What are the related technologies of sound?

High, medium and low frequencies
20 - 40 Hz very low frequency, can reach this range of instruments are very few, and this range of sound has no direction, is the most difficult to express the range of sound equipment. Low frequencies of 40 - 80 Hz increase by an octave (an octave for every doubling or decreasing frequency). 80 - 160 Hz medium and low frequency, an additional eight degrees. This frequency band is the most easily generated room standing wave band. From 160 to 1280 Hz, it spans three octaves (320 Hz, 640 Hz, 1280 Hz), which is the most frequent frequency of all instruments and voices, and also the soul of music. 1280 - 2560 Hz medium and high frequency, is also increased by an octave. Most of the two-way speakers set the frequency division point at 2500-3000Hz. The upward frequency is handed over to the tweeter (high frequency, very high frequency), while the downward frequency is handled by another medium-low unit, which is the broad frequency band below the middle-high frequency. 2560 - 5120 Hz high frequency, so far, almost all instruments can play the "pitch" pitch has been cut off, we use the performance of instruments to distinguish the high and low frequency band method so far. All that is heard above 5120 Hz is the overtone of the instrument. The pitch is given a fixed pitch, while overtone is the source of the different timbres of the instrument. In this very high frequency overtone range, no one can judge 8000 Hz or 16000 Hz by the pitch played by an instrument (unless the pitch is produced by a signal generator, but that has nothing to do with music). However, the frequency above 5120 Hz is the main reason for the adjectives such as "sweet voice", "lustrous strings" and "full transparency". When describing music, such adjectives as "not transparent enough", "not lustrous enough", "rough and sharp", they represent "very high frequency deficiency". That's why I advocate an extra pair of super-high-pitch units for my enthusiasts and friends. It's also one of the indispensable elements of the "noble spirit" of sound. Aren't some of the technical words mentioned in this passage indispensable for listening to music? The simplest way to remember the digital relationship between scale and frequency is to use the central A as the standard (i.e. La) and the central A as 440 Hz. The next octave of A is 220 Hz and the next octave is 110 Hz. And upwards, 880 Hz, 1760 and so on are very memorable. This is why a sound commentator can easily point out that an instrument is playing at a pitch of several Hz.

Sound field
When a speaker makes a sound in a room, the listener can hear the sound coming directly from the speaker, which is the indirect field, but also the sound reflected from the wall, ceiling and floor, which is called the reverberant field. The more direct sound the listener hears, the smaller the sound of the reflected sound field is, the better the sound is. Because the sound of the direct sound field can be controlled, but the sound of the reflected sound field can not be controlled. It only adds noise to the sound produced by the direct stadium and reduces the clarity of the original sound, so the listener sitting closer to the speaker will feel better. Point sound effect, and the audience sitting behind is likely to hear the reflected sound field louder than the direct sound field, the sound effect will be worse and the clarity will be reduced. Sometimes when a band is performing on stage, because they do not monitor the speakers, and the main speakers on both sides are located near the entrance of the stage. The voices heard by the band and the singer are not played from the direct sound field at all. Their standing position is called the indirect sound field. Of course, the sound effect will not be good, which will also affect the performance level of the band and make the audience not hear well. Performing sound.


Interface interference
When we choose the location of the speaker, it is important to note that the sound emitted by the speaker will be disturbed by the interface beside it. For example, in the main speakers on both sides of the desk, when their bass basins leave the ground and the wall next to them, if it is about 1 meter, a 4-meter-wavelength audio will be disturbed by these two interfaces. A 4-meter wavelength frequency is 86 Hz (344 m/s_4 m= 86 Hz). When the sound of 86HZ comes out of the speaker, the high air pressure happens to bump into the ground and wall within 1/4 weeks, and then reflects back to the speaker's carton in front of it in 1/4 weeks. But at this time, the carton will retreat, and the large air pressure reflected from the ground and wall will be offset by the carton's retreat. Causing the loss of a very important bass. If this happens, the speaker should be retreated 0.5-1 meters so that the sound emitted by the speaker can not be directly projected to the ground, and if the speaker can be moved to the walls near both sides, the reflection of the wall can be used to make greater volume. The frequency of 80-100Hz is very important. It is the resonance point of our lung space and the resonance frequency of the bass drum. It is not worth it if the speaker is misplaced due to the lack of understanding of the interface interference.


High and Bass Effect
It is difficult to specify a high frequency or a low frequency. We often say that people's hearing is from 20Hh to 20KHz, but the frequency of 20kHz is rarely heard by people. Usually only young people under 20 years old can hear it without any damage to their ears. If you take an auditory test, the highest frequency is only 8 kHz. When sound is transmitted out, the high frequency attenuates much faster than the low frequency, if 1 kHz and 10 kHz are used.