Adjustment of the better frequency point of the equalizer

From a statistical point of view, the sound emitted by each sounding body has a certain frequency band (frequency range) and regularity. Only when the frequency range of the sound source is mastered can the sound be balanced and the problems encountered in speech practice can be solved in a targeted manner. If we don’t know the basic range of the voice, it’s like a painter who doesn’t know the color, and it’s impossible to adjust the timbre of the voice. But are all the frequencies included in the frequency range of various sound sources useful for equalization? Music, human voice, and sound effects contain a wide range of frequencies, almost covering the entire range that the human ear can perceive. When using an equalizer, it is impossible for us to boost or attenuate all the frequencies contained in a piece of speech or a piece of music. If this is done, it is equal to increasing and decreasing the volume, and it will not have the effect of equalizing the frequency.

So how to adjust the frequency spectrum state? What frequency can be increased and what frequency should be attenuated? Here we only discuss the issue of adjusting the tone.

 As we have mentioned before, when each lower harmonic has a higher loudness than other harmonics, it will produce its own characteristic influence and change the tone. But the harmonics we want to adjust follow the relative strength of the tone reference line. In the specific control, the sound of a certain segment of voice is real but not virtual, which shows that the components of the low-order harmonics, especially the second harmonic, are stronger. If you adjust the tone again, you can balance the proportions of the harmonics according to your needs. If you want to make the sound thicker and stronger, you can increase the 4th, 5th, and 6th harmonics; if you want to make the sound brighter, you can The 10th harmonic is increased a bit, and the above frequencies will attenuate the level as the frequency increases. As long as they basically conform to the tone color reference line, the deep attenuation of the 10th and above harmonics will work. Another example: the sound of a certain musical instrument is false but not real, which shows that the components of the 1st and 2nd harmonics are weak and the amplitude is small. At this time, the timbre adjustment should compensate the gain of the 1st and 2nd harmonics. If the sound is still noisy, it means that the amplitude of the high-frequency range is too large or even exceeds the tone reference line. The attenuation of other frequencies should be considered. When the frequency is equalized, if you only use increase instead of decrease, only It is absolutely undesirable to increase the chance of distortion.

In the operation of using the EQ in COOL EDIT, we can immediately determine what frequency should be adjusted based on the analysis of the tone. In fact, they first consider the main resonance center frequency of the sound source tone, and then modify it. Some minor harmonics are used to achieve frequency equalization. This includes the correct evaluation of timbre and a good grasp of frequency characteristics. Let me introduce some experience to everyone.

 (1) Listen to determine your evaluation of the sound. Of course, it is necessary to understand the correct tone of the sound source, otherwise it will not be targeted.

(2) Decide which frequency to adjust according to the subjective evaluation of hearing perception, that is, determine the rough frequency adjustment range.

(3) Turn the gain of this equalization to a large value to make it easy to listen to.

(4) Try to use this frequency and nearby frequencies to gradually narrow the frequency range. When it is confirmed that the tone of a certain frequency point meets the adjustment intention, the frequency or frequency is determined.

(5) Reduce the frequency gain of this section, and determine the loudness when the auditory frequency equalization ratio is appropriate.

(6) Listen carefully again to confirm whether other frequency bands need to be adjusted until you are satisfied.

Of course, this method is also suitable for attenuating a certain frequency. Set the gain knob to a large attenuation value. When scanning this section of frequencies, which frequency is effective for the amount of sound to be attenuated, the appropriate attenuation frequency point is found.

Since speech (which should include all sounds) is a composite tone, and contains many characteristics that need to be characterized, according to Fourier analysis. In this way, when we perform equalization, we can consider the timbre characteristics as a whole according to the relationship between the fundamental wave and the harmonics and try to reflect the whole picture as much as possible. Therefore, when performing the frequency equalization of a certain segment of speech, it cannot be effective by increasing or decreasing the single-point frequency. In other words, it needs to be processed separately at each frequency, and only by giving full play to the coordination effect of each frequency in the full audio range, can the voice tone of this segment meet its own requirements.

 In the frequency domain of a music program, each frequency band has its own independent function. The increase or attenuation of each frequency will change the content of the music. Below we divide the full audio into six segments for specific analysis:

(1) The frequency range of 16~80HZ (super bass) can bring a strong feeling to music, especially the frequency below 20Hz, which can strengthen the sense of air vibration, and excessive increase will make the sound muddy. But in the process of replaying our voice, this frequency cannot be replayed generally.

(2) The frequency range of 80 to 250 Hz (bass) contains the basic sound of each part of the voice. The adjustment of this frequency can change the balance of the music, making it tend to be full or thin. Too much increase will cause "Rumble" sound (low frequency hum RUMBLE). In order to enhance the fullness of some instruments with weak sound power, in the process of human voice processing, the frequency of bass can usually be lowered to below 100Hz, but when the frequency below 100Hz is cut, low-frequency noise can be eliminated, making the sound more Pure. When the frequency of 100-160Hz is long, the human voice will be low and dull.

(3) The frequency range from 250HZ to 2KHZ (midrange) contains the low-order harmonics of most parts, and 250-500Hz affects the strength and firmness of the tone. 330HZ gives the vocal solidity and makes the bass soft and full. But too much improvement will produce a "buzzing" bathroom effect. More than 500 to 800 will make the sound blunt. If you add a wide boost peak in the 800Hz-2KHz range, you can make the sound more prominent. The center frequency gain should generally not exceed 8dB. When 500Hz is increased too much, it will produce cone sound quality, and it is also used in attenuation state during use. When 1~2KHz is increased too much, it will produce a tone similar to iron sound. The tone of the telephone.