independent audio engine.

On the software side, Ardour requires a running Jack server. Optimizing the kernel is now merely recommended, whereas it used to be an absolute requirement.

Jack and Ardour run satisfactorily on a normal desktop kernel. However, there's no way around requiring special privileges for the audio mode. You do this by assigning the user to the audio group or, on some systems, the sound or jack group.

Jack inventor Paul Davis warns against installing Jack from the sources themselves. In many cases, this approach leads to problems when Jack and its helper programs run in /usr/local instead of /usr as the package manager intends.

If you want to optimize your system consistently and properly for audio, the Linux Audio wiki [1] has a complete guide.

Many Sources

Ardour is available in most distribution repositories, some of which require including special multimedia package sources. These distribution packages are in a real love-hate relationship with Ardour's chief developer Paul Davis, because the complex suite requires a matching environment and a setup that not all maintainers might implement.

Thus, Ardour works only with an installed and properly running Jack audio server, and the video function requires special video player software. In general, the Ardour project recommends having an already installed and set up the Jack server and only then installing the Ardour package [2] (Figure 3). Most functionalities will work installing from the Ubuntu Software Center, but if you do find anything missing, you should consider installing the packages supplied directly by the Ardour website.

Figure 3: The Ardour installation package installs the suite on /opt, checks the system configuration, and makes suggestions for improvements.

The Ardour install package is behind a pay portal with a requested contribution of at least $1. Any user registered with payment is then relieved of any future update payments. As befits GPLv2 licensed software, the project provides the Ardour source code for Git download.

To install it from there, install the Git client on your system and then execute the following command:

$ git clone git://git.ardour.org/ardour/ardour.git 3.0

This step creates a new 3.0 directory and stores more than 2800 files of over 100MB.

Apart from a list of developer packages [3] required for the build, the Ardour website also has a detailed guide [4] showing how to compile the suite from the sources. However, the guide is targeted to users who aren't first-time Linux software builders and assumes a standard build environment including GCC and tools such as Make.

State of the Art

If you're already familiar with Ardour, the current version 3.5.40 doesn't have much to offer at first glance. However, the application looks better and renders the waveform graphics with nice gradients in the audio region. Minor yet ugly errors, such as text running out of frames, are a thing of the past. The first obvious changes are in the channel views on the left, where the developers made the meters more accurate and configurable.

After loading a project with many MIDI tracks, more audio tracks, and some send channels, many subtle and other more obvious enhancements become apparent. Most of the new switches and controls provide better configuration options or simplify actions that might have been more complicated in previous releases.

The Rhythm Ferret tool, with which you can split individual instrument tracks into separate regions, has been moved from the main menu into the Edit context menu of the audio regions. There you can also find a new tool for removing soft passages in recordings, which automates the chore of removing pauses between words in vocal tracks to reduce the noise in the overall mix.

Owners of large monitors will appreciate the Meterbridge (Figure 4), which shows all the tracks even for very large projects. To enjoy the special features of the software, see the "More Than Just Mouse Clicks" box.

Figure 4: The Meterbridge provides a better overview of all tracks on larger monitors.

Projects also can be continued from those developed with the previous Ardour Series 2. You can open them in the current Ardour, but you will be faced with certain (ugly yet solvable) problems.

Ardour, however, creates a backup of the old material to protect it from serious errors. If, as in the test case, there are only null mixer channels, it's advisable to solve the import errors with onboard tools in the new version.

Digital Sheet Music

The relatively simply designed Ardour MIDI tracks have been improved. You can select the connectivity descriptions for external hardware synthesizers from a list of about a hundred entries.

Among them are not only popular keyboards, such as some Yamaha PSRs, but also some top-range devices such as the Clavia Nord Lead Synthesizer and classics like the Prophet 600, the very first MIDI-compatible synthesizer.

The previously rather abstract matrix for selecting MIDI channels has evolved into a clear and comprehensible dialog (Figure 5).

Figure 5: The new MIDI channel selection in a synthesizer track with expanded automation track used for the synth plugin filter.

Ardour remains true to its classic concept in MIDI tracks, based on methods particularly suited to music played by hand. Composing music in the tracks works well but is simplistic. Certain comfort feature such as automatic key changes, groove templates, or innovative loop functions are missing. MIDI works best in Ardour if you record notes and controller events while playing on a keyboard.

Our test nevertheless showed some difficulties in the MIDI area that should never occur during professional music production. Querying Ardour main developer Paul Davis revealed that one of the problems resulting in a constantly recurring error message (Figure 6) will be solved in a development branch of the program. Thus, it's likely that some of the MIDI problems will be resolved in the next Ardour release.

Figure 6: The message window showed frequent errors in projects with MIDI tracks.

The conditions of the crash indicated that a plugin was responsible. The project involved two instances of Monosynth from the Calf collection; other tone generators used in similar projects caused none of these problems.

An application should be protected against such possible plugin behavior problems. As with all professional applications, you should thoroughly test all relevant tools, including the Ardour plugins, before putting them into production.

Video

Ardour 3 video support consists of two components. The little Harvid server imports video files and transcodes them using Ffmpeg into an optimized format for the player monitor. Harvid also provides thumbnails that appear in the video timeline and that are zoom-dependent: The higher the zoom, the more video frames appear.

The Xjadeo [6] player shows the transcoded video in sync with Ardour's timeline in a window (Figure 7) that you can find under Window | Video monitor . The player and the other aspects of the video functions were largely developed by Robin Gareus for the Ardour project.

Figure 7: The thumbnails in the timeline help provide guidance. The monitor at the lower right shows the video synced with Ardour's timeline.

Because the timeline renders the video down to single frames depending on the zoom level, you can build in sound events very nicely. Short videos can have sound added without needing a script. The software also allows setting marks for placing sound directly during playback, but in many cases the thumbnail reference is enough to find the proper place.

Filmmakers currently demand more than two stereo tracks in the soundtrack. All Ardour channels can be extended to up to 12 tracks. The master channel can then be set up for surround audio, whereby Ardour pops up a tool for spatial arrangement of sound.

Video editing or loading multiple videos aren't a possibility, however. The video function is primarily suited for dubbing previously edited videos.

However, you no longer need to integrate the soundtrack with the video using a program such as Kdenlive. Aside from the well-known export function for the audio mix, the project menu includes an entry that starts a video export function. Unfortunately, setting up the video function is not trivial. The "Getting the Video Function to Work" box explains how to do it.

$ cd /usr/bin
$ sudo su
# ln -s ffprobe ffmpeg_harvid
# ln -s ffprobe ffprobe_harvid

Conclusion

Ardour 3 combines state-of-the-art functionality as well as stability, although it could do with a bit more of the latter. The program provides functionality for an absolutely professional approach to music production that can leave non-free software such as Bitwig Studio behind – at least for classical production of music played by hand.

No other Linux software lets you work as nicely and precisely on music recording. Ardour is a tool for users ranging from audiophiles recording albums on their hard drives, to bands who want to cut and mix their recordings precisely and without problems, to filmmakers who need a tool for perfect soundtracks.