Plug in to Creativity

Plug-ins that process digital audio continue to crop up in a seemingly endless variety of formats and types-TDM, AudioSuite, VST, Premiere, real time,

Plug-ins that process digital audio continue to crop up in a seemingly endless variety of formats and types-TDM, AudioSuite, VST, Premiere, real time, non-real time, and so on. For me, one of the most important applications of these ubiquitous little programs is the creation of new sounds by transforming existing audio material.

I'd like to share some techniques I've used with certain plug-ins to produce interesting, unusual results. My emphasis will be on creative uses of existing plug-ins, which I hope will encourage you to experiment with them on your own. Keep in mind that you can use hardware devices to apply many of the techniques and ideas described here; you don't have to limit these suggestions to plug-ins alone.

Throughout this discussion, I'll mention particular plug-ins that are available in TDM, VST, AudioSuite, and Premiere formats. If you don't have a TDM system, you can obtain very similar sonic results with the other versions of the same plug-ins.

DRUM DECONSTRUCTIONYou can do many fun things with drums using plug-ins. For example, add some distinctiveness and crunch to live or sampled drum sounds by using Digidesign's D-Fi series of plug-ins (TDM, AudioSuite); these plug-ins let you distort, destroy, and generally lower the fidelity of individual drums or entire kits.

The Lo-Fi plug-in from the series is well suited for creating interesting overtones, distortion, and aliasing effects. If you're working with individual, isolated drum tracks, try applying it to the kick and snare, and experiment with low Anti-aliasing settings. The lower the setting, the more high-aliasing artifacts will be introduced, which can be quite effective on drums because of their metallic quality. In addition, try small amounts of distortion; low values can add some punch and "spread" to the sound of kicks and snares. Larger values tend to obscure the original sound completely and create a washy effect, which can be useful at times.

You can also apply these techniques to stereo drum loops or drum-kit recordings. You will probably have to adjust the amount of anti-aliasing to compensate for the increased complexity of a full drum kit, because the high-frequency content of cymbals and hi-hats might clash with the overtones created by the plug-in.

For more drastic distortion effects, you can use Recti-Fi, another part of the D-Fi suite (see Fig. 1). A range of different distortion effects can be created using the Prefilter and Postfilter controls, so experiment with these. Even if you end up with an excessive, ridiculously distorted result, you can regain clarity by using the Mix control to mix the original signal back in.

Something to keep in mind about this plug-in is that it isn't true stereo. When processing a stereo source with certain settings, you might hear obvious phase artifacts. This is not a bug; the program's designer left it that way because he thought it sounded interesting, and I agree with him. Experiment with different settings and you'll find some unusual results.

FILTERINGFiltering can be an incredibly potent effect with many different sources, from drums to vocals. For the following examples, I'll use GRM Tools' Band Pass filter (TDM, VST) and Opcode's fusion:Filter (Premiere, AudioSuite, DirectX).

Lowpass is probably the most widely used filtering type. Once again, drums give you a good place to start. If you want to achieve a basic tonal change, apply a lowpass filter to the entire drum kit, setting the Cutoff Frequency and Resonance to about 40 percent or less. As a result, this produces a muted effect that gradually becomes a more pronounced "note" as you increase the resonance.

For more animated effects, modulate the cutoff with a sine wave LFO for cyclic effects or an amplitude envelope for a filter that varies with the volume peaks in the drum track. Opcode's fusion:Filter includes some presets that do exactly this (the "Cool Drums" patches). These techniques also work well with percussion tracks and loops.

Of course, lowpass filtering has many other uses. On guitars and synthesizers, slowly swept lowpass filtering can give some tonal animation to repetitive parts. To start with, set Cutoff and Resonance to 50 percent with a medium (0.5 Hz) LFO modulation rate and medium mod depth. A sine wave is a good place to start for the LFO waveform, but be sure to try others as well-square, ramp, sawtooth, and even random waveforms can be useful in certain musical contexts.

Bandpass filtering is excellent for drastically deconstructing all sorts of musical sources. I have attained great results by applying it to drums, percussion, guitars, and vocals, but I encourage you to experiment with it on just about everything. You never know what you'll find.

GRM Tools' Band Pass Filter is a good-sounding, flexible filter plug-in that has a particularly musical sonic character, making it well suited for many applications. Perhaps the most obvious and immediate application is to make sounds "smaller." If you apply the Band Pass plug-in to virtually anything, the default setting makes the source material sound tiny, because the default uses a fairly narrow bandwidth with the center of a band in the upper midrange area (around 800 Hz). This can be a very effective tool as a special effect or to make a musical part fit better into a crowded mix. But thanks to the extremely precise (read "digital") nature of its design, this plug-in is capable of some specific, highly unusual effects beyond simple size reduction.

Try the following technique on pitched, continuous material, such as a sustained synthesizer texture. While the track is playing, drag the plug-in's control cursor along the rightmost edge of the black work area, from lower to upper right (see Fig. 2). In a continuous motion, keep going around the outer edge of this window, from the upper right corner to the upper left corner. You will hear a descending overtone sweep. The character of the GRM filter gives this sweep a distinctive quality that can prove very useful.

The Band Pass plug-in can also approximate the effect of a lowpass filter, creating dark, muted effects. Positioning the control cursor toward the middle left side of the work area puts you in the right "neighborhood" for this effect.

VOCODINGAlthough vocoding is not a new effect, it is a relatively recent arrival in the world of plug-ins. Here is a useful technique that works equally well with a conventional hardware vocoder or a plug-in, such as Prosoniq's Orange Vocoder (see Fig. 3) or Opcode's fusion: Vocode.

You can realize one of the most interesting vocoder effects by modulating a sustaining, shifting texture with rhythmic source material, such as a drum track or rhythm loop. To do so, use the rhythmic material as the modulator and the sustaining texture as the carrier. That produces a composite vocoded signal with the rhythmic pattern of the modulator superimposed on the harmonic information of the carrier. This effect is great for creating intriguing textural rhythm patterns, particularly if you mute the original modulator source. Try experimenting with a variety of carrier and modulator sources; you are likely to find some pleasant surprises.

Another idea is to process the vocoded signal with additional effects, such as delays, reverbs, filters, and so on. Vocoder sounds are complex, but they are also quite familiar, so it behooves you to add interest by applying more effects. Two general suggestions for this are swept filtering and rhythmic delays, but by all means try your own ideas here as well.

REVERBThere are techniques that can breathe new life into the all-too-familiar digital reverb effect. One good place to start is to place other effects just before the reverb input. It's surprising what that can accomplish; even a humble flanging effect (set to fairly high regeneration and a slow, wide sweep) placed before a reverb's input can bring out lovely overtones in the reverb itself. That can go a long way toward creating a surreal atmosphere.

On the other hand, placing effects after the reverb can be interesting as well. For example, try using GRM Tools' Doppler effect or WaveMechanics' excellent PitchBlender (see Fig. 4) or TimeBlender (highly recommended) across the reverb return. That produces stereo pan/volume sweeps of the reverb tail that can be far more effective than standard reverb decay. Keep in mind that it tends to work best with longer (more than 2-second) reverb times. In addition, try using a medium-fast tremolo effect with moderate depth across a reverb return. Arboretum's Tremolo works well for this application, and the results can be quite unusual, particularly if you modulate the tremolo rate over time.

PITCH CHANGEMany plug-ins and hardware devices perform high-quality pitch-shifting effects. However, these effects can go far beyond the standard pitch correction or simple transpositions for which they are most commonly used. Pitch-shifting effects have always shown great potential for creating sonic interest when used imaginatively. For example, listen to producer Tony Visconti's use of the first-generation Eventide Harmonizer to create powerful, innovative drum sounds on David Bowie's landmark Heroes.

Here are some suggestions to get you started. On slow, legato parts (guitar is an excellent candidate), shift the pitch up by one octave and delay it by a musically related value (such as dotted eighth notes) to bring out the musical line in an interesting way. This is especially effective if the pitch shifter output is sent to a reverb or spatial effect and mixed in subtly.

Shifting drums and percussion tracks up or down by a major third or so can create unusual sounds, particularly if the shifted part is blended in as a background "shading" effect. Be sure to set any delay times in the pitch shifter to 0. Using high regeneration settings while shifting the pitch up one octave with rhythmically relevant delay times can be great fun, particularly on light percussion sounds or staccato synth patches.

ROUTING AND COMBINATIONSOne way to get the most out of your effects plug-ins is to combine them to create more complex textures, rather like a guitarist's pedalboard. Very often, combining seemingly mundane or simple effects in the right way can produce unexpectedly potent results. For example, consider a phaser or flanger plug-in. These sounds are so familiar that they are a bit boring on their own. However, placing a spatial effect, such as GRM Tools' Doppler or even one of the D-Fi plug-ins, directly after it can transform these ho-hum effects into highly unusual hybrids.

Approaching plug-ins as you would a guitarist's pedalboard can be very effective. Many individual plug-ins might not sound spectacular on their own (much like stompboxes), but when they are judiciously combined in series, some interesting things can happen. There are many reasons for this, but it's often because one effect emphasizes certain characteristics of the previous effect while eliminating other characteristics, or because certain effects combine well, acting as components of a more complex composite sound.

Consider a filter placed after a distortion effect. Distortion creates overtones not found in the input signal, and filtering can bring out certain frequencies while eliminating others, so placing these two effects in series can actually change the perceived musical content of a sound or part. Try it for yourself, particularly on guitars and other harmonically strong material. You can get good results using practically any type of filter, from lowpass to bandpass/notch or even highpass.

You can also get a composite effect by using any swept effect (phasing, flanging, or swept filtering, for instance) followed by long delays with a substantial amount of regeneration. With many different types of source material, such as drums, guitar, and synthesizers, this simple combination can produce results that are sonically greater than the sum of their parts. The delays create a multiplying effect that increases the perceived complexity of the sweep. However, it doesn't have to end there. From this starting point, try adding other effects before the sweep (for example, distortion) or after the delay (for example, spatialization) to create even more complexity.

Real-time plug-in formats, such as TDM and VST, enable you to create complex signal routings, so take advantage of them. For instance, sending the same track to three aux sends, each connected to a different plug-in, can often produce great results. One combination that has worked well for me is reverb, delay, and swept filter, with a bit of the filter output routed through the delay, all applied to an atmospheric guitar part. This type of parallel connection lets you retain the clarity of individual effects and control their relative balance while blending in the original source track to taste.

When you run across a combination of parallel effects that you really like, it's always worth muting the original source track while retaining the sends to the effects. (Do this by making the sends prefader and muting the source's track. The "dry" signal will disappear, while the effects balance remains unaffected.) In general, I have found that some of the most interesting processed sounds happen when you monitor the effects returns in this way.

EXPERIMENTATION IS KEYPerhaps the most important concept I can communicate is experimentation. Some of the most interesting sounds come about when you are just playing around and trying what-if scenarios. There are no rules, and the worst that can happen is that you won't like the results. So don't be afraid to try things, even if they seem outlandish or weird on paper. New things don't happen if you stick to established processes and conventions; besides, you always have these to fall back on if all else fails, so why be boring?

There is a formidable amount of processing power available to musicians who use effects plug-ins today, and I'm sorry to say that it's largely underexplored. Get extreme; try combining wildly different effects or too many effects. Put the wrong effect on a track, or use too much of the right one.

I hope the suggestions and techniques presented here prove inspirational. If I get just one person to try just one new idea, then all the time and effort I spent putting this information together will not have been wasted. Good luck, and happy tweaking.

Peter Freeman is a bassist, composer, and producer living in New York. He has worked with artists Seal, Jon Hassell, L. Shankar, John Cale, Shawn Colvin, and Nile Rodgers, among others.