First, the headset is how to classify it?
1. Press Transducer principle (Transducer) points
Mainly moving coil (Dynamic) and electrostatic (Electrostatic) headphones into two categories, although in addition to these two categories there are a few other than magnetic, etc., but either have been eliminated or for professional use very little market share in this not discussed.
Dynamic headphones principle: the vast majority (more than about 99%) fall into this category ear headphones, the principle is similar to ordinary speakers, in a permanent magnetic field of the coil and the diaphragm connected to a coil driven diaphragm audible signal current driven
Electrostatic headphones: changes in the electric field diaphragm, diaphragm thin, accurate to a few microns (STAX current generation of electrostatic headphones diaphragm is accurate to 1.35 microns), the coil driven diaphragm sound driven by the electric force.
2, according to the degree of openness points
Mainly in open, semi-open, closed (closed).
(1) Open: general sense of hearing is a natural, comfortable to wear, common in home appreciation HIFI headphones, the sound can leak, and vice versa is also possible to hear outside sounds, oppression smaller ear headphones.
(2) semi-open: no strict rules, the sound can also be not only into out without, according to need and make the appropriate adjustments.
(3) Closed: earmuffs ear to prevent sound out of oppression large, clear sound correct positioning, professional *** fields such common, but these headphones have a serious drawback is that the bass sound pollution, W100 is a obvious examples.
3, according to zoning
Mainly home (Home), portable (Portable), *** (Monitor), Mix (Mix), head record (Binaural Recording)
Second, the headphone-related parameters
Impedance (Impedance)
Note the difference between the meaning of resistance in current (DC) in the world, the objects on the current role of obstruction is called resistance, but in the field of alternating current (AC) in addition to resistance will impede the current outside, capacitance and inductance will impede current flow, this effect is called reactance, and our daily said impedance is the resistance and reactance on vectors and.
Sensitivity (Sensitivity)
SPL pointing headphone input power of 1 milliwatt headset can be issued (decibels of sound pressure, the greater the volume the greater the sound pressure), so generally the higher the sensitivity, the smaller the impedance, the more likely headphones loud, more easy to drive.
Frequency Response (Frequency Response)
Frequency corresponding to the sensitivity of the frequency response is, the image is drawn into the frequency response curve of the human auditory sense can be achieved in the range of about 20Hz-20000Hz, the current technology have reached mature headphone this requirement.
Third, the quality evaluation terminology
Range: instrument or vocal range that can be achieved between the highest sound and the bass
Voices: also known as one of the basic properties of timbre, sounds, such as the erhu, pipa is a different tone
Bass: Music natural neutral antithesis, that sounds infected with some programs do not have their own characteristics, such as the kind of sound to get in front of a jar speech is typical coloration. Coloration indicates a reproduction signal more out (or reduce) some of the ingredients, it is clearly a distortion.
Distortion: output devices can not fully reproduce its input, resulting in a decrease distortion or signal component waveform. Dynamic: Allows maximum information with minimum ratio recorded information
Transient Response: Equipment for the music to follow the burst capacity. Good transient response equipment should be a signal to immediately respond to a signal a stop to a halt, never sloppy. (Typical musical instruments: piano)
SNR: also known as the signal to noise ratio, the strength of contrast useful signal components and noise, often expressed in decibels. The higher the SNR of the device, the less noise it generates.
Air flu: used to represent the open treble, or the sound field in the space between the instrument acoustic terms intervals. In this case, high-frequency response extends to 15kHz-20kHz. Antonym of "gray (dull)" and "thick (thick)".
Bass extension: refers to the lowest frequency audio equipment that can be reproduced. Department used to determine when the bass reproduction speaker sound system or to what extent can dive scale. For example, the low-frequency extension of small subwoofer can go to 40Hz, while the large subwoofer then dive to 16Hz.
Bright: refers to highlight 4kHz-8kHz high frequency band, this time relatively stronger than the fundamental harmonic. Bright itself is not a problem, live music concerts Jie bright sound, the problem is too bright and have a good sense of proportion, too bright (even howling) then annoying.
Fourth, on the amplifier aspects of knowledge
1, generally can be divided into transistor amplifier (stone) and the tube (tube amp) amplifier categories
2, the amplifier: preamplifier and power amplifier collectively.
(1) Power Amplifier: referred amplifier, used to enhance the signal power to drive the speakers sound of an electronic device. PA without source selection, volume control and other ancillary functions called after the class.
(2) Preamplifier: pre-amplification and power amplifier control section before, used to enhance the voltage amplitude of the signal, providing an input signal selection, tone adjustment and volume control functions. Preamplifier is also called before the class.
3, the CPI amplification (class-A): also known as Class A amplification. As a working state amplifier. At this point the transistor or tube amplifiers will be for the entire audio signal amplification.
B amplification (class-B): also known as Class B amplification. As a working state amplifier. At this point all the way to the transistor or tube amplifier will magnify the positive half of the audio signal, and the other way transistor or tube amplifier is amplified negative half of the signal.
Class AB amplification (class AB): also known as class AB amplification. A working state amplifier. At this point in the output stage of the amplifier output power will be amplified by the CPI state low, and high when the output power is then converted to B amplification.
4, on the headphone wire: Most headphone lines with copper as raw material, the average purity (generally with a few N represents, such as 4N, 6N ......) the higher the conductivity, the better, the smaller the signal distortion, common are:
TPC (copper): purity of 99.5%
OFC (oxygen-free copper): purity of 99.995%
LC-OFC (oxygen-free copper or crystalline linear crystallization oxygen-free copper): purity of 99.995%
OCC (single-crystal OFC): the highest purity, more than 99.996%, is divided into PC-OCC and UP-OCC
5, on the front-end equipment: Many HIFI enthusiast habits will be separated into two parts phonograph turntable and *** is to get better sound quality music.
Front: Multi-audio system refers to the signal source, such as a slow turn LP compact player or CD player, sometimes referred to as a tuner (tuner) processing signals received from the radio to the front stage.
CD turntable: the mechanical transmission part of the CD player out of the machine independent.
D / A Converter: digital audio products (such as CD, DVD) in the digital audio signal into an analog audio signal means. D / A converter can be made independent of the machine to match the CD turntable, in which case often referred to as *** device (DAC).
