By Craig Anderton
Pads can add beautiful atmospherics to a recording, but if you’ve ever tried to loop a pad, you’re probably aware that it’s not an easy task. Any kind of discontinuity as the loop jumps back to the beginning interrupts the pad’s flow, creating anything from a jarring effect to a massive click or pop. Although there are sample editing programs that can loop these complex sounds, you may not realize that the tools needed to create perfect loops are available in just about any DAW.
First, an assumption: The pad will have some sort of interesting attack that you want to retain. As a result, you’ll want to the loop to occur sometime after that initial attack. As pads don’t have rhythmic components, it doesn’t really matter whether you repeat a two-, three-, or four-bar section of the pad following the attack (or even a longer loop, if you’re so inclined). For our example, we’ll take a four-bar pad and loop the last three bars.
1. Record a little more than four bars of the pad.
2. Enable snap on your DAW (a half or whole note snap works well).
Fig. 1: Note that the file has been split at measure 2; everything after the start of measure 5 has been discarded.
3. Split the pad audio clip at the start of measure 2. Now the first measure is a separate piece of audio. Also split the pad audio clip at the start of measure 5, and discard everything after the start of measure 5 (Fig. 1). Next, we’ll need to crossfade measure 1 with the last measure of the pad (the one starting at measure 4). If your DAW offers automatic crossfading, you should simply be able to drag-copy measure 1 on top of the last measure. Make sure you use equal power crossfading. If your DAW can do this, skip steps 5 and 6, then continue.
Fig. 2: A one-measure fade-out has been applied to the end of the file, and a one-measure fade-in to a copy of the first measure (placed temporarily after the end of the file).
4. If your DAW doesn’t do automatic crossfading, copy measure 1. Use a convex fade-in curve for the copied measure 1, and a convex fade-out curve that extends from the start of measure 4 to its end (Fig. 2).
Fig. 3: The two areas with the fades have been layered to apply a crossfade.
5. Next, layer the two sections together (Fig. 3) to create a crossfade.
At this point, you have several options. If you want to create a loop out of the last three measures, bounce measures 2, 3, and 4 to a separate clip. This will loop perfectly at the host’s tempo. If you want it to loop at other tempos, or in other keys, you can either apply time-stretching DSP, or create an “Acidized” file with metadata that tells the file how to stretch (Sony Acid or Cakewalk Sonar can do this). Note that trying to stretch pads using ReCycle to create a REX format file won’t work very well; REX files work best for percussive loops.
If you want to use the attack too, it’s still available as the single measure we split off in step 3. Simply paste it in front of the loop, and you’ll hear the attack followed by the loop. Extend the loop for as long as you’d like.
Yet another option is if you want to use the loop in a traditional sampler, either software or hardware. In this case, you want the audio (including the attack) to start playing when you play a key or trigger a note-on, then as the note sustains, you want it to loop. To do this:
1. Bounce all four measures to a single audio file.
2. Use the DAW’s time ruler to locate the precise start of measure 2, using either samples or milliseconds (whichever format your sampler uses).
3. Import the audio file into your sampler.
4. Set the loop end to the end of the file. Set the loop start to the location you determined in Step 2.
5. Play the sampler. You may need to jog the sample start or end point a bit to get a perfect loop, but you should be able to obtain a loop with no glitches or pops.
Now you’ve transformed your pad into a loop you can “roll out” in a DAW track to provide a background, or load into a sampler. And it will loop perfectly!
Craig Anderton is Editor Emeritus of Harmony Central. He has played on, mixed, or produced over 20 major label releases (as well as mastered over a hundred tracks for various musicians), and written over a thousand articles for magazines like Guitar Player, Keyboard, Sound on Sound (UK), and Sound + Recording (Germany). He has also lectured on technology and the arts in 38 states, 10 countries, and three languages.