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electronic MUSICIAN


By Peter Freeman | August 1, 2000

Having distinguished themselves with their previous work for Eventide on the DSP4000 and the ModFactory upgrade for the H3000, the folks at New Jersey's Wave Mechanics have considerable experience in making powerful DSP audio software. Now, with the SoundBlender plug-in package, the company has turned its attention to the TDM platform.

SoundBlender is actually a pair of TDM plug-ins: PitchBlender and TimeBlender. PitchBlender is a 2- channel effects processor that combines pitch- shifting, delay, filtering, panning, and modulation. TimeBlender is nearly identical to its counterpart, except that it offers reverse pitch-shifters in place of the standard ones. (A reverse pitch-shifter samples snippets of sound and plays each one backward; the backward samples can then be processed with filters, feedback, and modulation.)

SoundBlender requires a Digidesign Pro Tools system with at least one "classic" PCI DSP Farm card or 24 Mix card (it won't even run on a NuBus TDM system). Both SoundBlender plug-ins offer extensive processing capabilities that require a great deal of computational horsepower. It's therefore not surprising that each instantiation of a SoundBlender plug-in uses an entire DSP chip on either type of Pro Tools card. Nevertheless, it's worth the processing cost.

I reviewed the stand-alone version of SoundBlender, which is currently available only for the Mac. Wave Mechanics also offers a Mac and Windows NT version, but only as part of the pricier UltraTools plug-in package ($895).

PANELS AND PARAMETERSSoundBlender's plug-ins employ a deceptively simple layout that belies their impressive capabilities for creatively processing sounds. The SoundBlender window has five main areas: Levels, Bpm, Trig, Parameters Control Panel, and Modulation. Along the top of the window, you'll find the Pro Tools Inserts/Sends Editor panel, which includes a drop-down menu for selecting presets. Because PitchBlender and TimeBlender are similar in design, I'll focus primarily on PitchBlender for the following descriptions and point out differences between the two where applicable.

The Levels controls consist of simple Input and Output sliders with corresponding stereo metering. The Bpm area is used for adjusting SoundBlender's tempo source (via a pop-up menu) and for setting its internal tempo with a pop-up slider or from the keyboard. The possible tempo sources are None (internal), Master Trigger, SideChain, and Input. The Master Trigger mode derives a tempo from PitchBlender's Master Trigger (explained shortly); SideChain uses the PitchBlender SideChain input (which can be any available TDM input or output); and Input derives the tempo from the audio signal that is actually passing through the plug-in.

The Trig area features a pop-up menu for selecting any of eight trigger sources, which include None (internal), SideChain, Input, Output 1, Output 2, and Mod Outputs 1, 2, and 3. A small fader is provided for setting the trigger threshold with the mouse.

The Parameters Control Panel area houses PitchBlender's adjustable effects parameters, which are grouped into seven "pages": Main, Pitch, Pitch Mapper, Delay, Filter, Signal Flow, and Expert. Each page has six parameter sliders, which you can drag with the mouse. You can also enter specific settings by simply selecting a parameter's value and typing in a new number.

TURNING PAGESThe Main page (see Fig. 1) lets you control the Wet/Dry Mix, Feedback, Master Pitch, Master Delay, Mod Depth, and Mod Rate parameters. These are global settings, but they are dependent on other parameter settings in PitchBlender.

As you might expect, the Pitch page provides control over the plug-in's pitch parameters, which include Shift 1 and 2, Pan Shift 1 and 2, and Level 1 and 2. The available pitch transposition range extends from - 2,400 to +2,400 cents (plus minus2 octaves).

The Pitch Mapper page allows you to map specific harmony pitches to incoming notes for generating "intelligent" harmonization and arpeggiation. The arpeggiation function is particularly interesting because it's controlled entirely by PitchBlender's modulation parameters. That makes possible some very unusual patterns. For example, a sawtooth wave used as the modulator creates the standard up/down arpeggio, but a more unusual waveform can yield much less predictable results.

The Pitch Mapper offers a number of non-equal-tempered scales for creating non-Western harmonies from a conventional (equal-tempered) input. When no modulation is present, the Pitch Mapper maps the current input pitch to the nearest note in the selected scale. Chordal arpeggios are also possible with the Pitch Mapper when you use a modulation source. Among the available preset chords are 6th, 7th, and sus4 chords, as well as major, minor, augmented, and diminished triads.

One particularly nice feature of the Pitch Mapper page is the inclusion of Attack and Decay parameters to govern the upward and downward speed of pitch variation from the generated harmonies-similar to portamento. This can be quite expressive if used subtly.

The Delay page controls the amount by which PitchBlender's two independent delay lines delay the input signal. Delay times can be expressed in milliseconds or beats (relative to the current tempo). Panning and Level controls are included for both delay lines, and delay times of up to 700 ms per side are possible.

PitchBlender has two independent multimode filters, each of which can be set to Lowpass, Peak BPF (bandpass filter), Norm BPF, Highpass, or Notch. Both have separate cutoff and Q controls (to control the shape of the filter). The frequency range of the filters spans from 40 Hz to 20 kHz.

The Signal Flow page controls the input level for each channel. It also controls the global Feedback balance between both channels, the Feedback Mix (actually cross-feedback between the channels), and the routing order of the effect blocks in PitchBlender.

These routing choices (see Fig. 2) are governed by two sliders called Filter and Algorithm. Filter determines where in the signal chain the PitchBlender filters appear. The choices are Pre-EFX (filters after input), Pre-EFX+ (the same, but with the filter outputs summed), Post-Pitch (filters at the output of the pitch-shifters, before panning and mixing), Post-Delay (filters at the delay line outputs), Post-EFX (filters at the end of the signal chain), and Loop (filters in a feedback loop).

The Algorithm slider lets you choose one of four global effects algorithms: Loop (creates delayed regenerative effects), Tapped (only the delayed signal is regenerated), Series (the same as Tapped, but pitch level and panning control the input to the delay lines), and Parallel (allows pitch-shifters and delay lines to be used independently).

The Expert page allows you to choose whether delay times are expressed in milliseconds or beats and also provides several parameters for optimizing the audio processing. You can set the minimum and maximum frequencies for the pitch-shifters to optimize the shift quality. The Shift Delay parameter lets you strike a balance between the fastest possible response of the pitch-shift engine and the best shift quality. The SoftClip function serves as a cushion against the digital clipping that occurs when input signal levels get too high. Instead of allowing the signal to distort right away, SoftClip causes a more tolerable "analoglike" distortion. Needless to say, this function is best left on.

MODULATION MADNESSThe Modulation Control Panel area is where things really start to get interesting. PitchBlender's many modulation possibilities aren't obvious; its numerous options are hidden away in menus. Once you peruse the list of sources and destinations, however, you'll be amazed by the program's staggering capabilities.

PitchBlender provides three simultaneous modulation generators for which you can select any of 16 modulation types: Sine, Square, and Triangle Oscillator; Random Numbers; Square, Ramp, Triangle, and Random Triggered; Square and Ramp Toggled; Env. Detector; Gate; Random Square and Linear; Always On; and Always Off. These can be sent to any of the following destinations: Pitch, Pitch Map, Delay, Filter Frequency, Pitch Pan, Delay Pan, Pitch Level, Delay Level, Input Level, Feedback, Mod Rate, or Levels 1, 2, and 3.

In addition to the raw flexibility provided by these extensive routing possibilities, PitchBlender's modulation parameters allow for further modification of the signal. For example, the Sync Mode options and Phase Offset parameter for the LFOs (LFO 2 and 3 can be free-run or synched to 1) provide added control over the final result; so do the Attack and Decay adjustments, which smooth out abrupt modulation changes. A handy Beats/Hertz switch lets you change the display units relative to the master Bpm setting.

You control modulation with a mixer and parameters found in the lower third of the PitchBlender window. The layout is largely self-explanatory (with the exception of the pop-up menus, which aren't readily apparent) and is quite simple to navigate. Just choose a modulation source, a destination, and a modulation amount (positive or negative) for one or all of the three modulation generators, and you're off and running. The only problem is that with complex modulation setups, keeping track of what is modulating what may be difficult. That's because you can see only one set of routings for the three sources at any given time. This is one limitation of working within a plug-in format: you get less onscreen real estate than you would in a stand-alone application. Nevertheless, the creative possibilities are well worth the inconvenience.

SMOOTH OPERATORFrom the moment I began using PitchBlender, it proved to be a highly effective tool. Although a great many presets are included with the SoundBlender package, I got the best results by starting from scratch and creating presets for specific situations as they arose. Once I played around and became familiar with the modulation routings, generating interesting effects was easy. Among the patches that I created were some slowly evolving, filtered stereo delays; bizarre, atonal, pitched delays; and a very long, high-feedback panning echo. I also used PitchBlender for straight pitch-change effects, which were excellent. In fact, they (not surprisingly) matched those of my Eventide DSP4000 in quality.

The multimode filters offer some particularly interesting possibilities, especially when used with the delays and pitch shifters. Although on close scrutiny the filters exhibit a noticeably digital sheen, they were musical enough to be useful in almost any context that I devised for them. It's possible to crank up the resonance and get fairly convincing "oscillation" out of them (one of my usual litmus tests for filter quality); this works very nicely with the delays.

At the risk of overstating the case, it's remarkable how powerful PitchBlender's modulation possibilities actually are. This becomes especially evident when you start playing around with triggered modulation from either the sidechain or main audio input. For example, LFOs that are continuously retriggered from an external rhythmic source (via the sidechain) can be used to modulate filter or pitch parameters. I also like the Attack and Decay parameters in the Modulation section; they add another layer of expressiveness that helps create unusual effects (such as using slow attack times to fade in modulations).

BACK IN TIMEAs I mentioned earlier, the main difference between PitchBlender and TimeBlender is TimeBlender's substitution of reverse pitch-shifters for the "normal" shifters (see Fig. 3). The reverse shifters are laid out as follows: In addition to Shift and Delay controls for each side, TimeBlender also features Length sliders, which determine the length of the "sample" that the reverse shifter takes of the incoming signal. It uses this sample for creating the reverse effect. Length values up to 900 ms are possible, along with a plus minus 1-octave pitch-shift range and up to 1,000 ms of delay time. In all other respects, TimeBlender is functionally identical to PitchBlender.

In actual use, the reverse shifters proved to be substantially different from the normal ones. I found that re- creating the same patch in TimeBlender that I had previously created in PitchBlender often yielded dramatically different results, simply by virtue of the reverse shifters' different sound and response. Combining long Length settings with long delay times also produced quite interesting sounds, especially with slow LFO filter modulation.

At a certain point, I questioned the reasoning behind producing an entirely separate plug-in (TimeBlender) that has only one real difference, rather than simply adding a normal/reverse pitch-selector switch to PitchBlender. According to Wave Mechanics, programming-related issues governed the two-plug-in decision, and the company is still considering the possibility of integrating them.

SPECIAL BLENDPitchBlender and TimeBlender are two of the best-sounding and most intelligently designed TDM plug-ins available. Once learned, their Modulation sections provide a rich palette of creative possibilities for those seeking to generate unusual effects. Of course, you can produce conventional pitch shifts, delays, and filtered sounds, but the modulation routings really put these plug-ins in a class of their own.

Unlike DUY's DSPider or the Eventide DSP4000, the SoundBlender package makes no attempt to be a low-level DSP creation environment-and that's a smart move. The engineers at Wave Mechanics clearly understand the limitations of the plug-in framework and have developed a program that strikes an excellent balance between ease of use and programming flexibility.

I only wish that the plug-ins offered more onscreen space to display, in one view, the state of all the modulation routings. Indeed, Wave Mechanics' Ken Bogdanowicz says that an alternate version of SoundBlender is being considered; it would have a much larger window area to display more parameters simultaneously. MIDI control is also under discussion.

In my conversation with Wave Mechanics reps, they also revealed the impending release of SoundBlender Plus, which may be available by the time you read this. The Plus upgrade offers an "extended" PitchBlender with distortion, ring modulation, downsampling, and bit-quantization capabilities. It also boasts two more filters and a new algorithm called SpaceBlender that has six delay lines, each with its own filter and distortion. This is exciting news, and I look forward to checking out these additions as soon as they're released.

In summary, the SoundBlender package is an essential tool for TDM users who are interested in creating powerful new effects. I highly recommend it.

Peter Freeman is a bassist, composer, sound designer, and producer in New York. He has worked with Seal, Jon Hassell, John Cale, Nile Rodgers, Shawn Colvin, and other artists.

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