Going with the Grain

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

           
 

TEN GRANULAR-SYNTHESIS PROGRAMS TO SLICE AND DICE YOUR SOUNDS

Each Generator has its own volume and pan settings and a mute option, and you can morph between the Generators using a two-dimensional Cube interface. Movements on the Cube can't be recorded, however. Organik includes very serviceable reverb and delay effects, and there's also an LFO with adjustable shape, speed, and amount controls, and a single ADSR global envelope. You can also sprinkle a bit of noise into Organik's output using the Noise generator, which offers Range, Sparse, and Gain settings for that purpose.

Organik is not the most advanced program in this group, but its simple yet elegant approach is a good place to start if you're just entering the granular universe. At this price, there's no reason not to give it a try.

Christopher Keyes's Granular Cloud Generator 2003 (Mac/Win, free)

Cloud Generator is a straightforward program with some interesting variations on the standard grain-generation practice. It supports four audio output channels and can record its output to WAV, SND, or AIFF format, regardless of which platform you're running on. In addition to loading a sample, the program provides a sine wave with variable frequency for synthetic grains. It will generate grains up to 500 ms in length and can produce up to 16 simultaneous grain streams.

The Automation Controls window is the engine for grain generation. At the top of this area is a single row of grain-generating parameters that you can configure and then use for the task. But just below that is another area where you can assign beginning, middle, and end values to all or only some of the same parameters, then determine how long the program takes to move from one set to another. (It would be nice if the values you set above could automatically be assigned to the start row below.)

The Transpositions/Frequencies window gives you a lot of options for controlling grain pitch (see Fig. 6). If you set the Pitch mode to Hertz, you can then type in or move the sliders to enter the exact frequencies you want for each pair of grain streams (each slider controls two grain streams; see Web Clip 8). Choose Cents, on the other hand, and you can transpose the original pitch of the sample in increments as small as 1 cent (1/100 of a semitone). Buttons above the main sliders force the sliders to move in increments of 1s, 10s, or 100s of whichever value you are adjusting. A separate control toggles between synchronous (pitched or semipitched) or asynchronous (nonpitched) grain generation.

The values in the Transpositions/Frequencies area can also interact with the “Rand. minimum” and “Rand. maximum” values you'll find elsewhere. These last two parameters output a new value based on the “Grains per sec.” control, which supports grain generation from 1 to 1,000 times per second. You can also set a high and low range for amplitude and for pan position (left and right channels only). Ten different window (smoothing) shapes provide additional subtle but noticeable timbral variations.

LowNorth RTGS-X 2.4 (Mac, $49)

RTGS-X is a robust program for creating granular textures and is well suited for live or studio use. Its Controllers Setup window (see Fig. 7) offers options for routing up to eight different control signals, which could be MIDI controllers or one of two different internal random generators, or two different Triggers (MIDI or a computer keystroke) to a variety of parameters (Grain Size, Grain Rate, and so on). You can record an entire session of slider moves and button presses using the Capture Stream option, then play back all movements at the original or any new speed you want. Pop-up help for every program component keeps your work session flowing, and a thorough HTML manual fills in any missing info you might need.

At the top of the RTGS-X interface are windows to control Grain Delay, Grain Length, and Buffer Position. The first two of these have sliders to adjust the percentage of a base value that you set in the Grains window and are especially handy in real-time performance. The Buffer Position also has a slider that represents where within a loaded sample file grains will be extracted. If you want to automate these parameters, you can create multisegment envelopes lasting up to 999 seconds and use them to control these or other program parameters. You can also map x and y mouse movements independently to three different parameters.

The Transposition slider controls grain pitch, and, as with the other parameters, you set a base value (in percent) and then apply some amount of random offset (in semitone increments; see Web Clip 9). There are also controls for panning and amplitude, with their associated random components.

RTGS-X limits its input to only the first 10 seconds of the source file (AIFF, WAV, AU, or NeXT format), and loads only the left channel of a stereo file. Other than that, there's nothing really missing from the program except a Windows version! (Granular-synthesis guru Barry Truax has noted that granulation typically destroys all sense of stereo separation in the original file.)

Stefan Smulovitz's Kenaxis 2.2 (Mac/Win, $145)

Tucked inside a very powerful looping and sampling interface are Kenaxis's two granulators, each of which uses the same sample but has the ability to process it in separate ways. For example, one might generate a high density of grains while moving backward through the source file at half speed, whereas the second plays back a version of the file stretched to several times its length but with the pitch intact (see Web Clip 10). You can use the Random File Impulse command to instruct Kenaxis to pick sample files randomly from a folder you designate, or drag-and-drop a new file manually onto the Granulator file window even while the program is playing back. Kenaxis supports only mono files (or the left channel of a stereo file) for granulation but outputs audio in stereo.