Host-based programs allowing you to build your own synthesizers from virtual modules have been around for a while. Thanks to DUY, Pro Tools TDM and HD owners can now join in the fun.
After a slow start, a good range of virtual instruments is now becoming available for Digidesign's Pro Tools MIDI + Audio sequencer. However, nearly all of these are 'native' programs running on the host computer's CPU, which use the RTAS or HTDM plug-in protocols, and there are still very few synthesis plug-ins that make use of the DSP hardware in Digidesign's TDM and HD systems. This is odd, because DSP-based synths share the same advantages that have made TDM effects plug-ins so successful: they don't drain the host machine's power, and they can offer guaranteed levels of performance. For a long time Access's Virus was the only TDM synthesis plug-in, but it's recently been joined by a couple of competitors. We'll be reviewing McDSP's SynthesizerOne in a forthcoming issue: the focus here is on DUY's SynthSpider.
Based in Spain, DUY are one of the oldest established developers of TDM plug-ins. They are perhaps best known for DSpider, an innovative product which allows you to build your own custom TDM effects plug-ins from a selection of processing modules. SynthSpider extends this approach to synthesis, and is essentially a virtual modular synth along the lines of Native Instruments' Reaktor. Except, of course, that it isn't native: it requires a minimum of a Mix or Mix Plus TDM system with Pro Tools version 5.x or better running on an Apple Mac. It's fully compatible with Digidesign's newer HD hardware, and can also make use of the older DSP Farm cards if they're installed in a Mix system.
SynthSpider is installed from CD-ROM in the usual way, and is authorised using a standard challenge and response system — you get 15 days' grace if you just want to try it out. You'll need either OMS or FreeMIDI to get it working. I used it with the former, and although there are a number of steps involved in setting it up, the manual provides very clear instructions and I encountered no problems.
Once installed, various versions of SynthSpider appear as options for insertion into audio tracks, aux tracks and Master tracks within Pro Tools. The important distinction here is between the basic SynthSpider plug-in, which is a simplified version allowing you to play stored patches and adjust any parameters that have been given slider controls, and the full SynthSpiderAdvanced plug-in, which is used to edit patches and create new ones. Each of these is available in mono-to-mono, mono-to-stereo and stereo-to-stereo versions depending on what kind of track you insert it into.
Getting SynthSpider to receive incoming MIDI data is straightforward, as is choosing presets from the extensive list available. SynthSpider uses its own patch loading and saving system rather than the host sequencer's, and one noticeable feature is that, unlike Reaktor, it makes no distinction between patches — in the sense of different collections of synth modules, slider controls and so forth — and presets, in the sense of different parameter settings for a given patch. This avoids complication, but does mean you need to be careful about how you organise your patch library. A plus point of SynthSpider's proprietary system is that you can automate patch switching in Pro Tools.
Two related problems that can plague virtual synths on native platforms are latency (the delay between pressing a note and hearing the output) and latency jitter (the variation in this latency). A few minutes' messing around demonstrated that these are unlikely to be serious difficulties for SynthSpider users: although not quite as responsive as a hardware synth, it was perfectly playable on my Mix system with a 512-sample buffer size.
There's a decent range of presets covering the whole spectrum of 'virtual analogue' sounds, with occasional excursions into FM and physical modelling territory, plus some neat effects patches and workable but unintelligible vocoders. The stock synth patches are particularly strong on leads and basses, while emulations of real instruments are less successful. A small folder of drum patches demonstrates that SynthSpider can do the 808 thing when required, but it's not that easy to use as a percussion synth, because you can't easily assign (say) kick, snare and hi-hat to different keys on the same MIDI channel.
This is actually a symptom of a more general defect in SynthSpider, which concerns the way DUY have implemented polyphony. When I first tried out SynthSpider I was confused by the fact that although there's a folder of presets labelled 'Analog (PolyPhonic)', none of them seemed to play polyphonically. I visited the System/MIDI dialogue and changed the relevant MIDI channel to Poly, but playback remained obstinately limited to one note at a time.
As a last resort I turned to the manual, and discovered that although it's possible to play SynthSpider polyphonically, each instance of it is usually monophonic. In order to play it polyphonically, in other words, you need to insert as many instances of the plug-in as you require voices of polyphony — and they need to be on different tracks in Pro Tools. This, as I'm sure you can imagine, is a pain. For one thing, if you're like me, you won't always know in advance how many notes of polyphony you're going to want for a given part. On most soft synths, you can increase the number simply by adjusting one parameter. With SynthSpider, you have to create new tracks, insert new instances of the plug-in, route them appropriately within the mix, and so forth.
I say 'usually monophonic' because there are circumstances where it's possible for individual instances of SynthSpider to play more than one sound at once. A patch can include multiple oscillators and multiple MIDI inputs from different channels, so as long as you don't exceed your quota of modules, you can create patches that effectively contain two or three separate synths. This is no use for creating standard polysynths, but some of the presets employ it to combine, for example, a bass synth and a percussion synth.
The polyphony issues arise because SynthSpider is a pretty DSP-hungy plug-in. Each instance takes up half of a Mix card DSP chip, or the whole of an old DSP Farm chip. An entire Mix card will thus give you a maximum of eight notes of polyphony, while an old DSP Farm will provide only four — and not all SynthSpider patches will load if the plug-in is runing on a DSP Farm. DUY explain that TDM DSP load can't be allocated dynamically according to which patch is loaded, so SynthSpider always has to claim enough DSP power to run the most complex possible synth. They also say that they've sacrificed some efficiency for better sound quality.
DUY have at least done their best to minimise the inconvenience to the user, by making it possible to slave instances of SynthSpider to a Master instance. This means that any patch changes or edits you make with the Master instance are automatically copied to its slaves, so you only have to do them once. I suppose SynthSpider's structure also makes it possible for individual voices within a polyphonic part to be panned or effected differently, although I can't imagine many practical applications for this. By default, LFOs and other modulation sources such as noise generators are not shared across the Master and slave instances, so if you hold down one note and then play another, any modulation such as vibrato or tremelo will usually be out of sync between the two notes. However, the main oscillator module is furnished with an (undocumented) 'Sync and Run' option which allows you to sync slave instances to the Master, or to an external clock.
- DUY SynthSpider v1.0.
- Beige 300MHz G3 Apple Mac with 256MB RAM, running Mac OS 9.1.
- Digidesign Mix system running Pro Tools v5.1.3.
The Advanced version of the SynthSpider plug-in provides two modes of operation, Edit and Run. In Run mode, it behaves like the standard playback-only version of the plug-in, except with a larger window. Edit mode, by contrast, is where you get down to the nuts and bolts of constructing your own synths. You can either begin from scratch or load an existing patch to modify, and the manual provides a helpful walkthrough of the process. Oddly, if you don't start with an existing patch, the 'active' patch name within SynthSpider is not updated when you save, so you need to reload the patch again after saving it for the first time.
Editing is carried out using three tools: the pointer, eraser and Patcher. To the left of the editing screen is a palette providing 40 modules, and the primary function of the pointer tool is to pick them up from here and drop them in the required place within the window. Double-clicking on a module with the pointer tool also allows you to set whatever parameters are available for that module. The eraser tool, as its name suggests, allows you to delete modules and patch cords, while the Patcher is used to make audio, MIDI and control connections between modules. You can choose whether the patch cords are displayed as direct point-to-point links, or whether they snake round modules as a series of straight lines and right-angled turns.
All the tools work as they're designed to, but I can't help wondering whether having three of them is the best way of tackling the job in hand. For instance, rather than switching to the eraser tool each time I wanted to delete an item, I'd have found it easier to simply select the offending module or patch cord with the pointer tool and press Delete — but this does nothing. Alternatively, how about having a single 'smart tool' which carries out different functions depending on which modifier key is held down? As it is, you spend a lot of time clicking between the different tool icons.
The 10-step Undo facility comes in pretty handy, though, as does the ability to assign up to four different versions of your creation to tabs along the top of the editor window for instant comparison. There are also some nice shortcuts: Command-clicking on a module's control input, for instance, automatically creates a slider and numeric display for that control.
SynthSpider's palette of modules isn't quite as broad as Reaktor's, but it will still take diehard synth programmers a long time to get bored with it. It wouldn't be possible to create a useful sampler, but the modules available allow you to cover most types of synthesis, from virtual analogue to FM and additive. Oscillators, filters, envelope generators and all the other standard building blocks of subtractive synthesis are well represented, and there are plenty of more unusual modules. Double-clicking with the pointer tool on a module in the edit window brings up a list of parameters for that module: you can set them as you please unless a control source is patched to the relevant input, in which case they're greyed out.
As well as the obvious MIDI controls, there's an analogue-style step sequencer offering up to 32 steps. A Karplus-Strong oscillator is available for creating physically modelled plucked-string sounds, and another unusual oscillator, the Dynamic Wave Generator, provides an output that morphs between four different waveforms. Both this and the standard oscillator offer a wealth of waveform options including the ability to draw your own waveforms and harmonic spectrums with the mouse, although PWM is only available on a separate, dedicated square-wave oscillator. You can also use external SDII audio files and audio inputs from Pro Tools as oscillators, thus making all manner of effect and vocoder patches possible. Other interesting modules include a waveshaper, envelope follower, chorus and pitch tracker, while virtual oscilloscopes and plasma meters help to keep track of what's happening to your signals.
There are limits on the number of each type of module that can be incorporated in a SynthSpider patch, but you're unlikely to run up against them unless you're trying to create a complex multi-voiced instance as mentioned earlier. You can, for example, have up to eight one-pole and eight two-pole filters in a patch, which helps to make up for the fact that there are no four-pole (24dB/octave) filters as standard.
DUY warn that you should keep the master volume down when editing, as it's possible to damage your speakers and your ears by accidentally creating a feedback loop or similar. I'd suggest they implement some sort of panic button in the editor, and I'd add that prolonged SynthSpider editing is also likely to damage your eyes: the editor graphics are pretty small, and can't be zoomed or resized. It's not too difficult to tell the difference between the modules themselves, but the tiny labels on their various inputs and outputs are well-nigh impossible to read. Having said that, I found this less of a problem in practice than I thought I would. Most common modules are used often enough that you quickly learn which connection is which, and editing is greatly aided by an excellent balloon Help system.
In general, despite a few ergonomic niggles, I think most users who know the basics of subtractive synthesis will find patch creation in SynthSpider pretty straightforward. In some ways, the fact that it doesn't offer the complex heirarchy of modules, macros and Ensembles open to Reaktor users actually makes it easier to get to grips with. Likewise, although it's less open-ended than Cycling 74's Max/MSP, it's a lot more immediate. It's flexible enough that it doesn't feel restrictive, but at the same time it's rarely daunting.
TDM plug-ins tend to be costly compared to native alternatives, and SynthSpider is no exception. All the host-based modular synths I can think of, including Reaktor, Virsyn's Tera and AAS's Tassman, weigh in at under half its price; you can even pick up a hardware modular synth, Clavia's Nord Micromodular, for less. On the other hand, many people with TDM systems are still using older Macs which will struggle to run native soft synths, and even those with newer machines may prefer to lighten the load on their CPU. If you're in this position and you're looking for a virtual modular, SynthSpider is the only game in town, and it does its job pretty well. It's straightforward to understand, it's very stable and predictable in use, and it sounds good. Despite the small graphics and constant tool-switching, creating your own synths is a lot of fun, and in sonic terms, SynthSpider is as versatile as you'd expect a modular synth to be. Its hunger for DSP power and the awkwardness of using it polyphonically will restrict its applications to some extent, but if your track is lacking that one killer bass sound, or you need a dose of ear candy to top off your mix, you could well be glad of its presence in your plug-in rack.