FIG. 1: Control panel B houses the settings for the elements of the physical model.
Physical modeling of acoustic instruments has finally reached the desktop and even the laptop, now that personal computers can handle the required calculations in real time. Applied Acoustics Systems, a leader in physical modeling with its Tassman modular system and Lounge Lizard EP-3 electric piano, has added String Studio VS-1 1.0.1, the winner of EM's 2006 Editors' Choice Award for software synthesizers, to the mix.
String Studio is a virtual instrument that turns your description of a stringed instrument into the equations governing the creation of sound. You decide what sets the string vibrating (pick, hammer, bow), which string characteristics you want to hear (inharmonicity, high-frequency damping, decay), and what instrument body type to use (piano, guitar, or violin, for example). String Studio does the rest.
String Studio comes as a standalone and a plug-in instrument for Mac OS X and Windows. It comes in VST format for both platforms, DXi for Windows, and AU and RTAS for OS X. Challenge-and-response authorization can be carried out online on any computer or by phone.
What's All the Excitement?
Two panels make up the String Studio GUI. Panel A houses performance and global controls such as keyboard settings, the arpeggiator, and the multi-effects chain. Panel B is where you define a stringed instrument's characteristics.
Panel B hosts six modules: Excitator, String, Damper, Termination, Filter, and Body. The Filter, which has a dedicated LFO and an ADSR envelope generator, falls outside of strict physical modeling but adds great variety to the sounds String Studio can produce. Panel B houses a 3-band EQ, a distortion effect, and controls for setting the location of the damper and the excitator relative to the string. The modules are encircled in gray with the ancillary controls close by (see Fig. 1).
The Excitator module determines how the string is set in motion; you choose the type and position of the excitator. The types are plectrum (of which a pick is an example), bow, and hammer (striking the string from above or below). Hammers striking from above can bounce on the string.
Three black knobs below the selection menu control the excitator's characteristics. Gray knobs below the black knobs set modulation amounts for key (MIDI Note Number) and Velocity. The Damp knob at the bottom, which is active only for the plectrum and hammer excitators, varies the damping of the string caused by the impact of the excitator. For example, hard hammers cause less damping than soft ones.
The Geometry settings, above the Excitator module, determine the position of the excitator and the damper. You can specify the position in absolute distance or as a fraction of the string length, and you can modulate position by key and Velocity.
The Pickup knob, below the Excitator module, sets the position of a magnetic pickup relative to the string. Unlike with real electric stringed instruments, the pickup's output can pass through the Filter and Body modules to create a kind of hybrid electric-acoustic instrument. With the Filter and Body modules turned off, the pickup acts as it normally would; with those modules turned on and the Pickup module turned off, the instrument is purely acoustic.
The String's the Thing
The String, Damper, and Termination modules make up the physical model of the string. The String module covers high-frequency damping, overall decay, and inharmonicity of the string. You can modulate high-frequency damping and decay by key. You can also set the ratio between decay and release time, which is a quick way to achieve damping without using the Damper module.
The Damper module controls the damping of the string's vibrations. That's achieved with dampers on a keyboard instrument and with the performer's fingers on other stringed instruments. You have control of the mass and stiffness of the damper, the velocity with which it leaves and returns to the string, and its absorbency. The Gated button controls whether the damper is raised from the string when a key is pressed. Stiff, ungated dampers can bounce on the strings, as can falling hammers.
Termination is the last module in the string triumvirate. It controls the mass of the finger and the stiffness of the finger or fret for instruments that control pitch by terminating the string on a fingerboard.
The body of an acoustic stringed instrument acts as an amplifier as well as a resonant formant filter. String Studio not only models various body types, but it goes one better by offering a resonant multimode filter with envelope and LFO, a 3-band EQ, and distortion.
The filter has 2- or 4-pole lowpass, bandpass, notch, highpass, and formant modes. In formant mode, the Cutoff knob moves all the formants, thereby affecting gender, whereas the Q knob selects between vowel formants. I tried the formant filter on a variety of presets but found it very peaky and almost unusable.
The Distortion module emulates electric-guitar distortion pedals, but it's quite useful on all kinds of sounds. It can add a little roughing up or completely desecrate the sound (see Web Clip 1).
The 3-band EQ, which comes after the distortion effect, is very useful for tweaking the overall sound. The low and high bands are shelving filters, and the middle band is a resonant bandpass filter. Each of the EQ bands has variable frequency and can boost or cut.
FIG. 2: Control panel A contains the effects controls (top) and -controller -settings (bottom).
Globals and Effects
String Studio's Effects section contains chorus, delay, and reverb effects in series (see Fig. 2). A Topology button switches the order of the chorus and delay effects; the reverb always comes last. The chorus and delay have three controls: Mix, Depth, and Rate. The reverb has Mix, Decay, and Color controls.
All three effects have a presets drop-down menu. The chorus presets cover a variety of mono and stereo chorus and flange effects as well as simulated vibrato. The delays include four types of ping-pong, along with tape, digital, slapback, and studio delay emulations. The reverb has typical room presets.
Although rudimentary, the effects are exactly those needed for the types of sounds that String Studio is designed to make. Effects settings are saved with String Studio presets, but you can lock the Effects section so that changing presets doesn't alter the effects settings.
A Clock module, which can be locked, allows String Studio's effects, LFO, and arpeggiator to sync either to an internal tempo setting or to the host's tempo when running as a plug-in. The standalone version has an audio recorder for capturing those magical string moments.
Playing string sounds with a keyboard is always a challenge, and String Studio gives you four modules to help: Vibrato, Portamento, Keyboard, and Arpeggiator. Unlike the simulated vibrato in the Chorus module, Vibrato is an LFO modulating the pitch of the string. You can set delay and fade-in times, the amount of random variation in the vibrato rate, and how much the MIDI Mod Wheel affects vibrato amount (see Web Clip 2).
In addition to octave and semitone transposition and tuning reference, the Keyboard module has a Stretch knob for stretching or shrinking the semitone and an Error knob to introduce random variations in pitch. Unison mode stacks two or four voices per note with adjustable detuning and delay. When the keyboard is in polyphonic mode, you can choose between low, high, and last voice-stealing priority.
FIG. 3: The hierarchical factory preset library covers all stringed-instrument -categories and then some.
String Studio's arpeggiator incorporates a rhythm-pattern generator, which can run free or be synced to tempo. Patterns have as many as 16 steps, and you can toggle individual steps off to create timing gaps in the arpeggio. The currently held chord is arpeggiated in forward, backward, or bidirectional mode (with or without repeated end points). The arpeggio can span as many as five octaves. Arpeggiator patterns are loaded and saved with presets. You can choose from eight rhythm-pattern presets, but you can't save your own.
My one complaint about String Studio is that the buttons on the control panels are hard to hit and the knobs are hard to fine-tune. It's a small thing, but it can be annoying if you're doing a lot of tweaking. On the other hand, the robust MIDI Learn implementation, complete with editable and savable MIDI maps, makes up for it.
The String Studio manual is extremely well written, with lots of graphs and illustrations to clarify the sometimes obscure theory behind the controls. You can download it from the Applied Acoustics Systems Web site before you buy, and it's an enlightening read. Registered String Studio users can also download banks of presets from other users and a master class on using the Damper module.
String Studio delivers a variety of convincing stringed-instrument emulations, but that's not its real charm. It offers a huge sound palette, as its generous preset library attests (see Fig. 3). The library is spread across 17 categories, most named after stringed instruments, but the presets in those categories range from emulations to strange instrument hybrids to unstable sounds that you won't find in nature. And it's easy to make those sounds your own, because the settings you're tweaking call up real-world images that at least hint at what the results might be.
Len Sasso is an associate editor of EM. For an earful, visit his all-new Web site at
APPLIED ACOUSTICS SYSTEMS
String Studio VS-1 1.0.1
|EASE OF USE
|QUALITY OF SOUNDS
RATING PRODUCTS FROM 1 TO 5
PROS: Convincing string emulations. Broad palette of sounds extends far beyond strings. Control panel clearly laid out. Excellent manual.
CONS: Buttons are hard to hit. Can't save arpeggiator rhythm patterns.
Applied Acoustics Systems