Digidesign Pro Tools 4.0 Digital Audio Workstation

BY J. Arif Verner

With the drop in computer prices, digital audio workstations are a standard fixture in pro studios. And one of the industry's most supported digital workstations is Digidesign Pro Tools. Pro Tools 4.0 is the latest software upgrade by Digidesign, and the program seems to improve substantially with each new version.

Readers new to Pro Tools should know that the program offers an integrated software (and optional hardware) environment that includes non­linear multitrack recording. automated mixing. non­destructive editing and MIDI sequencing. While many engineers have used the program primarily as a mastering and editing tool, its multitrack recording and mixing capabilities have become more significant in this release.

Features/ln use

First and foremost, Pro Tools 4.0 has been rewritten in Power Mac native code. Users of 68000­based Macs can still run the program, however, the results will be slower than that of a PPC­equipped Mac. While supporting both NuBus and PCI Pro Tools hardware, PCI performance is lightning fast-especially the redraw of new version boasts some 30 significant new features. Previous users won't have much of a learning curve, but neophytes will have to work a little. Like the original Pro Tools program. the main work areas include an "edit" and a "mix" window. There is also a small transport window. and memory location points now have their own window. In an ideal world, Pro Tools would run with a two­monitor system-one monitor for the 'edit'' window and the other tor the mix" window. For the rest of us. we'll simply toggle between both screens.

The edit" window is where the tweaking is accomplished. In the track area, waveforms, volumes and pans along with a ton of other features can be edited. Pro Tools 4.0 has increased the number of track resize options from two to five. The options include '"mini," "small," "normal.'' "large" and "jumbo." .So if there are a dozen tracks on the screen and the one being worked on needs to he focused upon, simply increase its height relative to the others. As in previous versions. the "show/hide'', now available on­screen. allows the user to view or remove any combination of' tracks from the screen. Both of these features are very helpful when working with related groups or a large number of tracks-like multiple vocal tracks. Those tracks can be isolated on the monitor screen and resized as necessary.

Many of the changes in this upgrade have occurred in the "edit" window. New to this screen are two vertical columns on either side of the main editing window. Included here are areas for "edit groups," show/hide.'' "audio regions" and MIDI. Another column imported from the "mix" window shows controls such as record, solo, mute, etc. Different areas in the "edit" window can now he extended or hidden. For example. everything can be hidden except the track views. Then the track waveforms could be extended to fill up the screen-helpful for people who don't have large monitors.

Detailed editing has become a lot easier in the new version. Pro Tools 4.0 now incorporates the Sound Designer II Pencil Tool, so editing is as simple as drawing a line. For example, if a spike needs to be eliminated, use the Pencil Tool to draw a line reconnecting the waveform without the spike. The function is very easy. (Pro Tools 4.0 has included other Sound Designer II features, but more on this later).

Also new are crossfades, S­curves and variable custom shapes. Feel free to graphically stretch, bend and position these as needed. Unfortunately, user­defined crossfades cannot be saved at this time. There's also a noise­shaped dithering option to maximize audio quality while minimizing over­quantization on fades. Additionally, the work can be edited in real time. For example, audio can be trimmed, slid, cut, pasted (or whatever) while a piece is playing. If the results aren't satislactory, hit "undo." In the new version of the program, this command will undo the last action taken. However, it's only one undo. I would love to see an option for multiple undos in a future upgrade.

The "mix" window provides an overview of the Pro Tools virtual mixing console. Like the "edit" window, it includes the "show/hide" and "mix groups" column. New to this version is the ability to resize the window, "narrow" or "wide." Depending upon the monitor size, up to 27 channel strips can be viewed on­screen. Also new is a simulated plasma­style metering display. Prior versions were akin to an LED meter. The level controls have a nice new 3­D look to them too. And Digidesign has expanded Pro Tools from a 1 6­mix bus system to 32. This should make TDM users happy.

And speaking of TDM Plug­lns, with a Pro Tools 111 Core System (Disk I/O Card, DSP Farm Card and Pro Tools software plus the 882 or 888 audio interface), they can be taken advantage of. For the uninitiated, TDM stands for Time Division Multiplexing. TDM is a 256­channel, 24­bit data bus providing the connectivity and DSP processing power required for Pro Tools IlI's powerful digital mixing and processing. Digidesign includes six Plug­ins with Version 4.0, including EQ, dynamics, mod/delay, dither, Procrastinator and a new Plug­in for dealing with phase correction. In addition, there are some 60 third party vendors that have been developing Plug­ins-which are increasing rapidly.

There are several real advantages to the TDM architecture. One is keeping the signal processing in the digital domain and the other is automation. Also, a TDM Plug­In can be configured on different tracks with different settings. For example, one track could have a hall reverb and another track could have a room reverb. To do the same thing with outboard gear, two processors would be needed. Hey, that just saved a thousand bucks! Finally, a new Plug­in Settings Librarian allows Plug­in parameters to be saved and recalled in other Pro Tools sessions.

Most TDM Plug­Ins have about a dozen or so parameter settings. While this is adequate for most people, power users may feel a bit limited. Hey, there are a lot of people who program this stuff "up from the ground level" - and you can't power­tweak if there aren't enough parameters. One way around this is to route an external processor through Pro Tools hardware. But this is defeating the purpose. And automation can't be done unless a sequencer is used.

Another quantum leap with Pro Tools 4.0 is the expanded feature set for automation. Virtually all parameters can be automated. So now TDM Plug­Ins can be automated in addition to controlling gain, pan, sends, returns and mutes. This can either be dynamic or snap­shot automation. Also new is the ability to mute soloed tracks with an instantaneous mute/solo response. Solo safe is available for aux tracks; this means that if you solo an aux track, the aux track still plays.

There are three different types of automation write modes: "write," "touch" and "latch." "Write" kicks into automation immediately; "touch" provides touch sensitivity, which enables and disengages automation; "latch" functions like "touch," but won't stop recording automation until the transport is stopped. Visually, automated features move on­screen as programmed in, a la moving faders. Also, faders maintain their relative levels to one another when grouped together - some powerful stuff here. Additionally, automation data can be graphically edited using break­points in the edit window.

Another nice feature is that Digidesign has set up the automation process separately from the audio data. So if a track's automation has to be deleted, don't to worry about accidentally deleting the corresponding audio. They are totally separate entities.

On­screen automation is handled via a mouse controlling the virtual faders, buttons and knobs. For those who want to get physical, Pro Tools 4.0 includes support for external controllers that are available from Penny and Giles, J.L. Cooper and Peavey via MIDI personality files. These hardware interfaces handle automation by utilizing MIDI control with OMS. Also in the works from Digidesign and Mackie Designs is a new Pro Tools controller called the Human User Interface (HUI).

The HUI will feature moving faders and dedicated functions for transport control. The advantage of external controllers is that you can record multiple moves in one easy step. HUI will eventually be able to control other Digidesign DAK applications like those from MOTU, Opcode and Steinberg.

Lastly, the automation can be thinned to minimize the number of break­points. This can simplify life during editing. Also, thinning keeps the computer from bogging down with extraneous data. Keep in mind that thinning automation is not the same as thinning DSP. Therefore, the sonic integrity of the actual audio information is not compromised.

On my Pro Tools wish list would be the ability to implement pure state­based automation. This would enable the user to specify parameter changes in a dialog box and have them automatically implemented. For example, a TDM reverb decay could be increased from a second to three seconds starting at one minute and finishing at one minute and 45 seconds. The program would then calculate the changes over the specified period of time, and it would be mathematically correct. Sometimes this approach is quicker and more efficient than drawing slopes.

Groups play an important part in Pro Tools 4.0. Let s look at some of the improvements. Digidesign has increased the number of possible groups from one to 26. An obvious example would be to group stereo tracks. Generally, they would be worked upon as a pair. However, mono drum tracks could be grouped together for a mix or an edit. Groups can also be nested in one another.

For example, we might want to add one of our drum tracks to a percussion group-no problem. Also new is the ability to designate whether the group belongs in the "mix" window, the "edit" window or both. In prior versions, once a group was created, it automatically existed in both windows. However, there may be situations where the drums are grouped together for a mix, but one of the tracks in the "edit" window needs to be changed. Easily done. Editing can be done without affecting the other "mix" tracks. And to keep things straight, the name of the group and the corresponding tracks in that group are r ighl on the screen.

Another new feature in Pro Tools 4.0 is AudioSuite. Imagine a plug­in architecture that utilizes file­based processing-that's the picture. Like Sound Designer II, AudioSuite handles its DSP while saving to disk. Since AudioSuite and TDM both utilize plug­ins, there might to be some confusion here. What's the difference? TDM Plug­lns do their processing on the DSP Fann Card. This is part of the Pro Tools III Core System.

AudioSuite, on the other hand, utilizes the host CPU. Therefore, it can run straight from Pro Tools 4.0 software-no need for external hardware. This will save thousands for people who don't want to shell out bucks for the Pro Tools III Core System.

But there are other differences. While multiple TDM effects can be used at once, AudioSuite can only do one at a time. However, AudioSuite tracks can be batch processed. Also, TDM Plug­lns and AudioSuite can be mixed and matched. For example, AudioSuite can be used for pitch shifting, and then the pitch­shifted file can be processed via the mixer using a TDM reverb. But remember, AudioSuite is file­based. This means that the processing can only be written to disk. Also, AudioSuite does not support real­time editing or automation-TDM does.

Therefore, only the AudioSuite effect can be "previewed." To make the "preview" more effective, a loop can be created for continuous playback. In my opinion, AudioSuite and TDM should complement one another rather than compete for the spotlight.

If that's not enough, Pro Tools 4.0 now incorporates Sound Designer II features such as AudioSuite Plug­lns. These include "reverse," "normalize," "gain," "pitch shift," "DC offset removal," "time compression/expansion," "invert," "dither" and "duplicate." Previous to 4.0, this two­track recording and editing program was only available as a standalone application. Now you don't have to leave Pro Tools, go to Sound Designer, do your editing and load it back into Pro Tools. It's built in. A wise, good move on Digidesign's part. However, Sound Designer II users may want to wait before throwing their software in the garbage. Pro Tools 4.0 doesn't support EDL­style event editing or 24­bit recording-Sound Designer II does. But isn't that what upgrades are for?

Bet on many TDM developers importing over existing plug­ins to the AudioSuite format; and expect to see new ones. AudioSuite will stretch the user base for the Pro Tools market. If this ain't a windfall for all involved, I don't know what is!

There are way too many other new features to cover them completely in this review. However, let's take a quick look at what else is available.

A pop­up menu allows multiple edit playlists per track. For example, to do multiple takes of a guitar solo without eating up tracks, use this feature. Edit the playlists as need be. A new expanded set of keyboard shortcuts makes navigating around the program more efficient. Engineers involved in multimedia projects will have the ability to choose from numerous sample rate conversion options. In fact, Pro Tools 4.0 can convert, import and export all sample rates, bit depths and file formats. Also built into the program is a feature called the Audio Squeezer. This is an in­line gate, compressor and limiter used to maximize bit and sample rate­reduced audio.

Another new feature is the ability to navigate around the "regions list" with a "finderstyle" search and sort command. This feature shows the results of a specific search inquiry. Search and sort parameters include "size," "date" and "last modified." And finally, "regions" can be batch­processed directly from the "region list." Yes, this can be a real time saver.

For audio engineers involved in sound for picture work, the program adds QuickTime playback capability. There's also support for inexpensive third­party video capture and playback cards. Editing features include "autospot" and "nudge­to­picture." The MachineControl option can be added for external control of tape or video transports via industry­standard Sony 9­pin and V­Lan protocols, allowing audio and video to be scrubbed in sync. Pro Tools 4.0 even lets the user determine the speed of the shuttle (up to 8x), producing an effect similar to varying the speed on an analog tape machine.

Summary

Digidesign engineers did their homework for Version 4.0.'Pro Tools 4.0 is a quantum leap over version 3.0. They've added a ton of new features without increasing the price! At $795, it's a steal. But there's a Catch 22. If you want the other goodies like TDM, you'll need the complete Pro Tools III Core System. And this is going to cost about 10 grand. But then again, that includes an l/O interface, digital recording, mixing, editing and yes, those TDM Plug­Ins.

Plug­ins tend to be cheaper than their rackmount counterparts since there is no hardware involved-only software. Digidesign was smart to create an upgradeable product line. Start with the basic Pro Tools PowerMix software and, after a couple of months, upgrade to the full­blown Pro Tools III Core System.

(Pro Audio Review would like to thank Glyph Technologies for the use of its GTV400­4000RS hard drive­tape backup system for this review.)