Logic Pro: Creating Effects Macros

Apple Logic Pro: Tips & Techniques
By Paul White

Smart Controls allow you to control multiple parameters across multiple plug‑ins on a single track, using just one set of controls — or even just one knob!

Logic’s Smart Controls allow you to create hands‑on effects macros.

Logic Pro’s Smart Controls seem to be somewhat neglected by seasoned Logic users, and I suspect that’s because they offer a simplified, GarageBand‑style view of plug‑ins that is at odds with the way most experienced users tend to interact with Logic. I have to admit to neglecting them myself as I couldn’t see what benefits they would bring to my workflow — until I explored one of their under‑appreciated superpowers.

I was reviewing Slate Audio’s Storch Filter plug‑in, a simple one‑knob affair that simultaneously closes down a filter while increasing the amount of added effects as the cutoff frequency is turned down, and wondered if I could set up something similar in Logic. It is certainly a useful effect for use in EDM to create a sense of distance: adding reverb and possibly some kind of modulation as the filter closes gives the impression of the sound melting away. It turns out that the solution to controlling multiple plug‑in parameters from a single knob is tucked away in Logic’s Smart Controls section.

By default, Smart Controls will typically show the most relevant controls of the first one or two inserted plug‑ins, depending on whether you start from a preset or not. The actual controls you see are different on an instrument track, but these general instructions work on those too. Any of the knobs that appear can be reassigned to control any of the parameters on any plug‑in inserted on that track (or bus or master) and the parameter name shown above the knobs can also be changed as required. If you’re using Smart Controls on a bus or main output, these first need to be made visible in the Main arrange screen, which you can do by selecting the required bus or output in the mixer view, then using Ctrl‑click to open a menu, from which you select Add Track. You can also use the key command Ctrl+T.

Smart Controls are, at their most basic, a very useful tool for cutting through the clutter of very busy plug‑ins when you just need to access a small number of parameters. The Smart Control knobs can be automated in the same way as most other plug‑in controls, but to create our ‘several things happening at once’ control, we need to assign multiple plug‑in parameters to a single Smart Control knob to create a macro. Each parameter can be given its own control range and can go in either a normal or reversed direction plus, if you need it, there’s graphical adjustment of the control range for each parameter to allow its default linear operation to be changed.

For my take on an effected filter, which I am using as my example here, I set up a high‑cut filter followed by a SilverVerb reverb and a Flanger plug‑in, the idea being that as a Smart Control is turned anti‑clockwise to close down the filter, more reverb is mixed in and the flanger Mix control is advanced. Once you have something useful, you can save it as a user Channel Strip Setting. As with other Channel Strip Settings, you should create separate ones for audio tracks, instrument tracks, busses and the main output. For example, you won’t see a user Channel Strip Setting showing up in a bus’s User Settings submenu.

Here’s a step‑by step approach to setting up your own macro knob to give you control over several functions at the same time. There may well be other ways to achieve the same result in Logic Pro X, but this method works for me.

Behind the scenes of the Splurge Filter: turning the Smart Control macro knob simultaneously lowers the cutoff of the low‑pass filter in the Single Band EQ, increases the Flanger’s Mix parameter, and turns up the Wet control on the SilverVerb.

Smart Moves

Let’s assume that we want to create our filter effect to be used on a single audio track, though the process is essentially the same if you want to process an instrument track, a bus or main output as long as they are visible in the main Arrange page. If I’m creating an instrument track macro, I’ll choose a low‑horsepower plug‑in as part of my Channel Strip setting then change it to the instrument I want after the user Channel Strip Setting has loaded.

First, insert the plug‑ins that you want to use in the Channel Strip — in my example I’m using a single‑band EQ, a SilverVerb and a Flanger — then leave the track selected and use the knob icon that is fifth from the left at the top of Logic’s Main screen to open Smart Controls. Alternatively, if you haven’t changed the default key commands, pressing the B key should get you there. Make sure the selection buttons at the top left of the Smart Controls pane are set to Track and not Master.

A Smart Controls panel will appear with some parameters already mapped out, and at this point it doesn’t matter if they are the parameters you need or not. By default, each knob controls a single parameter. For our example, we only need to reconfigure a single knob, as we’re going to be assigning all our variable parameters to it. I’ve used the control knob at the top left of the Automatic Smart Controls panel. Should you want to clear all the current control mappings, click the cog icon, then click Delete All Patch Mappings. You can then assign any of the other knobs for another task. Click on a knob to select it and you’ll see a faint blueish glow around the knob’s edge.

On The Map

Click the ‘i’ button at the left of the Automatic Smart Controls window and a panel will drop down. This is where the parameter mapping takes place. Click the down arrow to the left of the words Parameter Mapping. If you’ve cleared all the mappings, the control will show up as Unmapped; otherwise, you’ll see the parameter currently mapped to the selected Smart Control knob. The tiny up/down arrows immediately to the right of the parameter name access a menu tree that allow you to reassign the knob to any of the available plug‑in parameters for any of your inserted plug‑ins — and this also works with most third‑party plug‑in parameters. Note that you can also incorporate your track’s volume and pan controls into a macro. What you can’t do is tie together plug‑in parameters from different tracks: Smart Controls apply only to the track to which they are attached.

Select the top left knob in Smart Controls and then use the Parameter Mapping line to navigate your way to the Single Band EQ filter cutoff, ensuring that the plug‑in is set as a high‑cut filter. You can set the slope and resonance using the plug‑in’s usual controls. You probably don’t want the filter ever to close fully, so set its lower limit to around 200Hz. You can also assign parameters by clicking Learn and then selecting the relevant knob or slider in your plug‑in window.

Next we need to assign the reverb’s Wet control to the same knob. To do this, click the down arrow next to the cog icon and then click Add Mapping. This creates another row entitled Unmapped, whereupon we can again use the small up/down arrows to open up the assignment options and this time navigate to the SilverVerb’s Wet parameter. We want this parameter to increase in value as the filter is closed down, so click Invert in the box below. Add another mapping assignment in the same way and this time select the Flanger’s Mix control, again clicking Invert, as we want the flanging to get deeper as the filter closes down. In the range boxes below, set the minimum flanger mix value to 0 and the maximum to 50. If this gets you where you need to be, then you can save the Channel Strip Setting. I’ve called mine Splurge Filter.

Ultimate Control

Should you want to refine your macro a little more before saving it, then (providing Invert is not clicked) clicking Open next to the word Scaling brings up a graphical editor with a selection of ready‑made curves and its own option to invert the direction of the curve. You can also click to add or drag points to create a control law of your own — for example, one that changes direction halfway through, or an effect that only comes in at all below the halfway setting of your macro knob. You might also want to change the name of the Smart Control knob to match your plug‑in combination, in which case you can just edit whatever name is showing at the top of the Automatic Smart Controls panel. Should you want to create variations on the Smart Control macro that you’ve created, you can select multiple lines in the assignment section and then use copy and paste to assign those lines to a new Smart Control knob.

The more you think about macros, the more uses you can find for them.

The more you think about macros, the more uses you can find for them. For example, if you are in the habit of using two or more compressors to achieve a specific result, you can assign their threshold knobs to a single Smart Control and also add in a make‑up gain control so that the level stays nominally even as you add more compression. Similarly, you may want to set up a multiband EQ with each band assigned to a Smart Control knob, possibly each with a different range, so that you can turn all the band gains up or down together, adding output level compensation by assigning the output level control to your macro such that you can hear the EQ changes without being distracted by changes in loudness. This approach is useful for creating a vocal processing strip with two or more macro knobs (one for EQ and one for compression, for example). You can also set up all manner of effects using the same technique — imagine a single control adjusting both high‑ and low‑pass filters at the same time while adding distortion from an overdrive plug‑in to morph into a telephone or transistor radio‑style vocal effect.

As they say on the packet, what you can do is limited only by your own imagination. It may take a little juggling to get these combinations working just as you want them, but once you have refined them they will always be available to call up when you need them again in the future.

Published October 2023

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