Audio Modeling SWAM String Sections

SWAM String Sections combines playability with microscopic levels of control over the sound.

If someone had told me when I was a teenager that there would come a day when you could ‘play’ a string instrument in real time, in your DAW, with just a MIDI controller, and that it had a small hard‑disk footprint plus hassle‑free installation, I’d have thought they were a bit mad. Back then, virtual instruments — string or otherwise — were characterised by somewhat accurate representations of the sound they were trying to emulate, dodgy GUIs, and the need to load a different patch if, heaven forbid, you wanted multiple articulations in the same piece. Sophisticated sample libraries improved the landscape greatly, and then came the physical modelling of instruments, designed for real‑time performance and maximum control over as many parameters as possible to make the virtual instrument feel like the real thing. It’s mind‑boggling, quite frankly.

The Power Of Physical Modelling

A leader in this space is the Italian audio software developers Audio Modeling, who previously brought us Solo Strings (reviewed in SOS August 2019), and recently released SWAM String Sections, powered entirely by their SWAM technology. If you’re familiar with physical modelling vs sample‑based libraries, you already know the drill, but anyone who’s new to this, let’s take a moment to explore the difference. Sample‑based libraries offer pre‑recorded samples of real instruments played by musicians; you can get beautiful, ‘sounds‑like‑the‑real‑thing’ samples to work with, but you’ve largely handed over control of phrasing and expressiveness to the musicians who played on the recording. A good library will fulfil your needs in terms of articulation and dynamics options, but you’re still choosing from an existing palette and that may miss the target when it comes to the expressiveness and emotional resonance you’re after — when it comes to music, there’s more than pure technique that makes a piece what it is.

The possible limitations of a sample‑based library can be best explained in sound design terms: say you have a large library of footstep sound effects to choose from and you narrow it down by shoe type (heel), surface (marble) and speed (slow). The element most likely to not match your intent is performance. You want the slow, confident walk of a woman exploring her luxurious new apartment; the sound effect from the library hits all the marks (walking on a marble floor slowly in heels) but you can’t hear the confidence — it just sounds like someone trying to be quiet and failing because, well, heels. This is the difference performance can make, be it in a sound effect, or an instrument sample. A virtual instrument built using physical modelling adds a highly‑controllable performance element to the mix, allowing you, the composer, to ‘perform’ the instrument in real time, which adds a whole new dimension to the sound. (For a deep dive into the technology, check out this SOS article from way back in 1997: sosm.ag/4clJdAX).

This technology makes a difference to your experience in two other obvious ways: storage and performance. SWAM String Sections’ installation is fuss‑free and barely makes a dent in terms of hard disk space (approximately 430MB for the complete bundle with all plug‑in formats), while RAM usage is about 350MB per instrument instance. The instruments support Audio Units, VST, VST3, AAX 64‑bit, Native Instruments Komplete Kontrol, and run as standalone instruments as well.

The Instruments

SWAM String Sections contains a suite of four separate plug‑ins, each dedicated to a group of instruments from the string section of an orchestra — Violins, Violas, Cellos and Double Basses. The Violin section offers an ensemble of four to six players; Cello, Viola and Double Bass offer three to five players per divisi. This allows the composer to build orchestras of different sizes, ranging from chamber to symphony (CPU Gods willing).

All four instrument sections require control of the Expression parameter, so the first step is plugging in your MIDI controller and making sure the parameter is assigned to a strip/fader that you can play comfortably. (Some composers assign dynamics to a breath controller.) This parameter is key to being able to play the instruments; in fact, you won’t be able to generate any sound at all if you’re not set up to control Expression. The next step is to set a healthy monitoring volume so you’re not riding the Expression slider too hard. The user manual makes a special note of this very early on and lets you know that the slider will go red and warn you if the level of Expression stays above 75 percent for too long. After that, set up vibrato control and you’re off to the races.

Within each section, adjust the timing and pitch precision of the virtual musicians to bring a more ‘human’ feel to the playing.

Each section is meant to emulate a real ensemble with each player playing a slightly different instrument, leading to the variations in timbre, intonation and timing that give a section that ‘human’ feel. However, phase issues are inevitable when using a virtual instrument, so when it comes to placing multiple instances of the same section in one project, pay attention to the Divisi Anti‑Phasing parameter, and adjust to prevent phase‑related artefacts.

Any discussion about the tone of the instruments on offer will be subjective because it depends on how you like things to sound, and also on how skilled you are at coaxing sound out of the instruments. Unlike using a sample‑based library, you can’t separate yourself from the sound coming out of the SWAM String Sections instruments. With great playability and control come a great many parameters that have to be skilfully manipulated and it is definitely something that requires practice. That being said, the violas do well in their lower registers; the cellos are evocative with the right expression and vibrato; the violins are to be handled with care in the higher registers (things can get shrill on longer notes); the pizzicato double basses are immediately fun.

Early users of SWAM String Sections will be pleased to note that in the updated version, the ambiguous Players Accuracy knob has been replaced by two settings that enable you to individually adjust timing and pitch precision in order to introduce more variability to each player’s performance, which is responsible for that loose feel that you get when a group of musicians plays together. The settings can be found in the Advanced menu.

Articulation & Expressivity

An issue that kept cropping up was how tricky it was to avoid a portamento articulation when playing legato. This can be controlled either by adjusting the Portamento Max Time parameter (setting it to Off disables portamento entirely), or by remapping the velocity curve to adjust the sensitivity. For articulations like détaché, a sustain pedal is required; spiccato and flautando are possible to perform by adjusting bow lift and bow pressure parameters; some will be disappointed to hear that col legno is not available. Tremolos seem to sound more natural when the Unsynchronized option is selected, instead of Sync (which synchronises the tremolo rate to the current project bpm); the Sordino is so subtle, it barely makes a difference to any real expressivity.

The threshold between portamento and legato is controlled using the Portamento Max Time parameter, with the option to disable portamento entirely by setting it to Off.

Bow pressure, bow position and bow lift are all adjustable, further helping to shape dynamics and tone; also on offer are keyswitch‑assignable harmonics controls, and an alternate fingering menu that lets you select the position of the left hand on the fingerboard. The manual has a clear and helpful guide on how to perform the various articulations and this deserves a shout out because a lot of software user manuals, while intending to be helpful, are most definitely not always clear.

All the parameters you need to control tremolo rate in one place.

Room Simulator

What good is a realistic‑seeming virtual instrument if you have no sense of the space in which it is played? The folks at Audio Modeling have addressed this issue by creating the Room Simulator. Each instrument section comes equipped with the ability to choose the environment in which it is played, and rooms can be chosen based on absorption characteristics of materials and room size. A handy set of presets lets you place the instruments in rooms like Listening Studio (medium absorption, medium size), Cathedral, Concert Hall and Church... you get the idea. You can also adjust exactly where in the room the instruments are placed by changing distance and angle, and select microphone proximity.

In the Room Simulator view, choose a virtual room, adjust mic proximity, and change the placement of your instrument sections by clicking and dragging in real time.

A notable feature is that independent instrument sections ‘talk to each other’ about their room positions. For example, if you have cellos, violins and violas loaded on separate tracks, you can see the position of all the instrument sections in relation to each other by clicking on any one of the interfaces; modifications to all instrument positions are also possible from any one interface. The room selection is global, so a change to the type of room on one track changes the room type for all the other instrument sections — obvious, really, because you do indeed want all your instruments to be in one location.

A special shout out to the architects of SWAM String Sections for going the extra step and making the instruments user‑friendly for blind and visually‑impaired musicians via menus that are accessible to screen readers.

Conclusion

There is no doubt that the learning curve for shaping the sound of SWAM String Sections is steep. There are a lot of parameters that you are able to control, and being able to control them simultaneously is where practice is key. It takes a different kind of skill to make the instruments sound musical, especially if you’re not an experienced performer or don’t come from an orchestral background.

Your assessment of the sound on offer will also depend on the genre of music you’re composing for, and if accuracy and realism are important to your work, you will perceive the SWAM String Sections differently than if you work in a genre or on a project that allows for a more experimental use of sounds.

Also, knowing what contributes to making the instrument sound ‘real’ and not like a synth is really the first step. If you’re new to orchestration, it’s a good idea to go down the rabbit hole of techniques and arrangement best practices, just to understand what you’re aiming for. Doing this might save you the pain of hours spent trying to fix it with EQ because ‘somehow it just doesn’t sound quite right’.

SWAM String Sections offers immense possibilities and, in the right hands, is a great tool to make your musical ideas come to life.

Is the goal to replicate the sound of a real string section? Or is it to utilise this as a tool in your sound library? For every composer/musician that complains about the lack of realism of the sound, there is another composer/musician that can’t believe they can tweak this many parameters and work with orchestral ensembles without leaving their bedroom studio. Simplistic? Maybe, but eventually it all starts with one composer sitting down (is anyone using a standing desk?) and reaching for the tools at hand to create a piece of music that a listener responds to. SWAM String Sections offers immense possibilities and, in the right hands, is a great tool to make your musical ideas come to life.