Sidechain Compression FAQs for Modern Metal Mixes

Modern metal is a beast. We’re dealing with 8-string guitars tuned to oblivion, dense synth layers, drum samples hitting like cannons, and vocals that need to slice through it all. The result? A frequency spectrum that’s completely slammed from top to bottom. This is where getting elements to sit together without turning into a chaotic mush becomes the number one job of the mix engineer.

Enter sidechain compression. It’s not just a fancy EDM trick for pumping pads; it’s one of the most powerful tools for creating clarity, punch, and space in a brutal metal mix. If you’ve heard of it but aren’t sure how to apply it to your sessions, or you’re just looking for some new tricks, you’re in the right place.

Let’s dive into the most common questions about using sidechain compression to make your metal mixes hit harder.

WTF Is Sidechain Compression Anyway?

Think of a standard compressor as an automatic volume knob. When a signal (like a vocal) gets too loud and crosses a threshold, the compressor turns it down. Simple enough.

Sidechain compression separates the detection from the action. It still turns a signal down, but it uses a different signal as the trigger.

Imagine a bouncer at a club (the compressor on your bass track). The bouncer is watching the door. Normally, he only acts when the people inside the club get too rowdy. With sidechaining, he’s watching the VIP line outside (the kick drum). Every time a VIP (a kick hit) comes to the door, the bouncer tells the regular crowd inside (the bass) to quiet down for a split second to let the VIP through.

In short: you’re using one instrument to control the volume of another. In a dense metal mix, this is crucial for creating temporary pockets of space exactly when you need them.

The Classic Move: Kick & Bass Sidechaining

This is the most common use of sidechaining, and for good reason. In modern metal, where low-tuned guitars often dip into the bass guitar’s territory, getting the kick and bass to play nice is non-negotiable. You want the deep low-end weight of the bass, but you need the transient thump of the kick to cut through.

Why It’s Non-Negotiable in Modern Metal

The low-end in today’s metal is crowded. You might have an 8-string guitar chugging a low F#, a bass guitar playing the same note, and a kick drum with a fundamental at 60Hz. If they all hit at once, you get a muddy, undefined mess. Sidechaining allows the kick to punch through that wall of low-end for a millisecond before letting the bass take over again. It’s the key to getting a low-end that is both powerful and clear.

Actionable Settings & Plugin Examples

You can do this with any stock compressor that has a sidechain input, but plugins like FabFilter’s Pro-C 2 or the Waves SSL G-Master Buss Compressor make it super easy.

1. Insert the compressor on your bass guitar track (or bass bus).
2. Activate the external sidechain input and route your kick drum track to it. Make sure you’re sending the signal pre-fader so the kick’s fader level doesn’t affect the sidechain amount.
3. Dial in your settings. Here’s a great starting point:
   • Attack: As fast as it can go (often 0.01ms – 1ms). You want the bass to get out of the way instantly when the kick hits.
   • Release: This is crucial. Time it to the song’s groove. A good starting point is between 50ms and 150ms. You want the bass to return to full volume smoothly before the next kick hits. Too short, and it sounds unnatural. Too long, and it “sucks the life” out of the bass.
   • Ratio: Start around 4:1. Go higher for a more aggressive ducking effect.
   • Threshold: Pull this down until you see the gain reduction meter moving with every kick hit. Aim for about 3-6dB of gain reduction. You want to feel it more than you hear it.

Check out our full guide to metal compression secrets for more deep dives into dynamics.

How Do I Make Vocals Cut Through the Guitar Wall?

You’ve got four tracks of down-tuned, high-gain guitars. They sound massive on their own, but the second the vocalist comes in, they get completely swallowed. You could try carving out space with EQ, but that can thin out your guitar tone. A much more elegant solution is sidechaining.

The Solution: Sidechaining Guitars to the Vocal

By inserting a compressor on your rhythm guitar bus and sidechaining it to the lead vocal track, you can make the guitars subtly duck in volume whenever the vocalist is singing. This creates a pocket for the vocal to sit in without you having to hack up your guitar tone with static EQ.

Going Deeper: Multi-Band Sidechaining

Taking this a step further is what separates the pros. The most important frequencies for vocal intelligibility are in the midrange (around 1kHz – 4kHz). This is also where high-gain guitars have a lot of aggressive energy.

Instead of ducking the entire guitar signal, use a multi-band compressor like FabFilter Pro-MB or Waves C6.

1. Insert Pro-MB on your guitar bus.
2. Create a band centered around the vocal’s core frequencies (e.g., 1kHz – 4kHz).
3. Engage the external sidechain for that band only and feed it from the vocal track.
4. Set a fast attack and medium release.
5. Lower the threshold so that band of guitar frequencies ducks by 2-4dB only when the vocalist sings.

The result? The guitars stay powerful and full in the low-end and high-end, but the clashing midrange ducks out of the way, letting the vocal sit perfectly in the mix. It’s a transparent and incredibly effective trick. For more on this, mastering EQing modern metal guitars is key.

Can I Use Sidechaining for That Electronic/Synth-Heavy Metal Sound?

Absolutely. Modern metal is blurring lines with other genres, pulling influence from electronic music, hip-hop, and pop. Bands like Bring Me The Horizon, Falling In Reverse, and Spiritbox regularly use massive synth pads, arpeggiators, and 808s. Sidechaining is fundamental to that sound.

To get that rhythmic “pumping” sound on a synth pad or string layer, simply sidechain it to the kick drum. Unlike the subtle kick/bass trick, you can be much more aggressive here.

• Deeper Threshold: Aim for 10dB or more of gain reduction.
• Slower Release: Time the release so the pad swells back up in time with the song, creating that signature rhythmic pulse. A dotted 8th note is often a good starting point.
• Plugins like Xfer’s LFO Tool or Cableguys’ ShaperBox are made for this, allowing you to draw in the exact volume curve you want instead of relying on compressor settings.

What Are Some Creative/Advanced Sidechain Tricks?

Once you’ve mastered the basics, you can start using sidechaining to add dynamic excitement and polish to your mix.

Adding Punch to Drum Rooms

Want your snare to sound explosive? Put a compressor on your drum room mics or overheads and sidechain it to your close-mic snare track. Set a very fast attack and time the release to the groove. Every time the snare hits, the room mics will duck for a split second and then swell back in, creating a “whooshing” or “breathing” effect that makes the snare feel massive.

Cleaning Up Vocal Reverbs & Delays

Huge reverb and long delays sound awesome, but they can easily wash out a vocal and destroy its clarity. The solution? Sidechain your reverb!

1. Put your reverb plugin on an aux/return track.
2. After the reverb, insert a compressor.
3. Sidechain that compressor to the dry lead vocal track.
4. Set it so the reverb gets turned down by 4-6dB whenever the vocalist is singing and returns to full volume in the gaps between words and phrases.

Putting It All Into Practice

Sidechain compression isn’t just a tool; it’s a mindset. It’s about thinking dynamically and making elements in your mix interact with each other to create space, punch, and clarity. From the fundamental kick/bass relationship to advanced vocal and drum tricks, it’s an essential technique for achieving the polished, powerful sound expected of modern metal.

Reading about settings is one thing. But watching a producer like Will Putney or Joey Sturgis actually dial in these techniques on a real track from bands like Periphery or August Burns Red is a complete game-changer.

At Nail The Mix, you can do exactly that. Every month, you get the raw multi-tracks from a real metal song and watch the original producer mix it from scratch, explaining every single move. You can see how our world-class instructors use sidechaining and hundreds of other techniques to craft their signature sounds. Check out our entire catalog of sessions and see for yourself.