Going with the Grain

Oct 1, 2008 12:00 PM, By Dennis Miller

           
 

TEN GRANULAR-SYNTHESIS PROGRAMS TO SLICE AND DICE YOUR SOUNDS

RTGS-X provides a variety of ways to modify parameters over time, including an Envelope Follower, which will track the amplitude of incoming audio and map the values to parameters of your choosing. It also offers a Morph function that gradually moves values between two groups of settings, as well as four multisegment envelopes that you can use to modify parameter values over time. CrusherX also has a very nifty Morph feature that alters the time it takes (up to 3,600 seconds) to apply a change in a parameter once you click on a button or move a slider (see Web Clip 3), and GrainMill can extract an amplitude envelope from a preexisting audio file and apply it to any parameter you want.

Organik has a two-dimensional grid where you can morph between the settings of the program's four grain Generators in real time, and crusherX has several grids on which you can control parameters in real time. RTGS-X has what is no doubt the most unusual real-time control source in this group. Its Video Controller window is where you pick an input such as a Webcam or an iSight camera and track an object or a light source in the camera's field of view, then specify what program parameter the x and y coordinates of the object will control.

Added Attractions

Though the main purpose of most of these programs is granulating samples or synthetic waveforms, you'll find a few bonus features in some of them. Kenaxis, REplay PLAYer, and RTGS-X, for example, let you insert VST effects into their output, and Kenaxis also has an extensive sample-looping engine and a synth section with two oscillators and a noise generator. Organik includes its own reverb and delay, Cloud Generator offers reverb, and Stochos includes several filtering options. CrusherX has a limiter/expander as well as a reverb and stereo delay line, and RTGS-X also has a limiter and 5-band EQ that allows frequency, amplitude, and Q control via MIDI.

Be aware that many of the programs were created by small, independent developers. Though they are free or relatively inexpensive, they may be lacking in support or thorough documentation. Moreover, there's no guarantee that any of them will continue to be developed by their creators — some have dates that are several years old. But all told, this collection includes a vast array of features for creating colorful and unique sounds, so be sure to give one or more of them a try.

Sinan Bökesoy's Stochos V6 (Mac, free)

Stochos is one of several programs Bökesoy has developed that use granular methods to produce sound. Its control system is based on the interaction of a variety of elements, including a routing matrix where different parameters are matched to one of several different control sources (see Fig. 3). The control sources themselves can be configured to produce a fixed range of values or to use random distribution curves. You can also alter all parameter values in real time using sliders for that purpose (see Web Clip 4).

Stochos has three options for its basic sound sources: samples (Sampleobj), synths (Synthobj), and an oscillator bank (OscBank). To use a sample, you specify the folder that contains the file you want, pick the specific file, then set the sample's base frequency using a number box. There's a loop switch to enable looping and a range selector to specify how much of the sample will be looped. The synth options include FM, RM, additive, and noise, and you can morph between the various methods over a user-specified amount of time. The oscillator bank has somewhat fewer options than the others and uses Max/MSP's oscbank Object as its source. (You'll need the full version of Max/MSP or a runtime version, available at cycling74.com, to use Stochos.)

Stochos cannot record its output to disk, but you can use Cycling '74's free audio router, Soundflower, for the same purpose. Though that's not as easy as having a record feature, it's well worth the effort to explore this versatile program. You might also have a look at Bökesoy's latest project, a new granular tool called Cosmos, which according to its developer has even more “self-evolutionary” capabilities. If you're interested in the topic, Bökesoy's research in granular synthesis is definitely worth following.

CDP GrainMill 1.1 (Win, about $75)

The CDP toolkit (Mac/Win) is one of the most powerful yet underrecognized sound-processing libraries on the market. It offers several hundred functions, many of which work directly on a sound file and others that perform transformations on phase vocoder analysis data prior to resynthesis. Among these functions are a number that use granular techniques, but unlike those, GrainMill, which is Windows only, runs as a standalone application and is the only sound-processing tool sold separately.

GrainMill's strength lies in the powerful time-varying functions you can impose on all of its parameters. The main screen provides access to a simple Range feature that lets you specify start and end values for any parameter; the program will then randomly generate a value between those limits each time it creates a grain. But far more powerful is the Time Contours area, where you can create very complex multisegment envelopes to control any function. The envelopes can be saved to disk in GrainMill's BRK format, then reused on other parameters in the same session or in any future session. GrainMill also lets you assign extreme values for its parameters. Timestretch (and compress), for instance, supports a range from 4/1,000 to 256 times the original.