Video quality is important, but bad audio will have viewers clicking the back button faster than you can say, “Please like and subscribe.” By using two basic audio tools—the equalizer and the compressor—you can quickly correct problems with your voiceover recordings and give your videos a professional sound. In this article, we’ll teach you how to improve sound quality of a recorded video using EQ and compression. First, let’s talk about know how to use an equalizer.
How to Use an Equalizer
Use EQ to boost or reduce certain frequency ranges to achieve a clearer, more balanced sound.
The human voice produces a complex blend of low-frequency sounds (typically vowels) and high-frequency sounds (usually consonants), which need to be properly balanced. Using a parametric equalizer or graphic equalizer that can be found in almost any software, you can boost or reduce certain frequency ranges to achieve a clearer, more balanced sound.
Everyone’s voice is unique like a fingerprint, which makes it important to custom-tune EQ settings to each person’s voice. There may not be a one-size-fits-all solution, but here are some of the best equalizer settings and processes to get you started.
Use a high pass filter to cut off everything below 80 Hz. The human voice typically begins around 100 Hz, so we can filter out everything below that to minimize rumble from nearby traffic and footsteps.
100 Hz – 250 Hz: The fundamentals of the human voice lie in this range. Male voices on average tend to be closer to 100 Hz, while female voices tend to register closer to 200 Hz; however, every voice is unique. You can boost this range by 3-6 dB if a voice is lacking warmth, or reduce in this range if it sounds too boomy.
250 Hz – 1 kHz: Many overtones of the human voice can be found in this range. Boosting here can make the voice sound richer. Alternatively, you can cut in the 250 – 500 Hz range if your voice sounds too muddy. Also, be careful around 1 kHz… boost too much here and you risk sounding annoyingly nasal. Start with a couple dB and add more as needed.
1 kHz – 8 kHz: Most consonants reside here; therefore this range is extremely important for intelligibility. To ensure clarity in your voiceover, try boosting by about 3 dB between 2 kHz – 6 kHz for male voices and 4 kHz – 8 kHz for female voices. This is also a good place to look for a cut if your voice is coming across too shrill or harsh.
8 kHz – 20 kHz: As you get higher in the frequency range above 8 kHz, you have to be very careful to keep your audio sounding smooth. A 1-2 dB boost here can make your vocal sound more airy, while a small dip can keep your vocal sounding warm.
Don’t be afraid to experiment with your EQ settings until you’ve dialed in a natural-sounding voiceover.
How to Use a Compressor
Use compression to even out the quietest and loudest parts of your recording for a more consistent vocal level.
By now, your voice should sound clearer and richer, but may still be uneven in volume. Perhaps it’s too quiet to understand what you’re saying in some places, and then spikes in others. To balance the quietest parts of your signal with the loudest parts, you’re going to need a compressor.
So what does a compressor do? A compressor is a leveling amplifier that boosts sounds below a certain threshold, while turning down (or compressing) sounds that occur over the threshold. In order to understand how to use a compressor, let’s take a look at the basic controls.
Compression Threshold: This is the level at which compression begins. When the signal crosses this threshold, the compressor clamps down on the peaks to even out the dynamics. Set this at zero and slowly bring the threshold down until you see your gain reduction meter bouncing regularly.
Compression Ratio: This knob determines the ratio of compression that happens when the signal passes the threshold. A higher setting results in more compression, while a lower setting results in less. For voice, you can set your ratio between 2:1 and 3:1 dB for smooth, gentle compression.
Attack and Release: The “attack” and “release” settings affect how quickly the compression turns on and turns off. A slower attack time allows peaks through before compressing, while faster attack times will clamp down quickly before the transient burst can get through. Try setting your attack time between 3 – 10 milliseconds to get the most smoothing while keeping your voice sounding natural.
Now set your release time so that the compressor quickly recovers when a signal falls below the threshold, but can’t be heard “pumping.” This could be as fast as 10 – 15 milliseconds or as slow as 30 – 40 milliseconds.
After you’ve applied this technique to your voiceover, you can use the “makeup gain” knob to optimize the overall signal level now that the peaks have been taken care of. In most circumstances, you may find you can boost around +5 dB to get a “loud and clear” balanced sound.
Now that you know how to improve sound quality of a recorded video using EQ and compression, you can even go back and sweeten some of your old videos for better audio quality!