REX Files
Nov 1, 2001 12:00 PM, By Costa Kotselas
REX files are among the most useful tools for musicians, producers, and remixers who make tempo-based music. But even though this technology has existed for several years, REX (ReCycle export) files are still something of a mystery to most people, who think that you need to have ReCycle to use them. Actually, ReCycle (from Propellerhead) is necessary only for converting an audio file to a REX file. Once an audio file has been ReCycled, or REX'd, it can be used in a Cubase audio track without ReCycle.
Many CD-ROMs containing hundreds of REX files are available, so all you have to do is simply import or drag and drop the files into your audio tracks and hit Play. Once they are in your audio tracks, you can change tempos in Cubase and the loops will play back at the selected tempo. This allows you to layer several different loops that may originally have been recorded at different tempos to play back at the tempo you want. Now you can freely work with a variety of loops at any tempo you like. And you don't need to worry about time stretching, which can alter the original loop's sound quality, or experiencing a pitch change as the tempo changes, which is what happens when you work with a sampler. Besides simple playback, you can process and manipulate REX files in ways that are difficult to achieve with ordinary loops.
A BRIEF HISTORY OF LOOPS AND TEMPO
Using drum loops is a great way to create impressive drum tracks quickly. This method saves time because you don't have to program everything from scratch. A wide variety of sample CD-ROMs, audio CDs, and computer-format CDs with WAV and AIFF files offers a huge selection of styles and sounds that you can load into your sampler or computer. But the biggest problem with triggering drum loops with samplers is that if you change the tempo, the pitch changes as well. Samplers change pitch by slowing things down or speeding things up, so as you play keys up and down your keyboard, you also have to deal with the bpm changing in increments of ±6 bpm for each key. That makes it difficult to get the exact tempo you want without having to get into the sampler and fine-tune the loop to the bpm you want. Samplers are also problematic in that the amount of RAM you have in your sampler limits how many loops you can have loaded at one time, and you have to resave any changes you have made to a hard disk.
Now that most MIDI sequencers incorporate audio recording, you can load drum loops into your audio tracks from WAV or AIFF CDs, which is a bit more convenient, but you are faced with a similar problem of not being able to change the tempo easily. With digital audio, you have to do a time correction whenever you want a new tempo, which affects the original loop's audio quality and can disrupt your creative flow while working on music. There are many other drawbacks to using sampled drum loops in both samplers and computers. Often the loops are not exactly what you want. For example, you may like everything about a loop except for the snare, or the loop can have a great groove but terrible drum sounds, or it can have great sounds but a stiff feel, and so on. REX files give you the ability and flexibility to play back loops at different tempos without altering the pitch, and offer you many powerful possibilities for creating drum loops that sound exactly the way you want with a minimum amount of effort.
IMPORTING REX FILES AND CHANGING TEMPOS
Before you can begin, you need Steinberg's Cubase VST. Then download the ReCycle REX files at the end of this article onto your hard drive so that you can follow along. Start Cubase VST, select audio track 1, and set the left locator to the beginning of the song. Then go to the File menu and select Import ReCycle File. Locate the ReCycle REX files on your hard disk and open the first file, 0111.01_dla.rex. Cubase will ask you where you want the REX file to go. For the time being, choose your desktop because Cubase will convert it to a WAV or AIFF file. In the future, be sure to put the REX file into the folder of the song that you are working on.
The REX file will appear as a new part, starting at the left locator of the selected track. Move the right locator to the end of the part, and make sure that Cycle is set to On. Hit Play in the transport bar and listen to the loop. While the loop is playing, double-click on Tempo in the transport bar and enter different values using the numeric keypad (hit Enter on the numeric keypad each time). Try different values — 100, 120, 130, 135, 136, and so on — without ever stopping playback. You'll notice that the loop speeds up or slows down each time. Select track 2 and import the next REX file, 0111.02_cook.rex. Note that the loops play back at the same tempo even if their original tempos were totally different. Next, select track 3 and import the third REX file, 0111.03_vince.rex. This is a synth bass part — REX isn't just for drum loops. If you want to load more REX files, you can drag and drop them into your audio tracks from your computer's folders. The nice thing about importing REX files is that you have the option of auditioning them before bringing them in to your song.
TEMPO TANTRUM
How does Cubase change a REX file's tempo so easily? Double-click on any of the REX file parts to see what is going on inside the part (see Fig. 1). Notice that the drum loop has been cut up into individual slices, or pieces. When you enter a different tempo in Cubase, the loop will speed up or slow down the rate that it plays across each track in much the same way MIDI notes work. If you were to look at any single WAV or AIFF audio file that is a drum loop, it would be one continuous piece of audio, so no matter what tempo you put into Cubase, the loop plays back at the same speed — that's how audio works. Time stretching or time compressing alters the sound quality of the original audio file and is time-consuming. What makes REX files better is that no time stretching or compressing is going on. For most situations, this is a quick and easy way to put together different drum loops and music loops to assemble songs instantly.
PAN AND EQ
To get a little more variety from these tracks, you can go to the VST mixer and pan each individual track to spread the sounds out around the stereo field. For this example, pan channel 1 hard left and channel 2 hard right. You should find that your drum loops sound more interesting coming from different areas. You can also add a little EQ to each channel and process them with VST effects such as reverb or delay.
CUT, COPY, PASTE, AND REPLACE
Working this way is like having Sonic Foundry's Acid inside Cubase's audio editor. REX, however, goes much further than that, because you can move around or copy individual slices of the loop or components of the loop. If you've ever wanted to create those stuttering, chopped-up beats that you've heard on records by BT or drum 'n' bass artists, this is a great way to do it. Working with these little snippets of audio is similar to working with MIDI notes. You can click on the individual pieces of audio to cut, copy, paste, pick up, move around, and rearrange the components of the original loop. Try clicking on the first piece of audio, which is a kick drum. Select it, then hold down Option on a Mac or Control on a PC and drag it over to the right a bit to make a copy. Do this several times until you get some cool fills, rolls, or stuttering effects. The quantize value you select determines where the piece snaps to the grid. This means that if you use 16th notes, Cubase will let you drop the pieces only to the nearest 16th note, and if you use 32nd notes, it will let you drop the pieces only to the nearest 32nd note. Experiment with both, and 64th notes as well, to hear the different kinds of fills you can create. You can even move pieces of audio across several different tracks to pan them and process them through the VST EQ and plug-in effects separately. For example, you could move all the snares to another track and route that channel's effects send to a reverb, so that only the loop's snares get reverb while the rest of the loop stays dry.
Let's say you like everything about a loop except for the snare. Just delete or mute it and replace it with any other sound you like. It doesn't matter if you use a piece of another REX file or any other audio file you have on your hard drive — you can replace it with any sound you want.
GROOVE THE REX
Each piece of audio has a Q-Point, which means that each piece will snap to the closest 16th note or 32nd note on the grid, depending on the quantize value that you have selected. You can now quantize or groove quantize the loops to alter each one's original feel. That way, you can make the loop fit into your song or the style of your song by hard quantizing, swinging, and so on. Besides using Cubase's Groove Control to quantize, you can also use the Match Quantize tool to quantize MIDI parts to audio parts or even use another REX audio part to match quantize that part's audio feel.
STEREO REX
AMG is the first sample CD company to take advantage of the ReCycle 2.0 stereo .rx2 file format. Its Phil Gould on Drums CD-ROM contains hundreds of stereo REX files that are ready to go. To use stereo files, just be sure to make a stereo track in Cubase before importing them.
BETTER THAN STEREO WITH THE ANY CHANNEL
To get even more variety from one loop, split it across several tracks automatically by using the Any channel. Go to the File menu and choose New Arrangement. Create a new audio track, but this time choose Any in the channel column where the channel number is indicated. Next, go to the File menu, select Import ReCycle, and choose the downloadable 0111.04_mayhem.rex. A dialog box will appear that says, “Divide the Recycle File into Channels.” Choose 3 for now). Double-click on the part and look inside, where you will see that the loop has been split across three tracks thanks to the Any channel. Hit Play and go to your VST mixer to see how the one loop is playing back on channels 1, 2, and 3. Next, pan mixer channel 1 hard left and channel 3 hard right. Is this starting to make sense? You should hear different parts of the loop playing around the stereo field. Don't be shy — you can now click on solos, mutes, pans, EQs, effects sends, and even effects parameters to squeeze more variety out of that tired old loop. Try sending channel 1 to a chorus effect, channel 2 to a delay, and channel 3 to a reverb. Solo one channel and sweep the EQ. Click on an effects parameter and play it in real time. Then try clicking on individual slices and copy them around inside the part to create some rolls and fills — the possibilities are endless. It is best to arrange the EQ and effects sends the way they are in the screen shot in the magazine so you can play the mixer like an instrument. If you want to record your movements, just click on Write in the VST mixer, and Cubase will record your moves with its automation feature. If you want to bring in more REX files and split them across different channels automatically, click on Starting with Channel x and then enter 4 for channel number because you already have some sounds on channels 1, 2, and 3.
This method can bring new life to static drum loops. You can also bring new life to a whole song: instead of repeating the same loop over and over again, which can sound stale after a few minutes, you can make subtle changes to loops over time. Copy the REX part out a few times, and then go into each consecutive part and move or copy some of the slices around. That way, each new loop will sound different and evolve throughout the song.
ISOLATING INDIVIDUAL DRUM SOUNDS
Many producers and remixers prefer to put all the kicks on one track, all the snares on another, and all the hi-hats on another so that they can EQ and process these sounds separately. There is no way to do this automatically, but you can audition each slice with the audition tool and then place each type of sound onto a different track. To do this, make sure the channel number is set to Any and then hold down Shift while you move one piece to another track. This prevents you from moving it to the left or right, which would put the sound out of its original placement in time. Once you have moved the different drum sounds to their own individual tracks, you can go into your VST mixer and EQ and process them separately. EQ the kick with a bass boost, add a little reverb to the snare, and dial in some high-end EQ to make the hi-hats sizzle.
REX YOUR OWN
If you have some of your own audio — whether drum loops, bass parts, or loops from any sample CD with WAV or AIFF files — you can use ReCycle to make your own REX files. If you already own ReCycle 1.7 and you want stereo REX files, you can update to ReCycle 2.0 for $49.99 from the Propellerhead Web site (www.propellerheads.se). Once you have sliced up the loop of your choice in ReCycle (don't forget to enter the number of bars so it automatically calculates the tempo), you can save it as a REX file. Then go to Cubase and import a REX file right into your VST audio track.
By using REX files in Cubase, you have a huge choice of great source-material options for putting together some really cool music simply by dragging and dropping files. This is a quick and easy way to get your songs started. The key to making truly creative and unique music lies in the ability to cut, copy, move around, EQ, and process your drum slices and loops differently. By tweaking sounds to your own liking, you can create music that sounds different from anything else out there, even though you may have started with sounds that everyone else has access to. With practice, you can create impressive drum tracks that sound like you programmed or recorded them yourself. With just a little effort, you should be able to create songs that will have people asking, “How did you do that?”
Costa Kotselas is a writer, a producer, and an artist, as well as a consultant to Steinberg and many top Hollywood composers. He has had songs placed in TV shows like Beverly Hills 90210 and Charmed and in various independent films. Check out his music online at www.entropyofchaos.com.
Here are the links to the REX files in this article:
1) dla
2) cook
3) vince
4) mayhem
REX ADDICT: A GUIDE TO REX CD-ROMS
A huge variety of dedicated REX CD-ROMs containing hundreds of loops already cut up by ReCycle are available and ready for use in your VST audio tracks. The two main producers of REX CDs are AMG and Sounds Good, but many other companies also produce REX content.
AMG
Some of the world's best-selling audio-sampling CDs are available from AMG in REX format. Many of its releases feature real drummers playing acoustic kits that are professionally processed and recorded. AMG also offers a good variety of electronic and ethnic drum loops, as well as musical loops like guitar and synth riffs. REX-format titles offered by AMG include Dance Diffusion, Beatz Diffusion, Pop Diffusion, Vince Clarke's Lucky Bastard, Norman Cook aka Fatboy Slim's Skip to My Loops, 160dB: The Drum and Bass Interface, Terminalhead's Underfire, Coldcut's Kleptomania, Gota Yashiki's The Funky Monk, vols. 1 and 2, Rhythm of Life, and Phil Gould on Drums.
Pocket Fuel
RADS, the newest series of REX CDs from Pocket Fuel, features a variety of performances by real drummers processed with effects. Current releases include Acoustic Rock Drum Loops, Acoustic HipHop Drum Loops, and Techno Rhythm and Loops.
Sounds Good and Steinberg: Sounds & Cycles
These are basically classic drum-machine sounds programmed into beats, REX'd, and ready to go. Six different titles are currently available, catering to a whole range of musical tastes: The Electro Age, Drum 'n' Bass X-Citers, On a Latin Tip, Chemical Big Beats, Cold Fusion Technologic, and Hip Hop Beats and Treats.
Wizoo's VST Drum Sessions
Wizoo has taken a different approach to REX files. Instead of providing entire drum loops, it offers drum tracks that have been separated by drum types, with kicks, snares, hi-hats, and toms split out onto separate tracks and then organized into complete songs with intros, verses, choruses, and so on. Titles include Heavy Rock, Big Beats, Soul Dance, Pop, Straight Rock, and Rhythm and Blues.
OTHER REX HOST PROGRAMS
Propellerhead's Reason features a dedicated REX player, which allows you to trigger the individual slices from a MIDI keyboard and lets you change the pitch and pan of each slice. Emagic's Logic 5.0, scheduled for release this fall, also promises to support the REX format.
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