Digidesign Structure 1.0 (Mac/Win)

A sampler that integrates with Pro Tools.BONUS MATERIALWeb Clips: Hear audio examples that demonstrate Structure.
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Digidesign has released Structure, an RTAS-based sampler plug-in for Pro Tools HD, LE, TDM, and M-Powered versions 7.3 and later on both Mac and PC. The software is available in three flavors: a full version, which is the focus of this review, and a limited edition and a free version, both of which have smaller feature sets. See Digidesign's Web site for a comparison of features across the different versions.

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FIG. 1: Structure''s patches and parts are organized hierarchically. The patch shown on the right consists of the component parts shown on the left.

Conceptually, Structure is somewhat similar to other plug-in-based samplers, such as MOTU MachFive, Native Instruments Kontakt, and Apple EXS24; however, it is designed to run solely within the Pro Tools environment. If Pro Tools is your DAW of choice, then you will appreciate the tight coupling between this plug-in and the environment.

Like all current-generation software-based samplers, Structure is hungry for speed and RAM. Though 1 GB of RAM is a bare minimum, 2 GB is suggested. The faster the computer, the more simultaneous instruments and voices you will be able to play. Structure is RTAS only, so Pro Tools HD users won't derive much benefit from their TDM hardware and will still need a lickety-split computer to derive maximum benefit. I reviewed this sampler on a dual 2.5 GHz Mac G5 with 2 GB of RAM, Mac OS X 10.4.11, and Pro Tools 7.3.1. Making use of Structure's large patches and effects pushed the CPU to the point where I got dropouts and CPU errors fairly frequently. The situation improved when I expanded the buffer size in the playback engine, and when I bounced tracks to disk and then reimported them whenever I was done working on them.

Structure requires iLok authorization and ships with a 15 GB sample library to get you going. The library is in an encrypted, proprietary format. Every time you load up a new sample set, it takes several seconds to validate your authorization before loading the samples. Structure also ships with a 30-day free trial of the 40 GB Goliath sound library from EastWest ($399; EastWest's Symphonic Orchestra Gold Complete, Structure Edition, is also now available).

Patches and Parts

Structure's hierarchy is based on the notion of patches and parts (see Fig. 1). A patch is an individual instrument with a defined MIDI channel, global volume, and so forth. Patches are made up of an arbitrary number of parts, which can consist of sample sets, effects, MIDI processing modules, and subpatches (patches within patches). The patch window can hold as many patches as computer resources allow, so you can effectively have a single instantiation of Structure host all the sampled instruments in your song. I really like this intuitive, hierarchical solution to grouping and organizing complex bundles of audio data.

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FIG. 2: Structure''s sample editor lets you fine-tune a sample''s start time, end time, and looping range.

Structure uses Digidesign's proprietary format but can also import SampleCell, Kontakt, and EXS24 libraries. Structure patches and individual parts can be saved as separate files. User samples can be saved along with the patches and parts, but any of the samples used in Structure's factory patches cannot. Digidesign has also chosen to use a custom file browser for saving and loading patches, rather than tapping into the Mac's native system. This method takes some getting used to and feels more cumbersome than the Mac's browser.

The included database offers faster file browsing. You can search by category and then refine your search by selecting from a list of keywords, or you can simply type a keyword into the search field. Either way, patches, parts, or samples that fill the bill show up in a selection pane that you can then choose from. As you create your own patches, you can add them to the database, assigning them categories and keywords.

Open Windows

When a sample set is selected, Structure's main window reveals five tabs that provide access to the Part, Filter, Amp, Mod, and Output subwindows. The Part section handles general, global settings such as transposition and key ranges. The Filter section offers some 20 different filter types to choose from. Both the Filter and Amp sections have AHDSR envelopes, with adjustable curves for the attack, hold, decay, and release portions. Note that each sample has its own individual filter and amplifier that work in conjunction with these global ones.

One of my favorite aspects of Structure is its Mod (Matrix Modulation) page. There are 16 slots for various modulation routings. Besides the standard source, destination, and modulation-amount controls, there is an additional modifier section in which another control source can modulate the main source to create even more subtle and complex effects.

An 88-key virtual keyboard and six virtual “smart” knobs take up the lower right-hand area of the main window. You can assign any control parameter to these knobs by simply Ctrl-clicking on the parameter within Structure. A pop-up menu assigns the parameter to the smart knob of your choice. You can even assign multiple parameters to a single smart knob. The smart knob's continuous-controller assignment can also be specified, providing quick, easy control of any sample parameter from your MIDI controller. I love control systems that let you pare down the focus to the parameters you really need, and Structure delivers in this department.

Clicking on the Wave tab when editing a patch brings up the sample editor (see Fig. 2). No new ground is broken here, but the editor's interface is clean and its functions are clearly laid out. You can set sample start and end time, cut and paste audio, set loops and adjust crossfades, and zoom in and out on the waveform.

Sounds Good

The 15 GB factory patch library is a good, solid, overview collection. All the basics are covered: acoustic and electric basses, drums, guitars and pianos, the various instruments of the orchestra, a variety of synth sounds (from leads to pads to bells), organs and vintage keys, drum loops, and ethnic percussion. The acoustic-bass patch has a woodiness that really comes out if you push the Velocity. The Steinway acoustic pianos are mellow and understated — Structure's ability to adjust the hall size using the smart knobs let me quickly tweak the patch to taste. The synth patches are nearly all taken from Digi's Hybrid and Xpand software-synth products.

I laid down a drum performance in Pro Tools with a Roland V-Drum and then assigned the MIDI data to Structure's Vintage Kit XXL patch. The performance made the translation nicely, requiring only some editing of hi-hat data to make it work. This patch's smart knobs allowed for adjustment of direct, room, and overhead mics, as well as reverb size and an SSL talkback-compressor emulation. The sound of this drum kit was open, acoustic, and natural (see Web Clip 1).

Sound Design

As a sound designer, I've long wanted the ability to drag-and-drop regions from Pro Tools into a sampler, where I could quickly tweak sounds in a more intuitive, seat-of-the-pants manner than is possible with third-party plug-ins. With Structure, this is finally possible (for more information, see the online bonus material at emusician.com).

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FIG. 3: The ability to drag-and-drop regions from Pro Tools'' edit window directly into Structure makes it a natural fit for sound designers.

I experimented with creating a Pro Tools session where I grabbed a variety of debris sound elements — bits of ceramic pottery, an old watering can, part of a chain-link fence being dropped on the floor, and so forth — and threw them into Structure (see Fig. 3). Mapping them across the keyboard was quick and easy, and within seconds I was able to experiment with triggering the sample set from my MIDI keyboard in various permutations. Further tweaks with a small dab of convolution reverb to create a sense of distance, and modulating the pan and pitch with a random-number generator source, allowed me to dial in the sound to where I really liked it (see Web Clip 2).

Each Structure patch can have an arbitrary number of insert effects that are routed in series. In addition, there is a global-effects page that features four separate send channels and a global master channel, each of which has four effects slots. This means you can run up to 20 simultaneous global effects within a single instantiation of Structure.

The sampler offers a comprehensive, utilitarian set of effects algorithms, including chorus, compression, distortion, aural enhancement, parametric EQ, flanging, phasing, tremolo, convolution reverb, algorithmic reverb, delay, multitap delay, and rotating speaker. There are also surround versions of the EQ, convolution reverb, and algorithmic reverb, as well as a downmix effect function to collapse a 5.1 patch to stereo. The sound of the effects, on the whole, is good. I especially liked the shimmering multichorus, the optocompressor, and the soupy phaser patches. Of particular interest is the convolution reverb, which lets you use any WAV or AIFF file as an impulse response. Sound designers can quickly and easily experiment with radically changing the character of a sample by setting the convolution reverb's impulse file to exotic, unexpected sounds (see “Master Class: Audio Alchemy” in this issue for more on convolution).

Get Hip

There's no doubt about it: Structure is a hip, powerful, full-featured sampler. The large number of sample parameters, matrix modulation and MIDI processing, comprehensive effects section, and flexible, modular system allow for enough programming power for the most die-hard tweaker. The smart knobs help lessen the complexity of the instrument, letting you control the most important parameters from the front panel. And the good-sized starter library is filled with usable, high-quality samples.

However, I'm not thrilled about the encrypted sample set, Digidesign's use of a custom file browser, or the fact that Structure seems to be hitting the iLok every time you load a patch to verify that you are legally able to. Of course, Structure is limited to use within Pro Tools — if you work with multiple DAWs or like to use standalone sample software, then this is not for you. Finally, like many other current plug-ins, Structure is quite CPU hungry, so owning a fast machine is a must.

If you do work primarily within Pro Tools and are looking for a powerful sampler that integrates cleanly into the system with a minimum of muss and fuss, and particularly if you like the idea of dragging-and-dropping audio regions from Pro Tools right into your sampler, then Structure may just be the solution you're looking for.

Nick Peck is a composer/keyboardist/sound designer in San Mateo, California. His latest album, Fire Trucks I Have Known, is available through CD Baby.


software sampler full version $499 LE version $149 free version $0

PROS: Tightly coupled to Pro Tools. Some excellent sounds in the starter library. Nice-sounding effects, including convolution reverb. Intuitive, flexible patch and parts construction. Supports up to 7.1 surround.

CONS: Pro Tools only. Encrypted sample format. Samples are reauthorized every time you load them. Cumbersome file-loading interface.

FEATURES 1 2 3 4 5 EASE OF USE 1 2 3 4 5 AUDIO QUALITY 1 2 3 4 5 VALUE 1 2 3 4 5

Digidesign, a division of Avid

Web Clips: Hear audio examples that demonstrate Structure.