In the previous articles we discussed how to setup effects racks using parallel chains to process incoming audio in different ways. Hopefully those discussions proved useful and were able to help you generate some new ideas, but we can take it a step further. What if wanted to process different parts of the audio differently? Different frequencies, different channels, or different parts of the stereo spectrum are all easily available to us within Live using the flexibility of racks, and a handful of native Live devices.
Splitting audio into smaller parts like this can be a powerful tool for both sound design and creation, as well as mixing and polishing audio. I often find myself wanting to treat the low end of a sound much differently than the high end, and splitting the audio will facilitate these types of tasks.
You can grab the set with all of the devices HERE. This includes two multiband splitters, and two mid-side splitters, each done in slightly different ways.
Let’s start with the multiband processing. You can split it up into as many bands as you’d like, but let’s just start with a low band, a mid band and a high band, similar to Live’s own Multiband Dynamics device. Start by dragging an empty Audio Effects Rack onto a channel, then dragging an EQ3 down into the rack where it says ‘Drop Audio Effects Here’. A great thing about racks, is that macros can be assigned to multiple destinations anywhere within the rack, and we are going to take advantage of that to make this rack easily tweakable. Start by mapping the the ‘FreqLow’ knob to the first Macro of the rack by right-clicking and selecting ‘Map to Macro 1’. Then map the ‘FreqHi’ knob to the second macro. So know we have a DJ style eq within a rack, but we want each of those bands freely accessible. Duplicate the chain twice, and rename the chains to Low, Mid, and High, then go through and turn off the mid and high bands for the Low chain (by clicking on the ‘M’, and ‘H’ buttons), and repeat this for the other chains, turning off the bands we don’t want to hear. We now have three frequency bands exposed for processing, and the crossovers are all mapped to the same knobs to make adjusting the bands a breeze.
I’ve also mapped the filter slope switch to a macro so you can choose between 48 db/octave, and 24db/octave. The final step is to add some level control by mapping some macros to the gain of the active band of each EQ, or the volume of the chains in the chain editor. The difference in these can be compared to having the volume control pre FX, or post FX if you put any processing on the chain after the EQ3.
I’ve also included a multiband splitter made with EQ8s that has an added ‘Resonance’ parameter, and it also shows a technique for defining parameter ranges on macros that you usually can’t define. When putting this rack together I realized the I couldn’t define the range of the Filter type, so the knob would freely select between the eight different types, when I only wanted to choose between the 12db/octave and 48db/octave high and low pass filters. The way around this is to nest this rack within another rack. You can define ranges of macros mapped to macros, thereby defining the range of the parameter mapped to that macro (that’s a confusing sentence, I hope it makes sense). You can see this in action if you check out the ‘Filter Type’ Macro.
Now that you have the ability to process audio per frequency band, you can set up some very elaborate processing or mixing chains. You could recreate the Multiband dynamics with compressors that can be sidechained to different elements of drum rack. You could really give frequency bands their own character and space in a mic with tools such as these.
Another useful way to process audio in separate bands is the mid-side approach. It’s a practice born from a recording technique, that involves translating a stereo signal into a middle and side component. The mid equals the left plus the right, and the side equals the left minus the right. Or if it helps, the side equals the left plus the a phase inverted right. This splits the audio into 2 signals, one that contains everything that is the same between the channels(the mid), and everything that is different between the signals (the side). There are plugins that do this for you, but it’s nice to know the process.
There are few ways to accomplish mid-side processing in Live, and each has their 
advantages. The first, and simplest, approach is to use 2 utility devices in parallel in a rack, and set one’s width to 0% (this will be the mid), and set the other’s width to 200% (this will be the sides).
With this approach you can now process the two streams separately, or simply experiment with the perceived width and depth of the signal with simple volume adjustments of the two bands.
The next way is to use the built in Mid-Side Mode of the EQ8. There’s a button along the right side of of the device, that allows you to switch between three different modes of the EQ8. Stereo, Left/Right, and Mid/Side. I wouldn’t be surprised if you’ve never touched this particular option, as it’s not widely discussed as far as I know.
If you select M/S from this menu, EQ8 will switch to it’s mid side mode, where you can apply different curves to the mid and side portions of the signal by clicking the button labelled ‘M’ in the above screenshot. This is useful for mixing tasks, such as taking all of the sub frequencies out of the sides to reduce muddiness or phasing issues that can arise. Or you might want to just add some high frequency energy to the stereo pads without really affecting the snare drum thats coming right down the center.
The final way (at least the final way I will discuss in this article) to get some mid-side goodness is kind of a combination of the two previous approaches. Although it doesn’t give you any distinct advantages over the first (utility based) approach, it does demonstrate that there are SO many different ways to do things in Live. Start by creating an empty effects rack and dragging two EQ8s down onto it in separate chains. Switch both the Mid-Side mode, and cut all the mid out of one (with a low pass set to 0 Hz, or a high pass set to 20 kHz), and all the sides out of the other (using the same technique). This presents us with separate mid and side channels each with the ability to shape the EQ curve right then and there.
There are tons of functional and creative uses for multiband processing, and I encourage you to explore the possibilities with processing individual frequency bands, or individual components of a stereo signal. Any questions, comments and concerns can be sent to evanbeta@keithmcmillen.com. If you haven’t read them yet, and are interested in more discussions on racks be sure to check out the previous two articles in the series here: Live Effect Racks for Utility and Creativity and Live Effect Racks for Performance and Manipulation.