Distortion is an invaluable tool in the mixing engineer's toolbox. However, overly distorted mixes can often sound terrible, especially when the distortion is less than a creative choice and more of a technical mistake. Whether you're dealing with cleaning up a distorted mix or doing things that create distorted mixes, you've come to the right place to help you mitigate unwanted mix distortion.
The top 6 reasons your mixes sound distorted are:
- Digital Clipping
- Too Much High-End
- Too Much Limiting
- Distorted Recordings
- Distorted Playback
Let's discuss these reasons in greater detail throughout this article and investigate a few strategies to fix each issue. Before we get started, though, let's consider how we can tell whether our mix is distorted or not.
How To Tell If Your Mix Is Distorted
Audio distortion, technically speaking, is any form of deformation of the waveform. Practically all processes and effects will change the shape of the mix's waveforms to some degree. Distortion as an effect or artifact tends to shape the tops and bottoms of the waveforms (the amplitude extremes) more than the mean amplitudes.
Distortion can sound like many different things in a mix. It can cause an overly harsh mix, an overly muffled mix, poor definition of transients, bad signal-to-noise ratios, poor dynamic range, and more. It can even sound sonically pleasing in many instances to add extra colour, grittiness or special effect to the mix.
If the mix's audio sounds like it's started to break up, become ill-defined, noisy or harsh, or unrecognizable from the sum of its parts, you're likely dealing with distortion.
As we'll discuss in the section on distorted playback, it's important to have proper monitoring that accurately represents the mix. This means monitors and headphones with flat frequency responses and maybe even a subwoofer to cover the low end. It also means proper room acoustic and acoustic treatment when monitoring through studio monitors.
If we can't hear our mix accurately, we'll have a more difficult time finding and addressing issues of distortion and more.
Another important tool for understanding distortion issues in our mixes is using reference mixes.
A reference mix (or reference track) is an audio mix/track that we can compare our work against as we make our way through the mixing process. A reference track is typically in the same style/genre as what we're working on and acts as a goal post to work toward in terms of mix aesthetic.
It's sometimes the case that a bit of distortion is commonplace for a specific genre. In that case, you may want to maintain a bit of distortion to fit in with the crowd or, alternatively, to create a more “technically proper” mix without as much distortion.
By A/Bing our mix against a reference, we can get quick feedback as to whether our mix is brighter or darker. If we've chosen a reference mix that's decently bright and our mix is very dark in comparison, we'll likely have to make some adjustments to reduce muffling and increase the overall brightness.
I have a video going into detail regarding reference mixed. Check it out here:
For more information on reference mixes and A/B testing, check out the following My New Microphone articles:
• Mixing: What Are Reference Mixes & Why Are They Important?
• A/B Testing & Its Importance In Mixing (With 5 Best Tests)
Now, distortion can be a useful effect in the mix on specific tracks, buses and even the mix bus. However, this distortion is generally harmonically pleasing or, at the very least, well thought out for the specific mix. This article will focus more on the unwanted distortion that may plague the entire mix.
Digital clipping in the mix is a sure way to get distorted results. Digital clipping happens when a digital audio system is pushed past its absolute maximum of 0 dBFS (decibels full scale). At this point, the tops and bottoms of the digital audio signal are cut off at the maximum level achievable.
To visualize this, I put together the following image. The vertical dotted lines represent full scale. The blue/left signal is well within the boundaries of full scale, but if we apply too much gain to the signal (becoming the red/right signal) and exceed these boundaries, we end up with hard digital clipping.
The square-like waveshaping caused by digital clipping can yield negative mix results, including break up, poor definition, noise, harshness, or, when pushed far, an unrecognizable change from the original audio.
So digital clipping is typically best avoided, and it's no wonder it's such a commonly addressed enemy in audio production.
How To Fix/Avoid Digital Clipping
Avoiding digital clipping is simple: do not exceed 0 dBFS. As I mentioned previously, 0 dBFS is the absolute ceiling for digital systems. Trying to exceed it will cause gross deformation to the audio signal as the extremes get cut off.
This is also true in 32-bit floating point systems that technically have much more headroom. The audio will ultimately be bounced down to formats and played back in systems with the same 0 dBFS ceiling, so even though 32-bit float offers us protection within our digital audio workstations, it won't protect us in exporting or bouncing our music.
On the recording side of things, it's essential that we don't record too hot on the way into our digital systems.
When recording digitally, say from a virtual instrument, we should maintain a decent amount of headroom.
When recording from analog sources (microphones, direct injects, analog samplers/synthesizers), we should also be aware that our analog-to-digital converters can be overloaded, too. In many cases, these ADCs will begin distorting well before the full 0 dBFS point, so it's generally best to record lower if possible.
If a signal is printed with digital distortion/clipping, there isn't much we can do with levels to fix the issue. However, there are “de-clipper” plugins on the market that can help us, to varying degrees, reduce the effects of clipping by effectively reconstructing the clipped waveform to an unclipped version.
This takes us to gain staging, which is the act of feeding each device in a signal chain with optimal signal level. Gain staging applies to both analog and digital systems, though it's doubly important in analog to ensure proper signal-to-noise ratios.
Analog devices inherently introduce noise into the audio signals passing through them, so it's critical to drive them with strong enough signals to overcome the noise and have good signal-to-noise ratios. We're not as concerned with noise in digital systems, so we can drive them with less signal level to be safe and avoid digital clipping.
Gain staging in mixing is also important for avoiding digital clipping in our tracks, buses and mix bus. By setting our tracks to healthy levels of -20 to -18 dBFS, we can drive our plugins with healthy levels, avoid clipping any individual track, and in most cases, avoid clipping the mix bus as well.
I have a video dedicated to gain staging and how to do it in digital audio workstations. You can check it out here:
For more information on gain staging and headroom, check out the following My New Microphone articles:
• Mixing: What Is Gain Staging & Why Is It Important?
• What Is Headroom In Audio? (Recording, Mixing & Mastering)
Finally, when maximizing the loudness of the mix or master bus, we should ensure that the true peak output of the mix/master is not only below 0 dBFS to be safe but also below whatever the specifications are for the ultimate use of the bounced audio.
For example, it's common for streaming services to request a -1 dBFS true peak due to the file format conversions and processing the audio will undergo before streaming. If we exceed this true peak value, the audio is liable to become distorted during digital processing/conversion.
So when it comes time to set the final limiter on the mix or master bus, be sure to check the true peak level of the audio after the limiter. It's often the case that I'll set the final limiter to a ceiling of -1.2 or -1.1 dBFS in order to hit that -1.0 true peak value.
I have a video on maximizing the loudness of our mixes before mastering for easier referencing outside the studio (against commercially-released songs in different listening environments). Check it out here:
To recap, there are several strategies for avoiding digital clipping to mitigate distortion in our mixes:
- Never exceed 0 dBFS, even in 32-bit floating point systems.
- Don't record too hot in the first place.
- Gain stage properly.
- Ensure the true peak output of the mix/master is at or below the given specs for playback/streaming.
Too Much High-End
An overly distorted-sounding mix could be the result of harshness in the top end of the frequency spectrum. The audio itself may or may not be distorted, but having overly harsh high-end frequencies in the mix can give a sense of distortion.
Overly bright or harsh mixes not only sound bad, but they're all also fatiguing. These characteristics are shared with distorted mixes. To reduce the sense of distortion in a mix, we may only have to reduce the high-end content slightly.
How To Fix/Avoid Harsh High-End
Avoiding or fixing harshness in a mix is often a matter of EQing out some high-frequency content in our tracks, buses or even mix bus.
If a mix sounds overly bright or harsh, I'll typically start by testing an EQ on the mix bus. I'll utilize a high-shelf cut to reduce the top end of the entire mix. If the mix ends up sounding less harsh or distorted, I know I'm on the right track.
While EQing the entire mix is efficient for reducing high-end harshness, I'll generally try to find ways to EQ the individual buses or tracks to bring down the harshness instead. That way, I can rebalance the high-end to have the most important elements well-represented. Of course, if the balance is already perfect, EQing the mix bus can be enough. I just wanted to mention the more intricate strategy of EQing the tracks and subgroups/buses instead.
For more info on using bussing in your mixes, check out my YouTube video here.
Related article: Audio: Buses Vs. Subgroups, Aux Sends/Returns, VCAs & Groups
Another way to reduce high-end harshness while making room for those most important tracks is to use low-pass filters on tracks that don't contribute clean high-end information.
Kick drums mics, electric guitars, bass guitars, and other instruments without notable upper harmonics or brilliance can often be low-passed to make more room for those instruments/tracks that do provide a sense of brilliance in the mix.
As we're mixing and our ears slowly fatigue, it can be tempting to want to increase the brightness of the mix. We can rapidly get accustomed to the current brightness of the mix and begin feeling like a bit more top-end may be necessary. Without using references to keep ourselves in check, this cycle can get out of hand, and we can end up with overly bright and harsh mixes that may border on sounding distorted.
In the moment, we can make ourselves believe that we're improving the mix, only to come back the next day to a harsh, often distorted-sounding mix. For that reason, it's important to regularly refresh our hearing by giving our ears a break, monitoring at lower levels and utilizing reference mixes.
To recap, there are several strategies for avoiding overly bright and harsh mixes that may sound distorted:
- Cut high-end frequencies from the mix.
- Low-pass filter tracks for less competition in the high-end.
- Take frequent breaks to refresh your ears.
For more information on the EQ concepts discussed in this section, check out the following My New Microphone articles:
• Audio Shelving EQ: What Are Low Shelf & High Shelf Filters?
• Audio EQ: What Is A Low-Pass Filter & How Do LPFs Work?
• Complete Guide To Audio Equalization & EQ Hardware/Software
Overcompression, as the name suggests, happens when a compressor acts too aggressively on a signal and effectively squashes the dynamics.
Audio without defined dynamics sounds pretty lifeless. On top of that, overcompression can add a significant amount of distortion to the signal.
If we think of clipping distortion as the “micro,” flattening of the tops and bottom of a waveform, we can think of compression as the “macro,” flattening the loudest parts of the signal overall. We're shaping the waveform with either effect, which is technically distortion.
On top of that, analog compressors and their digital emulations, along with some digital compressors, will colour the signal in addition to compressing it. This can also add to the overall distortion of the mix, though the colour/distortion is often sonically pleasing.
Overcompressing our tracks will kill the dynamics and mush the audio together, often causing a distorted-sounding mix.
How To Fix/Avoid Overcompression
Avoiding poor compression choices, including overcompression, begins with developing a strong sense of the purpose of compression, which ultimately stems from the purpose of mixing: to achieve a proper balance between the tracks of the session.
Mixing is about achieving a proper balance between the tracks of the session.
In terms of the balance of levels, faders are our primary tools. Compression, in a way, can be thought of as automatic fader control: as the audio surpasses a set threshold, the compressor automatically reduces the output level.
In understanding this basic concept, we can better utilize compression to achieve balance and avoid overcompressed, distorted mixes.
Once again, like EQ, another critical strategy for avoiding overcompression is to compress tracks in the context of the mix rather than in solo. The mix is rarely about any single track but rather about how all the tracks work together.
I have a YouTube video on the importance of mixing in the context of the mix rather than in solo. Check it out by clicking here.
But with that said, a great way to avoid overcompression is to utilize a top-down approach, where we begin compressing at the mix bus (top), work our way down to the subgroups/buses, and finally to the individual track if need be.
For more information on subgroups, check out my article What Are Subgroups? (Audio Mixing, Recording, Live Sound).
By compressing the larger buses (being fed by multiple tracks), we can get the “glue” compression, helping bring elements together in the mix while also controlling dynamics. In avoiding compressing every single track, we can avoid the pitfall of overcompressing in serial at each stage/bus a track's audio will pass through.
I have a video dedicated to the subject of top-down mixing. Check it out here:
As with any processing during mixing, it's important to A/B test our compression moves by toggling our compressors on and off to hear whether they actually help the mix or not.
If we find ourselves in a situation where the audio has been overcompressed and then printed (the effect is now part of the audio file), then we might be able to restore transients with a transient shaper or an expander.
Unfortunately, with these efforts, we'll unlikely get anywhere near the original clarity of the signal. However, it's worth trying them in a bind.
To learn more about printing in audio, check out my article What Does “Printing” Mean In Audio Recording/Production?
To recap, there are several strategies to help us fix and avoid overcompression, which can also fix/avoid distorted mixes in certain cases:
- Understand how compression is used for balancing the mix.
- Compress in the context of the mix.
- Use top-down mixing.
- Always A/B test your compressors on and off.
- Focus on the hierarchy of elements in the mix to know which tracks take precedence over others.
- If the compression is printed, try transient shaping or expansion to bring back dynamics.
I have a video where I share my top 11 compression techniques. Check it out here:
Or check out the article: Top 11 Best Compression Tips For Mixing (Overall)
Too Much Limiting
Brickwall limiting (the more common type of limiting in modern mixing) works on the same principle as compression, though at a ratio of ∞:1. In other words, a limiter is designed to not let an audio signal level past a hard set threshold.
Limiting is incredibly useful for maximizing loudness without clipping the mix/master bus. It's also a good tool for controlling the dynamics of tracks and buses before the mix/master bus.
Like compression, over-limiting can suck the life out of music and cause distortion. What's more, is that over-limiting will often cause more issues of distortion than compression since it's a more rigid process, especially if we're over-limiting the entire mix on the mix bus or master bus.
To learn more about buses, check out my article What Are Audio Buses? (Mixing, Recording, Live Sound).
How To Fix/Avoid Over-Limiting
Avoiding over-limiting is similar to avoiding overcompression. Be sure to A/B your choices, and don't drive the limiter too hard.
When A/B testing, it's paramount that level matching is done appropriately (having the same perceived level whether the limiter is on or off). We naturally have a “loudness bias” that all too often convinces us that louder is better, even if it isn't.
In most cases, I aim for about 3 dB of limiting on the transients of the audio and dial in the parameters to taste. Listen critically to how the limiter colours the sound, making sure to A/B test the limiter on/off with level matching, and consider whether less limiting is required or if more can be done before suffering poor results.
Because limiters are designed to stop peaks at a set threshold, they must act fast. Having a fast attack, however, can actually cause waveshaping in longer waveforms (low frequencies). That means that pushing limiters too hard can have a disproportionate effect on bass distortion. This is something else to look out for when limiting the mix bus.
It's generally advisable to set the threshold of the master limiter to -1.1 or -1.2 dB to help ensure the song peaks at -1 dBTP (Decibels True Peak), which may mean reducing the limiter's threshold slightly if it's working hard. This allows some room before 0 dBFS clipping and is necessary to avoid digital distortion when the audio is converted and encoded to most lossy formats.
Beyond that, gaining an extra dB of loudness is sometimes worth it for competing in the loudness wars. However, gaining a bit of extra loudness at the expense of distortion is never worth it, in my opinion.
To recap, there are a few strategies to help us fix and avoid over-limiting that are pretty much the same as those for avoiding overcompression. Here are the two main takeaways:
- Always A/B test your limiters on and off and level match first.
- An extra dB or so of loudness is not worth crushing the mix and causing muffling.
If you're interested, I discuss A/B and my top 5 A/B tests in this short video.
For more information on loudness, check out the following My New Microphone articles:
• The Complete Guide To Louder Mixes (11 Strategies)
• Top 12 Professional Tips To Make Audio Mixes Louder
Distorted mixes can also come as a result of distorted recordings, even if we're following all the technical mixing steps to avoid distortion.
If digital clipping and other unwanted distortion are printed into the audio of the mix tracks, we can try to fix it with de-clipping plugins. However, beyond that, there's not much we can do about this distortion.
The best plan of action, of course, is to get clean recordings to begin with.
Distorted recordings can come as a result of many things, including the following:
- Overloaded microphones.
- Overloaded microphone preamplifiers.
- Overloaded tape.
- Excess noise.
- Faulty cables.
- Faulty instruments.
- Poor/improper analog-to-digital conversion.
How To Fix/Avoid Distorted Recordings
If you're stuck with clipped audio, you can attempt to restore it using a de-clipper plugin.
The Acon Digital Restoration Suite 2 (link to check the price at Plugin Boutique) has a pretty good de-clipper plugin.
But as I stated earlier, the best plan of action is to get clean, unclipped recordings from the get-go.
This means proper using gear in proper working condition, gain staging in any analog equipment, not overloading anything in line, driving any ADCs well below clipping, and keeping a watchful eye over the entire recording process to ensure everything is being recorded clean.
To recap, there are a few strategies to help us fix and avoid distorted recordings and, therefore, distorted mixes:
- Use de-clipper plugins if clipping is printed into the audio.
- Do not use faulty recording gear.
- Gain stage as much as possible to avoid excessive noise during recording.
- Drive analog-to-digital converters well below their specified clipping point to be safe.
- Do not overload any microphones, preamps, instruments, etc.
• What Does A Microphone's Maximum Sound Pressure Level Actually Mean?
Finally, the mix may sound distorted due to the playback system being distorted.
For example, it's relatively common for small smartphone and laptop speakers to distort when pushed to their loudest settings, even if the audio file playing through them isn't distorted itself.
It could also be the case that the media that holds the audio mix is damaged or corrupted.
Examples of distortion in playback systems include:
- Amplifier distortion or amplifier damage (preamp and power amps).
- Overloaded or damaged headphones.
- Overloaded or damaged speakers.
- Improper or damaged cables and connectors.
- Poor digital-to-analog conversion.
Examples of distortion in playback media include:
- Degradation due to lossy formatting conversion.
- Old or damaged tape.
- Old or damaged vinyl.
If we're to find out if our playback system is to blame for distortion, we need to be able to test our audio/mix against references.
If we suspect the playback system is at fault, we should play a few reference tracks we know aren't distorted and hear if the playback system distorts them upon playback.
If we suspect the playback media is at fault, we should, again, play a few reference tracks we know aren't distorted and hear if the playback system distorts them upon playback.
If everything is distorted through the playback system, it's likely something to do with the system. If only our mix is playing back distorted, it could be the file format or physical medium used, or it could be that our mix itself is distorted.
How To Fix/Avoid Distorted Playback
If the playback system is truly the cause of the distortion, we need to spend so time troubleshooting.
Try playing the audio at different levels (higher levels will often distort when lower levels won't). Often, the amplifier or the speaker is the limiting factor here.
But perhaps it's the cables and connectors that are to blame. Try swapping cables and connections if possible to hear if it makes a difference.
If the playback media is the cause of distortion, try bouncing the mix once again and ensure that the file is of high enough quality (lossless is ideal).
To recap, there are a few thoughts I have about solving distortion in playback:
- Troubleshoot the system and the media to try to find the issue.
- Use reference tracks in helping to solve the issue of playback distortion.
• Why Do Speakers Distort At High Sound/Audio Levels?
Why does my mix sound thin, and how can I fix it? Thin-sounding mixes often suffer from thin arrangements or poor recording, to begin with. However, bad EQ choices, phase issues, overly wide stereo images, or a lack of low-end energy, compression, distortion or time-based effects can also cause a thin mix. Finding and addressing each of these issues can solve the issue of thinness in a mix.
Related article: 8 Reasons Your Audio Mixes Sound Thin & How To Fix Them
Why does my mix sound muffled, and how can I fix it? Muffled-sounding mixes are often caused by a lack of high-end energy and over-represented low-end energy, along with poor transient definition and dynamics. Overdoing or incorrect use of compression, EQ, limiting, distortion and time-based effects can contribute to a muffled mix. Fix these issues, and you'll achieve clearer, cleaner mixes.
Related article: 8 Reasons Your Audio Mixes Sound Muffled & How To Fix Them