JuanLittleDevil

Multi-band effects units as the name suggests are effects that work on multiple bands of audio independently from one another. Some example of multi-band effects units are: multi-band compressors,  multi-band harmonic exciters, multi-band stereo imagers, etc.

These types of processors are most commonly used in the mastering phase of music production. However there is nothing stopping with you from using it as a creative tool.

In order to understand how multi-band processing works we must also understand how signal flows from source to output. These types of signal processors are typically used as “inserts” so that 100% of the signal is split into “Bands” of frequency ranges. Some mastering plugins come with 4 band multi-pressors as it is the case in Logic’s, waves, and iZotope plugins to name a few. Albeton Live actually offers one multi-band dynamic processor which offers 3 bands of compression and expansion. Each band is then processed independently from each other. Lastly all bands are blended together back into the mix.

Understanding how this work is really the hardest part, from here all we need to do is get a little creative as to how we’ll split these bands up. For my example I’ve chosen to use Ableton’s “EQ Three” as it’s cross-over dial is ideal for choosing which bands we’ll be affecting. Also the “Mute” will act as way to activate only the specific band for that signal path. You can achieve the same effect with an EQ 8 but you’ll need to do a bit more work to ensure your cross-overs are mapped properly, for now we’ll stick with the simplest solution. What we choose to use after each band has been split up is totally up to us.

Here are the basic steps for creating the multi-band unit:

1. Create an effect rack with a single chain.
2. Drop an EQ Three.
3. Map the “FreqLow” and “FreqHi” dials to two separate macros of your choice.
4. Mute the “Low” and “Mid” band, and rename the chain to Hi
5. Right click on the chain and select “Duplicate”, repeat so you have a total of 3 chains.
6. Rename the middle chain to “Mid”, then mute the “Hi” band for that chain and un-mute the “Mid” band.
7. Do the same with the last chain but call it Low. Also change the mutes so only the “Low” frequencies are getting through.

From here you can add your favorite effect unit. For my example I used a utility plugin and simple delay in order to create a multi-band stereo imager take a look at the video to see how this is done.