NoTAM's DSP 1.0 ($27) is a remarkably inexpensiveCD-ROM designed for teaching basic principles of the physics ofsound, synthesis, and signal processing while offering serioussound-design and mixing tools for professionals and amateurs alike.Originally intended for use in Norwegian public schools, the discincludes a helpful beginner's tutorial with sound examples forillustrating concepts and techniques.
DSP is a standalone Windows application that installson your PC, but you must have the CD in your drive to run it. Theprogram consists of integrated synthesis and signal-processingtools for generating and modifying mono WAV files and also hasrecording capabilities. In the Mixer window, you assemble filesinto Projects that contain as many as five mono tracks. You canedit the volume and pan settings for each track individually usinggraphic envelopes prior to mixing down to stereo 16-bit WAVoutput.
In keeping with the program's budget-conscious nature,DSP should work with any standard Windows audio hardware.Although the printed documentation says that the program loads onlymono files that are less than ten seconds, I recorded and loadedsignificantly longer files. The mono limitation, however, makesDSP unsuitable for working with stereo submixes.
Power and Convenience
DSP's main recording, editing, and synthesis functionsare conveniently located within submenus of the Sound menu. Thereyou have access to several synthesis techniques including simpleFM, dual-formant buzz, plucked-string physical modeling, awhite-noise generator, and 8-partial additive synthesis. Using theonscreen Record and Play buttons to record a sound from yourcomputer's microphone or line input is ridiculously easy. However,you can't adjust input levels from within the program; you must useyour system mixer for that. You can have only one file open at atime in the main editing window, so there's no way to cut, copy, orpaste between files.
The program provides tools for fading and adjusting theamplitude of selected ranges, and navigation tools includeHorizontal Zoom and Fit Selection Within Window. (According to themanufacturer, a vertical-zoom capability was omitted to limitwindow clutter and to simplify program operation.) Throughout theprogram, submenus feature a uniform interface with color-codedbreakpoint envelopes and sliders available for most parameters. Iwish it had precise displays of parameter and timeline values, butfor teaching concepts, simplicity is a compelling virtue.
Sonic Food Processing
The Distortion submenu contains various tools for modifyingsounds: Granular Synthesis, Time Stretching, Forward/ReversePlayback (scratch), Spectral Sieve, Spectrum Shift, and Random-notePlayback. I found the Spectral Sieve and Spectrum Shift features tobe especially unusual but musically useful. The filteringcapabilities of the Spectral Sieve are well suited for homing in onvarying degrees of the most significant spectral components,letting you create a wide range of sonic variants for a givensound. The Spectrum Shift tool adds or subtracts a fixed frequencyfrom each of 40 analyzed partials, thus transforming harmonicspectra into wildly dissonant collections of inharmonic partials,an effect that works well on the spoken word.
The Effects submenu offers the standard fare of reverb, delay,and chorus, as well as a multimode filter, ring modulator, andharmonizer. Unlike most hardware delay units, DSP's delayhas breakpoint envelopes for delay time and feedback amount, aswell as wet and dry mix parameters; creating cool Doppler effectsis a snap. In addition to the built-in reverb, the program providesa bonus utility for simulating various rooms. With that utility youcan use a 3-D graphic to modify the placement of mic and sourcewithin a user-defined room size and shape.
NoTAM provides a handy Web site for downloading additional soundsamples and exchanging music samples produced using the program. Anessential FAQ section offers answers to questions about programfeatures that are not thoroughly documented in the CD-ROM or theprogram booklet.
DSP has a handful of annoying omissions, including theabsence of undo-editing and save-as features, awkwardplayback-range controls, and inconsistent and sometimes sketchydocumentation. Aside from those drawbacks, DSP is simpleto operate and provides considerable power to anyone interested inlearning the basics of synthesis and signal processing whilecreating real pieces of music.