Exploring Modulation in Logic Pro X ES2 & EXS24

It's time to take control of your synths and sampler instruments in Logic Pro X! Darren Burgos shows how to use the routing options in ES2 and EXS24 for interesting sonic manipulation.  

Many Logic Pro producers use ES2 and EXS24. Not as many of you know how to use the Router to manipulate and take control of your sounds in fun and interesting ways. In this article I’ll introduce the Router, talk about what it can do, then move on for some fun experimenting.

What is the Router and What Can I Do With it?

That dark strip dividing the two halves of EXS24 and ES2 can look intimidating to some. But like a mixing console in a recoding studio, if you understand a single vertical channel strip, you understand all of them. The 10 identical modules inside the router are used to create “modulations” within EXS24 and ES2. The Router is the bridge between the modulators below it, and the synthesis/filtering above. So what is “modulation” in terms of a synthesizer or sampler? Think of it this way… "What do you want to change, then what do you want to change it with?” The “with” being built-in modulators like an LFO, an Envelope, or bring it into the real world with your MIDI controller. The “what” are things like Filter Cutoff, Sample Start Position, Pitch, Waveform selection, Detuning, and Glide Speed.

Pic 1

What Should You Modulate?

So what should you modulate? Think about how you want your patch to sound. Pitch is always a popular target, and is often found pre-assigned in various built-in sounds like organs to add a bit of funk while playing and moving the mod wheel. More uncommonly, you could control the rate of an LFO with an envelope to create spinning crescendos (like a spun coin settling). What about modulating the volume on a sound with an LFO to create a gated effect? With hundred of source/target combinations, and up to ten simultaneously, the sky nearly is the limit for twisting and shaping your sounds.

Pic 2

Overview of a Router Module

First let’s take a look at a single Router “module” in an ES2 to understand what they’re capable of. There are very little differences between ES2 and EXS24’s Router, so if you get one, you’ll get the other.

Pic 3

Each of the ten Router modules are identical. Let’s start by looking at one from the bottom up. With the Source menu, you select the various modulation sources like any of the LFOs, or Envelopes. You can also choose things like note velocity and in ES2, two very cool randomizers are available. Basically, the Source menu on both ES2 and EXS24 is used to select what you want to modulate with. Directly above the Source is the Via menu. This allows you to select a MIDI controller like the mod wheel or pitch bend as a physical control to mix-in the modulation effect itself. Keep in mind that the Via menu can’t modulate on its own… it needs the Source below it. Finally, at the very top is the Target menu (Destination menu in EXS24), where you choose what will actually be modulated by the source you chose below. Detune, Cutoff, Pitch, and Amp are commonly used, but the list stretches on with up to 40 different choices.

Pic 4

Notice the small green triangle on the right side? It’s actually a set of triangles (one green/one orange) when you make a selection from the Via menu. There is a tiny centered zero position on the slider the triangle(s) are connected to (you can click it to recenter it). When these “intensity” triangle(s) are positioned above the center, they allows the Source to modulate the Destination/Target. Moving them below the line has a negative effect on the destination/target. When you choose a value from the Via menu like the mod wheel, green is the bottom value (mod wheel at its bottom position) and the orange is the top value (mod wheel in its top position). There is also a Bypass button and up to two Invert buttons for flipping parameters in the Router module.

Pic 5

Give a Sound a Detuned Analog Feel in ES2

Let’s add a detuned analog feel to ES2’s factory default sound. From any available Router module, I’ll choose “Detune” from the target menu. You can tell if a module is being utilized by the top target menu on each of them. If it says “off,” or is a darker color than the others, it’s not being used. Now from the bottom Source menu, choose LFO1. Raise the module’s green intensity slider above the tiny zero (center) position. Set it to around 0.14 and play with the sound. This gives the basic ES2 sound a bit more vibe. Try adjusting LFO1’s rate slider with very slow or very fast values. Go back to the triangle and try different positions.

Pic 6

Randomize the Cutoff on Different Notes in ES2

Now Let’s randomize the Filter so that on every new note press, a different filter position will be chosen. From another available router module select Cut 1+2 from the Target menu. From the Source menu select “RndNO2.” Play the sound and slowly raise the value of the green triangle. This modulation routing works great with the arpeggiator!

Pic 7

Add a Gated Effect to Sounds in EXS24

Let’s move on to the EXS24 now. From the black preset area above the filter, select the “Stacky Hook” sound from the Synthesizer > Synth Leads menu. It’s easy to create a “gated” sound in the Router. From the “target” menu of any available module, select “Volume.” From the Source menu below it, choose LFO2. Set LFO2’s Rate knob to 1/16th note value, and change the Wave to an upward sawtooth. Slide the green triangle up in the Router and you should hear a nice tempo synchronized gated effect. Try different LFO2 rates and repositioning the green triangle.

Pic 8

Make Notes Play at Different Lengths in EXS24

Now let’s use the Router to make a synth sound play shorter notes when playing lighter velocities. Again choose from the Synthesizer > Synth Leads menu, but select JP8 Unison Saw this time. Go straight to envelope 2 and lower the sustain all the way down. In an available Router module select Env2 Decay from the Destination/Target menu and Velocity from the Source menu. Now slide up the green amount triangle to around half way up. Playing very lightly triggers a short more staccato sound, while playing harder extends the decay.

Pic 9

Thanks for reading, and happy modulating!

Darren started making music on computers when he was a teenager in 1987. His first computer was an Amiga, and when he realized the power of computer-based production, his addiction for making electronic music began. Darren switched to Mac in 1994 and started using Logic Pro. He's been involved in many music projects over the years incl... Read More


Want to join the discussion?

Create an account or login to get started!