oreilly.com: Inside FL Studio—Euro Techno’s Secret Weapon, Part 1

Image-Line FL Studio (the Windows music program formerly known as Fruityloops) is so packed with features, it's doubtful anyone but the programmers knows everything it will do. Almost every time I use it, I notice a little button or menu item that I swear wasn't there before. And not infrequently, a seemingly innocuous little button opens up a window with several cool features.

So even a two-part tutorial isn't going to tell you everything you can do with FL Studio. What I've tried to do in this and the next installment is shed light on some of the more obscure corners of the software, while also bringing newcomers up to speed on a few things that are important, but perhaps not obvious at first glance.

In Part 1 we'll cover audio and synthesis topics: signal routing in the mixer, basic audio recording, and programming the Sytrus FM synth. Part 2 will explore the precomputed effects in the Sampler's Channel Settings window, sequencing external MIDI hardware, and using controller data. You can download a demo version of the program on the FL Studio site, and buy it for as little as $49. You can also add a variety of plugins.

FL Studio began life as a modest, pattern-oriented sequencer with a few built-in sound generators. Its newer, more pro-oriented features have been grafted onto that base, which results in some odd design choices. For instance, audio tracks can't be muted in the track display at the bottom of the Playlist window. Instead, they're muted in the Step Sequencer. If you've never used a conventional DAW (digital audio workstation) sequencer, this type of thing may not bother you, but you need to understand that FL can be a bit quirky.

Signal Routing in the Mixer

Most FL Studio users quickly discover how to send the signals from different generators to different mixer channels using the FX parameter in the upper right-hand corner of each generator's Channel Settings window. With 64 mixer channels available, giving each Generator its own channel is not a problem. You'll most likely run out of computer CPU cycles long before you run out of mixer channels.

First, notice the OUT box at the bottom of the mixer (see Figure 1). Normally, this box is set to “Master” for the individual channels, while the Master channel's OUT is set to send the final mix to your soundcard. But here's a scenario in which you may want a different output routing:

Let's say you want to run several drums through the same compressor, while adding reverb to some of the drums but not others. Instead of routing each drum sampler to its own mixer channel (though you could do it that way), route the drums that need reverb to FX 1 and those that don't need reverb to FX 2. Put the reverb effect on the FX 1 mixer channel and the compressor on FX 2. Finally, switch the OUT of FX 1 to FX 2. This will send the post-reverb sound from FX 1 through the compressor, after which the entire percussion mix will be sent to the Master channel.

FL Studio provides four global send busses with their own insert effects. These busses will most often be used for a reverb, chorus, flanger, or delay that you want to apply globally or to several instruments. The send knobs at the right edge of the mixer control surface (these knobs can be automated, by the way) take care of basic send needs by sending the output of the mixer channel to the send bus. As with most send busses, this signal is in addition to the main output for the channel.

But what if you're applying a special reverb to a synth sound in its own FX channel, and you want to send the dry sound of the synth to the send bus before the reverb is added? This type of routing is especially useful when the send effect is chorus or flanging, because chorusing or flanging a reverb decay tends to sound quite artificial. (Then again, that may be the sound you're after.)

To place the chorus before the reverb, first left-click on an empty FX slot for the mixer channel and select Fruity Send. If necessary, left-click again and select “Move Up.” This moves the Send “effect” up above the reverb in the signal path. Finally, in the Send Edit window (see Figure 2), choose the send channel where the chorus or flanger is located. Now the dry signal will be sent to the chorus, after which reverb will be added within the FX channel itself.

Figure 2. The Send Edit window (left) is simplicity itself, but even here there are possibilities to explore. By automating the two VOL knobs, you can send a given signal alternately through two separate effects chains—one in the mixer FX channel and the other in the send channel. If you'd rather listen to this window than look at it, check out this MP3 (484KB), which I created by using the Send Edit graphic as source material for additive synthesis in FL's mysterious Beep•Map generator (right).

Each mixer channel has its own three-band EQ, which appears next to the channel fader and meters in the lower right corner of the mixer window. Sculpting each sound with its own EQ can make your mix seem less cluttered by removing frequencies that are fighting with one another. The general rule for mixing is to use EQ to cut frequencies rather than to boost them. Adding a sharp peak to a percussive sound with midrange EQ can add to the punch and help the drum cut through a busy mix, but with many of the FL Generators you can accomplish the same thing with a resonant filter in the generator itself. The filter will give you more control over the tone; for instance, the cutoff frequency can be changed from note to note.

The following example has the same drum pattern six times: twice with no cutoff manipulation, twice with only the kick manipulated, and twice with all three sounds being manipulated:

Fruity Terminology

To avoid confusion, let's start with a few definitions. In most DAW software, a channel is something you'll find in the mixer. You could think of a channel as a sort of pipe through which an audio signal passes. In FL Studio, a channel is something that creates an audio signal. The words channel and generator are used more or less interchangeably to refer to the built-in synths—or, for that matter, to third-party plugin synths.

The pipelines through which sound passes in the FL mixer are called FX. This is guaranteed to be confusing, because effects (FX, in other words) are also the sound-processing widgets that you insert into the FX channels. In this tutorial, I'll use the word “channel” to refer to an audio routing within the mixer, but we'll also discuss the Channel Settings box, which contains the settings for the generators (synths).

FL's basic all-purpose generator is called a sampler. Like most software “samplers,” however, this module plays back digitally recorded sounds. You can't sample (record audio) with it.

Basic Audio Recording

In Part 2 of this tutorial we'll talk about using FL Studio as a MIDI sequencer for external hardware synths. But how do you combine the sound of an external synth with your other FL tracks when it's time to export your final mix as a WAV or MP3 file? Some newcomers to computer recording are puzzled when their external MIDI tracks (that is, tracks that play external hardware synths) can't be heard when a completed song is exported. This happens because MIDI data is not sound data. MIDI is simply a set of instructions that tells a synthesizer what to do. In order to include external MIDI tracks in an exported FL song, the external tracks must first be rendered as audio tracks within FL Studio. To do this, follow these steps:

At this point, a new generator will be created automatically in the Step Sequencer to play the audio track, and the audio track itself will appear in the lower part of the Playlist window. To get good recordings, you'll need to learn a few refinements, such as making sure your input level is high enough to record a noise-free track, yet not so high as to cause distortion. But you now have enough information to transfer external synth tracks into FL Studio as audio.

The Powerful Tang of Sytrus

If you're contemplating purchasing or upgrading FL Studio, I definitely recommend the XXL package, which includes the wonderful Sytrus FM synth (see Figure 3). Except for a few little niggles (for instance, you can't switch off the velocity response, which drives me crazy), Sytrus is easily the most powerful FM synth on the market today, and vastly increases FL's sound palette.

This is not the place for a full tutorial on FM synthesis, about which books have been written. Nor is Sytrus merely a straight-up FM synth. It includes three resonant multimode filters, an additive waveform generator, ring modulation (RM), and a plucked-string algorithm, not to mention effects and a hefty array of envelopes and LFOs. But here are a few Sytrus tips to get you started.

Sytrus comes with an extensive patch library, but you can add to it by downloading and importing patches for the original Yamaha DX7 in MIDI system-exclusive format. These are widely available on the Internet; I got a good batch from Dave Benson's DX7 page. To import a patch, click on the triangle below the Sytrus logo, choose “Yamaha DX7 presets->Import SYSEX,” and navigate to the folder where you've stored your download. When you select a .SYX file, its 32 presets will appear in the Import menu.

Image-Line makes no claim that the patch import process is perfect, as there are some significant differences between Sytrus and the DX7. However, the basic patch will be there, and you can customize it to taste. A good place to start is to add chorus, delay, or reverb in the Sytrus FX page. Then select “Save Preset As” in the Sytrus menu. (Like most windows in FL Studio, Sytrus has its own menu, which you access by clicking the seemingly decorative button at the upper left corner.) Give your new patch a suitable prefix, such as “MyDX.” That way, your new patches will be grouped in the Sytrus preset list.

One good way to start learning Sytrus programming is to load the Default patch, select operator 1 (OP 1), and start playing with the controls in the left half of the panel. (The knobs on the right half are for adding FM and RM.) The ENV and LFO pages are essential.

The first time I selected PITCH->LFO and activated the LFO using the little “on” button in the lower left corner, I was confused, because all of a sudden the sound didn't end immediately when I lifted my finger from the key. A bug? Not really. When any of the envelopes or LFOs is activated, the duration of notes is controlled by the length of the active envelope or LFO. To override this behavior, you have to switch on the VOL->ENV envelope and edit it to taste. The release portions of notes will now be controlled by its release segment(s).

Another point of possible confusion: When you turn the ATT, DEC, SUS, and REL knobs below the Sytrus envelopes, the length of the envelope will change. But when you let go of the knob, the graphic display will snap back to where it was before. Again, this is not a bug. The knobs are multipliers (from 0% to 200%) for the envelope segments you've programmed graphically. Unfortunately, you can't program the ATT knob to respond to key velocity, but you can program an expressive musical pattern by linking this knob to a MIDI Control Change (CC) input or automating it within FL Studio.

Hear It on FM

To start learning FM synthesis, let your eyes travel over to the right side of the Sytrus panel (again, see Figure 3). The knobs form a giant patching matrix. Signals travel from top to bottom and from left to right. The outputs for each of Sytrus's six operators and three filters are in the right two columns, headed FX (which sends signals to the FX page) and OUT (the un-effected output). The rest of the knobs in each row are input knobs. Look at the top row of knobs, for example. This is the patching row for operator 1. The output level of operator 1 is at the right end, and the six knobs in the columns labeled 1 through 6 are used for adding FM or RM to the sound of operator 1 from any of the operators.

You'll note that operator 1 can FM or RM itself. This is called a feedback routing. (Advanced students of synthesis will note that adding RM feedback shouldn't add overtones, but in Sytrus it does. I'm not sure why.) Again, start with the Default patch. After making sure FM is highlighted at the lower left corner of the knob matrix, turn the knob at the intersection of row 1 and column 1 up or down from its center point. The sound will become brighter, changing from a sine wave to something more like a sawtooth:

Turn the 1/1 knob back to its center position (it will become dark), and turn up the 1/2 knob—the one in the top row, not the 2/1 knob, which is at the left end of the second row. Operator 1 is now receiving an FM input from operator 2.

To begin to understand what's possible with FM synthesis, switch to OP2 in the top row of buttons and, while sustaining a note on the keyboard, change the right-hand frequency parameter for OP2 (the one with a little “x” in the lower right corner) from 2 to 3, 4, 5, 6, and so on. The immediate, drastic shifts you're hearing in the tone color are characteristic of FM synthesis. At this point, OP2's volume envelope can be used to shape the tone color of each note:

One more Sytrus trick, to wind things up: Switch to the MAIN page, and in the UNISON section near the top of the panel, drag on the ORD box to produce two or more unison tones per MIDI note. You'll hear a sudden increase in the richness of the sound. Note, however, that unison mode uses up a lot of your computer's CPU cycles. You can get a similar tone color more economically by skipping unison mode, using the knob matrix to send the output of operator 1 to the FX page, and setting the chorus ORD parameter to about 4.

Other Sytrus features worth investigating: Looping envelopes (right-click on envelope points to set the start and end point), the plucked-string algorithm (choose an operator, switch on PLUCK, change the waveform to something other than a sine wave, and edit the DAMP ENV to taste), the various filter modes (pick one), and series filtering (use the NEXT knob in filter 1 or 2).

Still Life with Oranges

In the second part of this series, we'll take a look at some of FL Studio's underlying features, explain how to use it with external hardware, and explore the outer limits of controller data. See you then.