The basic concept of HiFi appreciation audio

                     The basic concept of HiFi appreciation audio

1. Explanation of terms in electroacoustics

1. Pure tone: It has two meanings: (1) refers to the sound wave whose instantaneous sound pressure changes sinusoidally with time; (2) refers to the sound with a clear single tone.

2. Pitch: Refers to the lowest frequency component in a compound sound.

3. Overtone: The component in the compound sound whose frequency is higher than the pitch, its frequency may be an integral multiple of the pitch frequency, or it may not be. Various musical instruments can produce overtone components with different numbers and strengths by different playing methods, even if the fundamental tone is the same, they can have different timbres.

4. Sound wave: A mechanical wave propagating in an elastic medium, originating from the vibration of a sounding body. The sound wave range is 20Hz-20KHz, and the sound wave with a frequency higher than 20KHz is an ultrasonic wave, and the sound wave with a frequency lower than 20Hz is an infrasonic wave. Ultrasonic waves and infrasonic waves generally cannot cause hearing. Only sound waves with a frequency between the two can be heard. The received sound waves are called sound waves or audible sounds.

5. Sound field: refers to the area in the medium where sound waves exist. Different sound sources and environments can form different sound fields.

6. Loudness: also known as "volume", a feeling of the human ear to the volume. Depends on sound intensity, frequency and waveform.

7. Timbre: Also known as "tone", it is mainly determined by the number of homophonics and the relative amplitude of each homophony.

2. The auditory characteristics of the human ear

The sensitivity of the human ear to the direction, loudness, pitch and timbre of sound is different, and there are large differences.

1. Orientation sense: The human ear has a very strong ability to distinguish the direction, distance and positioning of sound propagation. This auditory characteristic of the human ear is called "orientation sense".

2. Loudness sense: For small sounds, as long as the loudness increases slightly, the human ear can feel it, but when the sound loudness increases to a certain value, even if there is a larger increase, the human ear's perception will not change significantly. Usually, the audible sound is divided into three parts according to the octave relationship to determine the low, middle and high frequency ranges. That is: low frequency range 20Hz-160Hz, middle frequency range 160Hz-2500Hz, high frequency range 2500Hz-20KHz.

3. Timbre sense: refers to the human ear's special auditory comprehensive experience of timbre.

4. Focusing effect: The auditory characteristics of the human ear can focus on a certain point from many sounds. For example, when we listen to a symphony, we focus our energy and hearing on the sound played by the violin, and the music played by other instruments will be suppressed by the cerebral cortex, so that what you hear is the pure sound of the violin. This suppression ability varies from person to person, and people who often do listening exercises have a strong suppression ability. We call this auditory characteristic of the human ear "focus effect". Doing more exercises in this area can improve the ability of the human ear to distinguish the timbre, quality, resolution and level of a certain frequency spectrum.

3. Main technical indicators affecting sound quality and timbre

1. Frequency range (unit Hz): The operating frequency bandwidth of the power amplifier under the specified distortion and rated output power conditions, that is, the range between the lowest operating frequency and the highest operating frequency of the power amplifier.

2. Frequency response (unit: decibel dB): The phenomenon that the output gain of the power amplifier increases or attenuates with the change of the input signal frequency and the phase lag changes with the input signal frequency. This indicator is the most important basis for assessing the quality of the power amplifier. The smaller the decibel value, the flatter the frequency response curve of the power amplifier, the smaller the distortion, and the stronger the signal restoration and reproduction ability. A good set of audio equipment not only reproduces the phonology of various musical instruments, but also reproduces the position, distance and scene of various musical instruments.

Fourth, the meaning of high fidelity

Regardless of your personal preference for tone or model, if the sound played is aurally different from the sound played by the original instrument, it's not a good device. The real meaning of high-fidelity audio (Hi-Fi) is a high degree of reproduction. If your audio equipment cannot restore the timbre of the original instrument, then it cannot be called high-fidelity equipment. When we use subjective hearing to judge a certain audio equipment, we must pay full attention to this point, and do not affect the correct judgment and the improvement of identification ability due to personal preference. If we want to improve our ability to appreciate music, we must listen more and make more comparisons. Each musical instrument has its own unique spectrum and timbre. When a piece of music is played, the timbre emitted by the speaker system is different from the timbre played by the actual instrument, and how much it deviates from it. In order to make a hearing comparison, we should first understand some concepts of acoustic terms, the auditory characteristics of the human ear and the main technical parameters of audio equipment.