The Beginner's Guide to Multi-Band Processing

Multi-band processing is something that sends a lot of beginners running for this hills, but brings a smile to every seasoned pro’s face. What’s considered difficult and intimidating to some is actually powerful, flexible – and just a bit misunderstood.

You see, I’m willing to bet that you use multi-band processing in every mix you work on without realizing it. The guitarists and bassists you work with are all using it too, although I’m sure you’d get a strange look from a few if you asked them about it.

Multi-band processing doesn’t have to be complicated. It’s not working in any inconceivable, magical way, and it’s not doing anything you couldn’t find another way to do (although it is usually saving you tons of unnecessary routing and resource-heavy processing to get there).

Instead of feeling overwhelmed by multi-band processing, take a deep breath and dive into the basics with us.

EQ: The O.G. Multi-Band Processing Tool

I told you everyone uses multi-band tools, didn’t I? Whether you’re using an EQ in some larger signal chain or you adjusted the EQ on the guitar amp to get it right at the source, you’re using multi-band processing.

If we break down the term, multi-band just means that the plugins and outboard hardware is breaking out your signal into multiple bands for better, easier processing. Saying “I’ve got a really good EQ” is actually the same as saying “I’ve got a really good set of filters.” In the early days of recording, this is exactly how they described their equalizers.

Luckily, the technology has become more powerful and streamlined. When we say we’ve got a good EQ, engineers know what we’re talking about and what it does without having to dive into how each element of the EQ works.

So the next time you’re in your favorite EQ, think about the ways it breaks your signal into different bands for you. The low-pass, high-pass & each band represent a different processor for you to use.

Once you start looking at dynamic processors in that light, it’s easy to get creative with where that concept can go.

Multi-Band Compression

There have been a few hardware multi-band compressors on the market for years, but the components are expensive and the price tag kept ownership of these tools to the audio elite and mastering facilities.

When you think about the cost, it’s easy to understand why they’re so expensive. Compare what you’re spending on a single channel of hardware compression. Then imagine that same compressor being shoved in a box with 3 more of the same circuit & all of the circuitry necessary to filter down to specific bands.

It’s enough to make your head spin, and a difficult task to achieve in a footprint that won’t take up all of your rack space.

Enter Digital Multi-Band Compression

The first major step the plugin world took toward full multi-band control was with the introduction of multi-band compressors. Without the cost of physical components and physical labor, duplicating the logic of a compressor across multiple bands became infinitely more realistic for plugin manufacturers versus their hardware competitors.

Is a bit more CPU power required for these plugins than a regular compressor? Usually, but it’s much less than it would take to load 3 or 4 compressor instances in your DAW.

Let’s take a look at the process you would need to get the same level of detail in a session without a multi-band compressor:

1. Route each track you want to affect to the number of aux tracks needed (one aux per frequency band)
2. Apply an EQ to each aux track, removing anything you don’t want to affect with hi-pass and low-pass filtering
3. Add your compressor to each aux track. Route each multi-band processing aux back to a single aux track from continuing your processing on the whole instrument.

Sound like a lot of work? It is. Save yourself the hassle and find a multi-band compressor that works with your workflow.

Other Multi-Band Processors

Once you’re comfortable with the concept of multi-band processing, it’s easy to hit the ground running with all of the other capabilities we have. The audio community has barely scratched the surface, and a huge boom is coming as people begin to understand the power multi-band processors have .

Just take a look at Transify:

Transify is JST’s pro-level multi-band transient processor that gives engineers complete control over their transients in 4 frequency ranges. You get crazy amounts of dynamic control over the attack and sustain, as well as a built-in clip circuit for some added aggression that, frankly, wouldn’t be possible in a hardware processor.

I have no doubt that as the technologies built around the concept of multi-band processing, engineers will see more flexibility than ever before. This means more decisive and intentional mix decisions, and the all-important bottom line: better mixes.

What Multi-Band Processors Would You Like To See?

Do you have a particular dynamic processor you’d like to see a variant of? Maybe something time-based ?

Come share it with us over on the Joey Sturgis Tones Forum on Facebook . Thousands of other engineers and producers have already joined the conversation!