How To Mix Low End: A Metal Producer’s Guide

We’ve all been there. You’ve got a killer kick sample, a gnarly bass tone, and downtuned 8-string guitars that should shake the foundation of your house. But when you put them all together in the mix, you get… mud. A blurry, undefined, powerless mess where nothing seems to have its own space.

Your first instinct is probably to reach for an EQ, maybe a high-pass filter, and start carving. You might try some sidechain compression to get the bass to duck out of the way of the kick. These are valid tools, for sure. But what if the core of your problem isn't about frequency, but about a single button that most producers ignore?

Before you touch a single EQ band, you need to understand and use the most powerful, and most overlooked, tool for cleaning up your low end: the polarity switch.

What is Polarity and Why Does It Wreck Your Low End?

Your speakers create sound by pushing and pulling air. Low frequencies, with their long, powerful waveforms, cause the biggest pushes and pulls. The problem starts when you have two low-end heavy instruments—like a kick drum and a bass guitar—playing at the same time and telling your speaker to push and pull simultaneously.

When one waveform is going up (pushing) while the other is going down (pulling), they cancel each other out. The result? A hollow, thin sound with a fraction of the power you recorded. This is called phase cancellation, and it’s the number one killer of a punchy, aggressive low end.

Phase vs. Polarity: The Quick and Dirty

You'll hear people use the terms "phase" and "polarity" interchangeably, but they're slightly different.

• Phase is a time relationship. If two identical signals are 180 degrees out of phase, they cancel completely.
• Polarity is simpler. Flipping the polarity just inverts the waveform. The positive parts become negative, and the negative parts become positive.

That little button in your DAW, often marked with a "Ø" symbol, is a polarity switch. It flips the waveform a perfect 180 degrees. While the problem is technically phase cancellation, the polarity button is often the instant fix.

The Polarity Flip: Your New Go-To Low End Tool

This simple button can be just as powerful as EQ and compression, especially for the low end. It should be the very first thing you check when combining low-frequency elements. Most DAWs have a stock utility plugin with this function. In Pro Tools it’s the Trim plugin; in Logic Pro, it’s the Gain plugin. Find it, favorite it, and get ready to use it on every mix.

The "Flip First, EQ Second" Workflow

Adopt this mindset and it will change your mixes forever. Before you start surgically removing frequencies, you need to make sure your tracks are working together, not fighting against each other.

Kick and Bass: The Classic Conflict

This is the most common place you’ll find destructive phase issues. The fix is stupidly simple.

1. Solo your kick drum and your bass guitar.
2. Listen closely to the combined impact of the low end. Feel the punch.
3. Now, insert a utility plugin on your bass track and hit the polarity flip (Ø) button.
4. Listen again.

Does the low end suddenly sound fuller, deeper, and more powerful? Or did it get weaker and hollower? There is no "right" way. The right way is whichever one sounds better. Nine times out of ten, one position will be dramatically better than the other. You’ve just fixed a massive low-end problem with a single click, without even thinking about an EQ for your metal mix.

Multi-Mic'd Sources (Drums & Guitars)

This technique is crucial for anything recorded with more than one microphone.

• Drums: The relationship between drum mics is a minefield of phase issues. A classic example is the snare top and snare bottom mic. The bottom mic's waveform will be a near-perfect mirror image of the top mic's, because it's capturing the skin moving in the opposite direction. You should almost always flip the polarity on the snare bottom mic to bring back the body and weight of the snare. The same goes for kick in vs. kick out mics. Check their relationship. Check them against the overheads.
• Guitars: Using the classic combo of a Shure SM57 and a Royer R-121 on a guitar cab? Or a two-mic Fredman setup? Flip the polarity on one of them and see which one gives you the thickest, meatiest tone. The phase relationship between mics is what gives these techniques their character, but a polarity mismatch can ruin it.

It’s Not Just for Bass and Drums

This concept applies to any instruments that occupy a similar frequency range. Low-tuned guitars fighting with the bass? Check their polarity. Stacked synth basses and 808s? Check their polarity.

This technique is so fundamental that a lot of pro mixers use it instinctively. On the URM Podcast, Jaki King talked about how crucial this is to his entire mixing style. We even saw it in action on Nail The Mix when Kane Churko (one of our many world-class instructors) was mixing Papa Roach. He put a utility plugin on his master fader and would A/B the polarity of the entire mix to see which way felt punchier coming out of his speakers. That’s how deep this goes.

Advanced Phase Alignment: The Next Level

A polarity flip is a blunt, 180-degree tool. Sometimes it gets you 90% of the way there, but things could still be tighter. This is where you move from polarity to true phase alignment.

Using Phase Alignment Plugins

If you want to get surgical, dedicated plugins are the way to go. Tools like Sound Radix Auto-Align or Waves InPhase are designed for this. You feed them two signals (like your kick in and DI tracks), and they will calculate the exact millisecond delay needed to get the waveforms perfectly in sync. It’s an absolute game-changer for getting multi-mic'd drums to sound massive, turning a good snare sound into an explosive one.

Manual Nudging: The Old-School Way

Don’t have a fancy plugin? You can do it by hand.

1. Zoom way in on the waveforms of your kick and bass tracks in your DAW’s edit window.
2. Look at the initial transient of each sound.
3. Nudge the audio clip of one of the tracks forward or backward by just a few milliseconds.
4. Listen for the "sweet spot" where the low end punches the hardest. This takes more time, but it’s a powerful way to understand how small timing changes have a huge impact on your low end.

Putting It Into Practice: Learning From The Pros

Getting a massive, clear, and powerful low end is the foundation of any great metal mix. The key is to address the most fundamental issues first.

• Always check polarity relationships between low-end elements before you EQ.
• Pay close attention to multi-mic'd sources like drums and guitars.
• Once polarity is set, then you can reach for tools like compression and EQ to further shape your sound.

Knowing the theory is one thing, but seeing it applied in a real-world session is what makes it all click. Imagine watching the actual producer of a massive album dial in the kick and bass, flip polarity to find the punch, and explain every single decision along the way.

That’s exactly what we do at Nail The Mix. Every month, you get the full multi-tracks from a real metal song and watch a pro producer mix it from scratch in a 6-8 hour livestream. You can see how guys like Joey Sturgis, Will Putney, and dozens more tackle these exact low-end issues on every single mix. Check out the full catalog of past sessions to see what you've been missing.

And if you want to dive even deeper into this and hundreds of other pro production techniques, we have over 1,500 more tutorials just like this one available right now as part of URM Enhanced. Stop fighting your low end and start making it powerful.