Frequency Characteristics Of Loudspeakers
Sound is caused by vibration, when it comes to audible objects, we all think of speakers, which is the trumpet we often say.
The loudspeaker mainly consists of permanent magnet (horseshoe type), armature (tongue spring), coil, paper basin and basin frame. The tongue spring coil generally uses 0. The enameled wire around the 08mm is made of 4000~5000 turn, so its DC resistance is much higher than the loudspeaker we see now, reaching $number ohm. Speaker Its characteristics are: high sensitivity, simple structure and low cost.
The main parameters of loudspeaker are rated impedance, power, frequency characteristic, resonant frequency, sensitivity, distortion, equivalent mass, equivalent smoothness, elasticity coefficient, Speaker equivalent volume of total quality factor, equivalent vibration radius, magnetic induction, magnetic flux, linear range, directivity, etc.
1. Rated Impedance: Speaker rated impedance is also known as nominal impedance value, that is, the minimum impedance of the loudspeaker after the resonant peak, there are several 4ω, 6ω, 8ω, 16ω and 32ω.
The rated impedance is usually about 1.1 times times the DC resistance of the loudspeaker sound coil.
2. Power: The power of the loudspeaker is divided into the rated power, the minimum power, the maximum power and the instantaneous power, and the units are W.
Rated power, also known as nominal power, Speaker refers to the speaker for a long period of normal continuous work without significant distortion of the input average power.
The minimum power, also known as the starting power, refers to the reference power value of the loudspeaker that can be driven by the work.
Maximum power, also known as the largest load power, is the maximum input power that a loudspeaker can withstand for a long period of continuous work.
Instantaneous power, also known as transient power, refers to the loudspeaker in a short time (10ms) can withstand the maximum power, generally the rated power of 8~30 times.
3. Frequency characteristic: Loudspeaker frequency characteristic refers to when the input loudspeaker's signal voltage is invariable, the loudspeaker has the output sound pressure on the reference axis changes with the input signal frequency change the law. It is a frequency response (short frequency) curve with varying frequency, which reflects the radiation ability of loudspeakers to different frequencies of sound.
The frequency response curve of the loudspeaker is an irregular continuous curve with many peaks and valleys, and the resonant frequency of the loudspeaker is used as the low-frequency frequency, and the intersection of the high-frequency end of the frequency response curve is used as the high-frequency upper frequency. Speaker The frequency range between the low-frequency lower bound and the high-frequency upper limit. Known as the effective frequency range of speakers.
The more flat the frequency-response curve of the loudspeaker indicates, the smaller the frequency distortion, the wider the effective frequency range.
The frequency range of the general bass loudspeaker is between 20hz~3khz, the frequency range of the alto loudspeaker is between 500hz~5khz, and the frequency range of the treble loudspeaker is between 2~20khz.
4. Resonant frequency: The resonant frequency is the lowest frequency that the loudspeaker can replay, Speaker which is related to the size of the speaker aperture.
The resonant frequency value of the bass loudspeaker is generally decreased with the increase of its aperture, the resonant frequency of 6in (in=0.0254m) Bass Loudspeaker is about 50HZ, 8in (in=0.0254m) Bass speaker resonant frequency is around 40HZ, The resonant frequency of the 10in bass speaker is about 30HZ, and the resonant frequency of the 12in subwoofer is about 20HZ.
Resonant frequency is an important parameter that determines the low-frequency characteristic of loudspeaker, the lower the value, Speaker the better the texture and intensity of the loudspeaker replay bass.
5. Sensitivity: The sensitivity is also called the output sound pressure level, mainly used to reflect the speaker's electro-acoustic conversion efficiency. With a high sensitivity speaker, Speaker it can be propelled with a smaller electric power.
The sensitivity of loudspeaker is characterized by the sensitivity level and the average characteristic sensitivity, the former is the most commonly used and the error is small.
6. Distortion: The distortion of the loudspeaker mainly shows that there is a difference between the replay sound and the original sound. It is also divided into harmonic distortion, transient distortion, intermodulation distortion and phase distortion.
7. Equivalent mass: the equivalent mass of the loudspeaker is also called the vibration quality, which is the sum of the static mass of the loudspeaker vibration system (the quality of the vibrating film and the sound coil itself) and the same vibration mass (the quality of the part of the air layer that vibrates along both sides of the vibrating film).
The equivalent mass is proportional to the aperture of the loudspeaker, Speaker and the resonant frequency of the loudspeaker is inversely related.
8. Equivalent bedding: The equivalent CIS is also known as Force smoothing or sound-smoothing, indicating the tightness of the loudspeaker mounting system (the softness of the folded and locating pieces) or the compliance of the displacement after force.
9. Elasticity coefficient: The elastic coefficient of the loudspeaker is also called the equivalent force stiffness of the vibrating system, which is the parameter that indicates the cone ring and the rigidity of the locating support piece, which is proportional to the resonant frequency of the loudspeaker, and inversely to the equivalent mass of the vibrating system.
$number． Total Quality factor: The total quality factor of the loudspeaker is also called the QTS value, which is used to reflect the slow energy consumption of the vibrating system, that is, Speaker the size of the vibration system loss.
$number． Equivalent Volume: Speaker equivalent volume refers to the equivalent air volume of the loudspeaker vibration system. The larger the aperture of the loudspeaker, Speaker the greater the equivalent volume.
$number． Equivalent vibration radius: the equivalent vibration radius of the loudspeaker is also known as the effective area of the vibrating film, which indicates the area which helps the sound radiation, generally refers to the length from the center of the diaphragm to the middle of the folding ring.
$number． Magnetic induction and magnetic flux: Electromagnetic intensity is also called the gap strength, used to indicate the quality of the magnetic field strength in the speaker air gap.