Voice equalization:
Your vocal tone needs to be as natural sounding and articulate as possible. Avoid relying solely on what other hams may think of your audio as they will often disagree with what constitutes ideal-sounding transmit audio. So, develop your own style while avoiding unpolished or harsh-sounding audio that will likely annoy and distract your listeners. Always be mindful to not interfere with hams on adjacent frequencies.
Often misunderstood by Hams, equalizers (EQ) should only be used judiciously to achieve improved transmit audio reinforcement. As such, knowing how to properly EQ your transmitted audio is one of the most critical tasks to master. From correcting problems and enhancing your sound to adding cohesion to your voice, there’s a lot you can accomplish with proper equalization. Excessive EQing should be avoided! Don't ruin your otherwise great-sounding voice and microphone with heavy-handed EQing! Concentrate on achieving great-sounding audio at the source, and you will achieve far better results. This means choosing a high-quality microphone, minimizing shack noise, and employing the proper microphone technique. As such, understanding how to use it to your advantage can greatly enhance your sound. Learn to "work your mic by adhering to these techniques:
1. The placement of the microphone, relative to your mouth, plays a large role in the clarity and character of your voice. Experiment with mic placement. A good starting point is 3 - 5 inches.
2. Avoid lateral movements to either side of the microphone. Generally, it is necessary to remain "on-axis" (in front of the microphone) to ensure a clear tone.
3. It is preferable to remain the same distance from the microphone to ensure a consistent volume.
4. Consider the proximity effect whereby base sounding tones are enhanced by "close talking" a directional microphone, the type most hams use. Be careful doing this as it may make you more prone to "popping your Ps" when a burst of air from your mouth overloads and distorts the microphone. Popping occurs mostly on "plosives" (words that begin with "p," "b," and "t.") A windscreen or pop filter is a useful deterrent.
Follow these techniques, and you will sound better and appear more experienced. While equalization can do wonders, it’s important to consider the bigger picture every time you reach for the EQ. An equalizer (EQ) is a filter that allows you to adjust the level of a frequency, or range of frequencies, of a human voice audio signal. In its simplest form, an EQ will let you turn the treble and bass up or down, allowing you to adjust the coloration of your transmit or receive audio. Equalization is a sophisticated art. Good equalization is something to strive for. Parametric EQ The parametric EQ is the most common equalizer found because it offers continuous control over all parameters. A parametric EQ offers continuous control over the audio signal’s frequency content, which is divided into several bands of frequencies (most commonly three to seven bands). A fully parametric EQ offers control over the bandwidth (basically, the range of frequencies affected), the center frequency of the band, and the level (boost/cut) of the designated frequency band. It also offers separate control over the Q, which is the ratio of the center frequency to the bandwidth. A semi-parametric EQ provides control over most of these parameters but the Q is fixed. Q is the ratio of the center frequency to bandwidth, and if the center frequency is fixed, then bandwidth is inversely proportional to Q—meaning that as you raise the Q, you narrow the bandwidth. In fully parametric EQs, you have continuous bandwidth control and/or continuous Q control, which allows you to attenuate or boost a very narrow or wide range of frequencies. A narrow bandwidth (higher Q) has obvious benefits for removing unpleasant tones. Let’s say you have a particularly annoying nasal quality to your audio. With a very narrow bandwidth, you can isolate this one frequency (usually around 650) and remove, or reject, it. This type of narrowband-reject filter is also known as a notch filter. By notching out the offending frequency, you can remove the problem without removing the instrument from the mix. Narrow bandwidth is also useful in boosting pleasant tones as well. A broad bandwidth accentuates or attenuates a larger band of frequencies. The broad and narrow bandwidths (high and low Q) are usually used in conjunction with one another to achieve the desired effect. A shelving EQ attenuates or boosts frequencies above or below a specified cutoff point. Shelving equalizers come in two different varieties: high-pass and low-pass. Low-pass shelving filters pass all frequencies below the specified cutoff frequency while attenuating all the frequencies above it. A high-pass filter does the opposite: passing all frequencies above the specified cut-off frequency while attenuating everything below.Note: Once popular graphic EQs use sliders to adjust the amplitude for each frequency band. K4QKY does not recommend their use in audio processing.
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Low frequency (200–500Hz)
This frequency range is where muddiness often lives, but it’s also where the warmth of your voice originates. If your audio sounds mushy, try cutting low frequencies in this range. If your vocals are clear but lack warmth, try minimal boosting in this range.
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Midrange (1-1.5kHz)
Almost universally, 1-3kHz is where nasal and other troublesome frequencies lie. Try cutting somewhere within this frequency range. More about the importance of surgical cutting in the midrange is discussed later on this site.
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High frequency (1.5 to 3kHz)
Articulation resides here but be careful boosting too much as this can render your vocals harsh and jarring.
EQ with Your Ears
Compression
Do we need compression for voice processing?
Yes, but sparingly. Compression can be beneficial to reduce (compress) the dynamic range of your voice. At a proper adjustment, lower-level word phrases will rise toward already louder phrases improving the ability of your transmit audio to “sit higher above the existing band noise” with greater presence. Avoid over-compression. A properly adjusted compressor should never be obvious to other hams!
Noise Gate
Do we also need a noise gate?
Yes, unless you are fortunate enough to have a quiet shack. Problems sometimes arise when shack background noise (air conditioner, linear amp fan, etc.) becomes more audible after the lower end of the dynamic range is raised. This calls for the use of a noise gate. The noise-gate threshold could be set at the bottom of the dynamic range of the vocal, say -10 dBu, such that the gate would shut out the unwanted signals between spoken phrases. Be mindful to minimize the sensitivity of your microphone in picking up unwanted shack noise. K4QKY always uses microphones with a cardioid pickup pattern, correct microphone output setting, and speaks about 3 inches into his microphone.
What is noise gating?
Noise gating is the process of removing unwanted sounds from a signal by attenuating all signals below a set threshold. As described, the gate works independently of the audio signal after being “triggered” by the signal crossing the gate threshold. The gate will remain open as long as the signal is above the threshold. How fast the gate opens to let the “good” signal through is determined by the attack time. How long the gate stays open after the signal has gone below the threshold is determined by the hold time. How fast the gate closes is determined by the release. How much the gate attenuates the unwanted signal while closed is determined by the range.
Noise gates were originally designed to help eliminate extraneous noise and unwanted artifacts from a recording, such as a hiss, rumble, or transients from other instruments in the room. Since hiss and noise are not as loud as the instrument being recorded, a properly set gate will only allow the intended sound to pass through; the volume of everything else is lowered. Not only will this strip away unwanted artifacts like hiss, but it will also add definition and clarity to the desired sound. This is a very popular application for noise gates, especially with percussion instruments, as it will add punch or “tighten” the percussive sound and make it more pronounced.
What else is necessary?
Nothing really, until such time you're ready to experiment with more advanced processing techniques.
...The remainder of this article provides a setup guide for a software-based digital audio workstation (DAW) as an effective alternative to conventional hardware-based sound processing techniques.