Clipping is one of the most frustrating technical issues when recording audio. Avoiding clipping is not easy because there are so many points in the recording process that can cause the problem. Isolating the cause, or ideally, setting up your equipment to prevent it in the first place, can be a confusing process.
Here are 9 ways to avoid (or repair) clipping when recording vocals:
- Use a pop filter on your mic.
- Switch to a less sensitive mic.
- Run a sound check before recording.
- Record a backup track.
- Record loud and soft vocals separately.
- Record vocals through a compressor.
- Normalize audio tracks.
- Use gain staging to configure equipment.
- Use audio repair software.
Why clipping occurs, why it’s a problem, and how to avoid it can be challenging questions even for experienced recording professionals. This article will help you understand clipping and how to keep it from ruining your vocal recordings.
What Is Clipping?
Simply put, clipping happens when your audio signal pushes your recording setup past its maximum limits. If you look at the waveforms in an editor, you’ll see the sound waves appear to be sheared off at their tops, making them look like flat plateaus.
When you listen to the track, it’ll sound distorted, sometimes sounding scratchy or crackly, or like parts of the sound are missing. Watch this YouTube video for an excellent example of what clipping sounds like:
Sound clipping can happen at any stage of your digital or analog recording, from your microphone preamp to your mixer and audio interface to your computer’s digital audio workstation (DAW). Wherever the audio signal is amplified beyond maximum limits, the distortion will be passed down the line.
Clipping can be tough to catch and even tougher to diagnose because multiple points in any recording setup allow you to set input/output levels. You might increase your levels on one instrument or device because the audio doesn’t sound loud enough, not realizing that you’re passing too much signal down the line.
Gain vs. Volume
Before we move forward, let’s clarify the difference between gain and volume. The terms are often used interchangeably, and getting them confused can often be the root cause of clipping issues.
Basically, gain controls the loudness of audio going into your recording system (for instance, your preamp, amplifier, or audio interface), while volume controls the loudness of audio coming out the other end after processing. In other words, volume is how loud the audio sounds to your ears, while gain is the amount of signal going into the recording.
This distinction is crucial because level settings based simply on how loud the audio sounds may be totally inaccurate. An excellent example of this concept is playing music on a computer connected to speakers. You play a song on your audio app with your speaker volume turned down and the app’s volume control cranked up as high as it’ll go. Even though the sound coming from your speakers is quiet, the song still sounds distorted.
This example illustrates how confusing gain and volume can lead to clipped sound. Let’s say you’re recording audio from your mic into your audio editor, monitoring it through headphones plugged into your computer.
The audio sounds too quiet through your headphones, so you dial up the gain on your app. Only, you’ve forgotten that your headphone volume is set very low, and that’s why the audio seems too quiet. The end result? Clipping.
Why Should I Care About Audio Clipping?
Aside from the obvious problem of your recording sounding terrible (unless you’re deliberately trying to achieve a distorted effect, like in a heavy metal guitar track), clipping from setting gain too high can potentially damage your equipment.
Going back to the definition of gain as how much signal is going into your recording system, that signal is electricity measured in voltage units (VU). Higher voltage means higher temperatures.
For speakers, overheating can cause damage to coils, and jarring woofer vibrations can tear the fabric on the cone. Far less likely but still possible is damage to components of your amplifier from too much input voltage.
So, while these are extreme circumstances and it’s unlikely that you’re going to fry any equipment while, say, recording a podcast, it’s all the more reason to take care to avoid excessive gain input.
Why My Vocals Are Clipping
As I mentioned earlier, clipping can happen anywhere along the recording signal flow. Depending on your setup, any of these factors could be the culprit:
- Your microphone gain, through either a built-in or external preamplifier, could be set too high for your vocal.
- Analog clipping can also occur through an amplifier, instrument, mixer, or analog-to-digital converter.
- Digital clipping can be caused by a digital-to-analog converter or in any software during editing and mastering.
Clipping happens because somewhere along the line, the amount of signal being allowed into the system is greater than it can handle.
How Can I Tell if There Is Clipping?
The simplest way to tell if your vocal recording is clipping is by keeping an eye on your recording device or app. Most recording devices have a volume meter that will indicate that the gain is too high by the needle being in the red or a flashing red light. In your DAW, watch the audio waveforms.
Too high of a level, and you’ll see the waveforms flattening out at the upper or lower edges of the track. Some apps also indicate signal limits with red lines or warn of clipping by highlighting the waveforms in red.
How To Avoid Clipping When Recording Vocals
You can reduce the risk of distorted audio with equipment, recording techniques, and editing processes. Even if you don’t discover the clipping until it’s too late, it may be possible to improve the sound with audio repair software.
Use a Pop Filter
You see pop filters all the time in photos and videos of recording sessions–they’re the discs of black fabric attached to the microphone stand. Placed between your mouth and the mic, pop filters eliminate plosives, or the “popping” sounds that vocalists can make when speaking or singing into the microphone.
Words with plosive sounds have letters like “t,” “p,” or “b” in them (as in “tornado,” “people,” or “bartender”) that, when spoken or sung, send bursts of air toward the mic. Those bursts create audio spikes, which may be large enough to be clipped. Pop filters dissipate those bursts of air, scattering them enough to be harmless to the recording.
If you’re prone to loud plosive sounds–and most of us are–attaching a pop filter to the mic can eliminate many clipping occurrences at the source. If you don’t have a pop filter handy, you can minimize the effect of plosives by putting some extra distance between yourself and the mic.
Use a Dynamic Microphone
Clipping often occurs if your vocals are loud for the type of microphone you’re using. Condenser mics, usually found in recording studios, are typically great for vocals because their high sensitivity can capture delicate nuances.
If you’re recording a particularly booming voice, however, and you’re not using a preamp to limit microphone gain, try switching to a dynamic mic. Typically used to record loud sounds or live performances, their lower sensitivity won’t send out as much audio signal.
Do Sound Checks
One common technique for avoiding clipping is running a sound check before recording. During the sound check, perform the vocal a little louder than you will when recording and set your gain levels accordingly. This will allow you more headroom (or margin of safety) in case you end up speaking or singing more loudly than anticipated.
Record Backup Tracks
Another approach that can anticipate potential vocal performance issues is to record a backup track in addition to your main recording, each set to different input levels. Set your primary track to your normal peak gain levels and your backup track a little lower. When editing the session, you can replace any sections with clipping on the main track with sections from your backup.
Record Separate Tracks
Suppose your vocals will be a combination of very loud and very soft sounds. In that case, one possible strategy is to record each part separately, with gain levels set accordingly, and mix the elements together in editing.
Of course, this method may not be practical for your project. For instance, if you’re recording an impromptu conversation or monologue, it won’t be possible to know what the loud moments will be.
In that case, you can lean back from the mic when raising your voice (and ask your guests to do the same). Or, if you’re anticipating a boisterous vocal performance, set your gain levels lower than peak and expect to make adjustments later.
Use a Compressor
Whether it’s the software compressor tool in your recording/editing app or an analog hardware compressor, compression reduces the overall dynamic range of your recording. Dynamic range is the area between the loudest and quietest parts of your recording.
A compressor makes the loud parts softer and the soft parts louder, preventing clipping by keeping the audio signal from exceeding the dynamic range.
However, you’ll need to find the right amount of compression to achieve your desired audio quality. Too much, and your vocals will come out sounding unnaturally thick and dull while capturing too much background noise. Too little compression, and your voice will sound faint and thin, and the sound will be significantly quieter overall.
Normalize Your Tracks
In its simplest form, normalization is a recording and editing technique that raises the overall volume of audio input to a target level (typically just below the top of your dynamic range). It’s often used for projects that require a standard, consistent volume, like podcasts or audiobooks.
Normalization can be a helpful tool since it will automatically boost the volume of quiet moments without boosting louder moments to the point of clipping. Some audio apps can be set to normalize audio while recording, or you can use this process in post-production.
Be aware, though, that normalization is usually a destructive process, meaning that it will permanently alter the audio file (although most programs do allow you to undo the process). If you plan to experiment with normalizing audio, be sure to back up your original files beforehand.
Gain staging is the best overall strategy for avoiding clipping during the recording process and a critical step in achieving professional-sounding audio. It sounds complicated and can overwhelm beginners, but it’s worth learning.
What Is Gain Staging?
Gain staging is simply the process of making your sound level consistent throughout your entire recording system. A gain stage is a point where you can control the amplitude, or loudness, of your audio signal. With gain staging, you adjust your gain stages for maximum quality.
Examples of Gain Stages
Your gain stages will depend on your recording setup, but a basic signal chain–the order in which sound flows through your project–might include:
- The audio source, which can be a vocalist
- A microphone and mic preamp
- An audio interface to convert your signal from analog to digital before going to your computer
- The DAW software, including any plugins that might affect gain levels
- The audio output from your computer
- The audio interface that changes your digital signal back to analog
- The speakers or headphones
Adjusting Your Gain Stages
The goal of gain staging is to adjust your equipment so that every link in the signal chain works in harmony. Every piece of equipment has an ideal volume range it’s intended to operate within.
Let’s pause for a moment to review the units for the settings you’ll be working with.
- For digital equipment, decibels (dB), or loudness levels, are measured in units of dBFS (digital full scale).
- For analog equipment, decibels are measured in dBu (decibels unloaded).
- The electrical power going through the system is measured in VU (voltage units).
A helpful rule of thumb to estimate equivalent digital and audio settings is this equation: 0 dBu = -18 dBFS.
Another bit of terminology that you should be familiar with is the noise floor. The noise floor is basically the background noise in a recording, the sound you hear when no other audio is recorded, like the hum from a microphone or ambient noises. This is the base level of your recording. It’s essential to keep your noise floor low so you don’t have extraneous sounds muddying your audio.
When setting your input gain levels, the goal is a signal that’s louder than the noise floor but not so loud as to produce clipping. You also want to provide some headroom– the space between the loudest part of your track and the upper limit of your dynamic range.
The ideal level for all gain stages is 0 dBU or -18 dBFS. To keep your recording within the sweet spot between too low, where you get interference from your noise floor, and too high, where the dreaded clipping occurs, keep your peaks around -10 dBFS and maintain an average level of -18 dBFS.
How To Fix Clipping in Recorded Audio
If the worst comes to worst, you discover clipping in your audio tracks, and it’s too late to re-record them, it may still be possible to salvage your project in post-production.
Most DAWs include features that can help repair or at least smooth over areas of clipping. For instance, the popular editing app Audacity has a Clip Fix tool that can reconstruct damaged waveforms. Adobe Premiere Pro and Audition offer a similar DeClipper tool.
Plugins are also available for DAWs that provide even more robust audio repair tools. A few popular examples include:
- Accusonus De-clipper
- Antares Soundsoap 5
- Sonnox Oxford DeNoiser
- Waves WNS Noise Suppressor
- Waves X-Noise
The distortion from clipping can ruin your vocal track and your entire project. You can avoid clipping when recording vocals or reduce the damage if it’s too late by employing these strategies:
- Make sure you have the right equipment.
- Use recording strategies and tools to minimize potential problems.
- Configure your devices to ensure quality sound.
- Use post-processing techniques to repair damage.
- YouTube: Clipping Example
- Ledger Note: Gain vs Volume: The Practical Differences That Matter
- Izotope: How to Avoid Audio Clipping When Recording Dynamic Vocals
- Recording Voice: How Do I Stop My Mic from Clipping
- Musician’s HQ: What dB Should Vocals Be Recorded at and Why?
- Ledger Note: Gain Staging: Levels Are Everything for High-Resolution Recordings
- Gemtracks: What Is Audio Clipping and How to Fix It Quickly
- Audacity: Free, Open Source, Cross-Platform Audio Software
- Adobe: Premiere Pro
- Adobe: Audition
- Accusonus: De-clipper Plugin: Salvage Tracks Which Cannot Be Recorded Again
- Antares: Soundsoap 5
- Sonnox: Oxford DeNoiser
- Waves: WNS Noise Suppressor
- Waves: X-Noise
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