In this article we share several methods of addressing the plosives which can occur in voice and vocal recordings.
Low-end plosive thumps can spoil vocal recordings fast. Plosives are common when vocalists or voice-over artists pronounce P or B consonants which hit the diaphragm of the microphone. The results are rarely desired, as you can hear in the following audio example.
Each of the examples below were recorded with the microphone set at the same distance.
There are a handful of simple and proven means of reducing plosives at the front end of tracking:
1. Pop Shields
Also known as popper stoppers and pop filters, pop shields are simple clip-on devices based around either fabric or metal grill designs which position between a talent's mouth and microphone. Their purpose is attenuates low-end plosive energy before sound has the chance of hitting a microphone's diaphragm.
Listen to the audio example below to hear the same dialog line recorded with a popper stopper in place.
There is no doubt that popper stoppers work exceptionally well at reducing plosive effects in controlled recording studio environments, but there are times when an engineer either prefers not to use one or has no option to record with one. Some examples include:
Talent doesn't feel comfortable performing with a pop shield in their face
The pop shield obstructs the talent's view of lyrics
The pop shield blocks the performer's face in the filming of a live recording of a performance
The talent used a handheld dynamic microphone in the recording of a live performance
2. Microphone Off-axis
Another simple way to reduce plosive effects if you don’t use a pop shield is to angle the microphone slightly off-axis. The vocal tone may change a little but if you either have no available pop shield or you choose not to use one, this method works well as it lets the plosive’s burst of air from the talent’s mouth pass away from the diaphragm of a microphone.
Hear our example below to hear this method in action.
3. Wind Shield
Some microphones, such as the AKG C414 large-diaphragm condenser used for recording these audio examples, include foam windshields. Many believe these types of shields also reduce plosives, which isn’t always the case. The C414 windshield is incredibly thin, only really capable of reducing very low levels of wind noise.
The following example was recorded on-axis with the foam windshield from a Shure SM7b dynamic over the C414. The foam from the SM7b is much thicker and denser which produced impressive levels of plosive reduction as you can hear in the example below.
How To Reduce Plosives In A Mix
There are several relatively simple ways you can tackle plosives in post production using stock plug-ins in your DAW and plug-ins designed specifically for plosive reduction. Below are several solutions you can experiment with if plosives threaten to derail your vocal mix.
High Pass Filters & Low Shelf EQ
High pass filters or low shelf EQ are two simple ways to quickly remedy plosives as they simply roll off low end in which plosives reside. A 100Hz 72dB per octave roll off with a high pass filter is a good starting point but you should bear in mind you may also weaken the tone of the vocal in the process so it’s important to find the best frequency. EQ won’t fix really bad plosive pops though.
In some cases you may find that spot edits will help maintain the overall tone of your recording while reducing plosives. Automation could be used to kick in only where plosives are present, or you could commit EQ processing directly to the areas within the audio waveform itself.
Dynamic EQ
Dynamic EQ can also work well at reducing pesky plosives and be set quickly with an analyser. The results maintain a consistent vocal tone in sections where plosives are not an issue only to attenuate them when a dynamic band’s threshold has triggered.
Third Party Plug-ins For Reducing Plosives In Voice And Vocal Recordings
Below are two simple to use third-party plug-ins designed specifically for dealing with plosive content in vocal recordings. We’ve included examples of each for you to listen to and compare the results of.
Accusonus ERA Plosive Remover
Accusonus ERA Plosive Remover provides two main processing modes to help you tackle subtle to extreme plosives along with a helpful real-time processing display which shows when the automatic reduction kicks in. Like other ERA plug-ins by Accusonus, the single central processing dial does all the heavy lifting which is great if your mixing against the clock.
ERA Plosive Remover is available in both the ERA 4 Standard and Pro Bundles and can be purchased separately for $59.
iZotope RX De-Plosive Module
iZotope’s De-Plosive module in RX 7 also quickly remove plosives that can occur during a recording. Like Accusonus ERA, De-Plosive also intelligently detects plosive and reduces them fast with a few minor adjustments to the controls. Sadly, De-Plosive is only available as part of RX.
Honourable Mention: Oeksound soothe2
Oeksound soothe2 is a dynamics resonance suppressor which in version 2 got the ability to work across the entire range of human hearing whereas the original targeted mid to high resonances above 250Hz. This new extended range means we can now use soothe's powers to address mud or excessive weight in the low end. We decided to try soothe2 on our plosive example. It did a good job but missed the extreme low end plosive effect towards the end of the dialog line.
Which Is Best?
There’s no doubt that the best way to eliminate plosives is to use a pop shield in tracking stages. In post production, the best way to reduce plosives is to find a workflow that best suits your style, of which we’ve covered in this article.
I use Accusonus ERA in the plug-in chain I use for processing my Production Expert video voice-overs. There are times when it isn’t appropriate for me to use a pop shield as it often obscures my computer display which I need a clear line of sight of when producing screen cap videos. The reason why I love using ERA is that it’s very much a set-it-and-forget-it tool. In most cases just enabling ERA does exactly what I need it to do.