AAS String Studio

Panel B contains the various modules that make up this unique physical string model and allow you to interact with its various parameters.

String Studio uses Applied Acoustics' physical modelling expertise to (in theory) generate the sound of any string instrument. Good or bad vibrations? We find out...

Imagine a magic guitar which can be restrung with anything from two to 64 strings and played with a plectrum, bow, or bouncing hammers at any position along the strings. You can pitch the strings with fingers or add frets, damp them, or shrink or expand the soundboard. You can listen to it acoustically or via a modelled magnetic pickup, and it has built-in multi-effects. You need imagine no longer, since I've been playing this instrument a lot over the last few weeks — it's String Studio, from Applied Acoustic Systems.

When you've experienced the many and varied sounds that it encompasses, 'String Studio' does seem the perfect moniker. However, it's led some musicians to assume that this product was designed to create hyper-realistic orchestral strings to compete with the various vast multisampled libraries now available. In fact, it's a far more versatile synthesizer that physically models a wide range of sounds generated by strings, such as the hammered strings of acoustic pianos, bouncing hammers of instruments like the dulcimer, the bowed strings of the violin family, and the plucked strings of guitar and pizzicato violin. And that's not all — this new AAS engine is also capable of a wide range of ethereal pads, unusual textures, and out-and-out weirdness.

Overview

Applied Acoustics Systems have championed physical modelling for some years now, ever since the first release of their Tassman software synth in 2000, but with String Studio, they've unveiled a completely new acoustic 'engine'. As with their Lounge Lizard electric piano, processor overhead remains comparatively low compared to modular designs like Tassman, and there's plenty of opportunity to allow the user to interact with the engine in real time using MIDI controllers.

String Studio will run on Mac OS X 10.2 or later with a minimum 733MHz G4 processor, while PC users can use Windows 98SE, 2000, or XP with an 800MHz Pentium III or faster. As usual, if you want to run your sequencer and other software synths alongside, the more powerful your processor is, the better. Installation is easy, but unfortunately you have to enter your serial number and go through the now familiar challenge/response routine on the AAS web site before you can play a single note. String Studio can be run in stand-alone mode, or as a plug-in in VSTi, DXi, Audio Units, and RTAS formats inside a suitable host application.

The main display will be familiar to existing AAS customers. There's a strip across the top with options for loading/saving and importing/exporting of presets and preferences, editing functions, and MIDI Link options (more on these later), while the Toolbar beneath it shows the current preset name and MIDI link, maximum polyphony, active MIDI channel, the value of the currently selected control, plus a CPU meter and MIDI activity 'LED'.

The main area is split between the Preset Browser (which can be hidden if preferred) and the main control area. String Studio has a lot of controls in this area, but AAS have managed to pack the majority into two very manageable areas labelled Panel A and B, which you switch between by clicking on one of the three illuminated buttons on the main title bar (the third is Compare, which lets you make comparisons to the original sound when editing presets, and there's also a master level control with stereo level meters). Panel A is the default view, and houses two horizontal rows of modules, mostly featuring fairly traditional-looking rotary knobs (see the box on the right for more details on this panel).

String Things

The more interesting low-level design of your instruments goes on in Panel B, where there are six main modules. Some of their controls are multi-functional and context-sensitive — in other words, the labels below some of the knobs change as you go along, but thankfully this feels quite natural. The most important module is the virtual String, which is permanently 'in circuit'. Its Damp and Decay controls let you adjust the high-frequency content and decay time of the string respectively, to mimic different materials such as nylon or metal, while the Inharm control lets you detune the upper partials, as though you were changing the 'width' of the string.

Additional grey rotary knobs beneath the main controls let you alter the amounts of various modulation signals related to the main controls, and each knob may control and display the values of up to three sources, selected by clicking on one of the green routing 'LEDs' to their right. The modulation signals can also be inverted by clicking on the LED above each knob. For the String Module, the sources are Keyboard (which alters the Damp and Decay values so that the high notes have a shorter decays and more damping), and Ratio, which allows you to adjust decay times for note on and note off, to reproduce the action of dampers on a string.

The string is set into motion by the 'Excitator' module to its left, and this is where you can choose a plectrum, hammer, bow, or bouncing hammer (like those used to play a dulcimer, for instance). This is also where you use the Geometry controls to determine at what position you'll 'play' the string, where the string will be damped (if anywhere), and whether or not its sound will be heard naturally or via the modelled magnetic pickup. The latter is movable along the string so you can achieve bridge or neck sounds.

The remainder of the modules are all optional, and are activated by clicking on the LEDs alongside their title. Beneath the string module is Termination, which models the finger or fret pitching contributions, while above it is the Damper, which adds features for 'stopping' the sound, like virtual felt dampers (as on a piano) or a performer's finger (as on a guitar). The string signal can then pass through the Filter section, where you can add modulation courtesy of the ADSR filter envelope, or put it through a wide variety of more traditional 'analogue' swept filter treatments from subtle to extreme. There are low-pass, band-pass, notch, and high-pass options, a very handy three-peak formant filter for throaty vocal-like sounds, plus a dedicated LFO with a variety of waveforms and sync options.

Next in the signal chain is the Body module, where you can mix in the unique resonances of a range of soundboards ranging from that of a tiny violin to a huge piano, and fine-tune the resonance mix and decay to simulate different materials. This module can add a lot of character. If you want to add a little grit, you can also switch in the Distortion module, which contains a choice of algorithms from mellow to metal. The final module in Panel A is EQ, where you can fine-tune your instruments using a three-band design with low- and high-shelving sections, and a parametric mid section.

In Use

Playing this synth is a joy, and it's easy enough to start creating your own presets by modifying existing ones. However, be prepared for a little initial confusion as you explore the various parameters — this is, after all, a totally unique synth engine, so quite a few of the controls will be unfamiliar. Thankfully most of them make sense fairly quickly once you try them, such as the Stiffness and Protusion of the plectrum, the Force and Friction of the bow, and the Mass and Stiffness of the hammers.

I soon had some lovely acoustic and electric guitar sounds with lots of character and expression, plus a bowed string that resembled the sound of a string quartet, and various ethnic instruments reminiscent of the Japanese koto. However, further exploration proved that the engine could be pushed into unexpected directions — the Bow Excitator, in particular, is capable of creating some wonderful ethereal pads, even before you add EQ and effects, and once you add this final polish you can end up with sounds that I very much doubt you'd achieve elsewhere.

Since this synthesis engine calculates all the sounds in real time as its various modules interact, I found that each note could sound slightly different depending on my performance, just like a real instrument, even before I linked MIDI controllers into the picture to provide even more expression. However, physical modelling is always likely to be more computationally intensive than sample-based synths, so it's important to keep an eye on your maximum polyphony.

You can select the number of voices from a choice of two, four, eight, 12, 16, 20, 24, 28, or 32, although the number of simultaneous notes available is also affected by the Mono/Poly mode and whether Unison mode is active. It's a shame that there's no six-voice setting, since this would be the perfect option for acoustic and electric guitars to avoid wasting CPU power. However, like Lounge Lizard, String Studio has dynamic voice allocation, which means that your CPU need only run those notes that are actually playing. Typically, the overhead for my PC's Pentium 4 2.8GHz processor was 30 percent for four voices, and 50 percent for eight.

If you've not already guessed by this point, I loved String Studio, but although many of the sounds are great fun to play, there are a few parts of the user experience that could definitely be improved. Some of the controls are really tiny (particularly the LEDs next to many controls), making some mouse maneouvres a frustrating experience, and given the amount of virtual wood grain and brushed metalwork in the graphical user interface, perhaps all of the controls could be made larger in a future update. The preset browser also has a fixed width sufficient to view the folder names, but once you open a folder you need to indulge in a lot of sideways scrolling to see the contents. Finally, there's insufficient space to display the full preset and MIDI link names on the menu bar, making it difficult to remember which you've selected, and the MIDI activity indicator disappears completely if you hide the Browser window.

Conclusions

In a perfect world, we'd use a talented guitarist or string player when we wanted these instruments in our songs, but few of us are lucky enough to have such performers on tap all the time. With practice, String Studio can provide some incredibly realistic virtual versions when we have to play in the parts via MIDI, but for me its most exciting aspect is the ability to create new monophonic and polyphonic stringed instruments that sound believable, react to your playing technique like acoustic equivalents, and can be pushed in directions that no other synth can emulate.

You could download the demo version, skim through its presets and not be particularly impressed, but once you start playing this instrument seriously and experience the realistic way it responds to your performance (and particularly once you involve MIDI controllers), you'll be hooked. This is a unique synth that sounds like nothing else on the market.