[Home Theater Network HDAV.com.cn] Now the development of home theater audio is not good, and the speaker is the one that is closest to people's life. Choosing a good speaker can bring you beautiful enjoyment, if you are unfortunately choose bad. Speakers, that will add noise to your ears. So how do you tell the difference between home theater audio? Let's take a look! In the entire audio system (including computer multimedia speakers), the speaker is used as a replay tool for the home theater audio system. It is the simplest but the most complicated equipment. Because it is responsible for the electro-acoustic conversion equipment, the playback effect is directly related to the quality of the entire system, so whether the speaker selection is appropriate is an important factor in determining whether a sound system can be matched and formed successfully. To determine the pros and cons of a pair of speakers, usually from the technical indicators and people's subjective listening and evaluation of the two aspects, the author at the intermediate level of this brief introduction, for the majority of friends in the formation of their own sound system reference. The International Electrotechnical Commission (IEC) has set a minimum standard for household Hi-Fi speakers. The standard file is coded as IEC-581-7. We only need to look at the specifications of the speaker to see if its technical parameters reach this point. The minimum standard can be more objective to determine whether the speaker is qualified. Some minimum standards for IEC-581-7 for home Hi-Fi speakers are: (1) Frequency characteristics: the deviation is within +4~8dB at 50Hz-12500Hz; the deviation is ≤±4dB in the frequency band of 100Hz~8kHz (2) Pointing characteristics: horizontal plane ±30?o, vertical plane ±10?o, frequency response curve deviation from positive axis ≤±4dB (3) Inconsistency of left and right channel speakers: the difference between the average sound pressures in the range of 250 Hz to 1 kHz ≥ 2 dB (4) Total harmonic distortion: ≤ 2% at 250 Hz to 1 kHz, ≤ 1% - 2% at 1 Hz to 2 kHz, ≤ 1% at 2 kHz to 6.3 kHz (5) Impedance: in the range of 20 Hz to 20 kHz, ≥ 80% of the rated impedance (6) Allowable power: ≥10W From the above standards, it is not difficult to see that the technical requirements of IEC Hi-Fi (high-fidelity) speakers are not very high, and the speakers produced by regular manufacturers on the market can basically meet or exceed these standards. So in this many qualified products, how to determine whether a pair of speakers is excellent from the technical indicators? I think the speaker is excellent? I think the speaker is mainly looking at the frequency response range, pointing characteristics, sensitivity, withstand power and impedance. Several indicators. Also pay attention to the top 10 tips for choosing a speaker: First, the tone is naturally balanced Second, the sound characteristics Third, acoustic dyeing Fourth, the speaker's sound environment 5. Listen to familiar music. Six, pay attention to coordination and matching Seven, should be heavy and not heavy Eight, no hurry and would rather spend more time Nine, compare at the same volume Ten, only buy it when you are obsessed The frequency response range refers to the range in which the speaker can replay the sound frequency band, which is generally expressed in Hz to kHz. Since the limits of the human ear to frequency audibility are 20 Hz to 20 kHz, as the age increases, the hearing of the human ear will drop to about 25 Hz to 16 kHz. Therefore, as a pair of excellent speakers, the frequency response range must of course reach or exceed this range. The pointing characteristic indicates the change in the output sound pressure level when the speaker deviates from the frontal axis, which has a large influence on the sound field width and positioning. However, the directivity of the speaker (mainly the medium and high frequency unit) is not as wide as possible, and the professional products have certain requirements. The well-designed unit (mainly the horn type) can be controlled in the specified range, and the sound pressure level drops less than 6dB. The general dome and cone units do not, and their directivity gradually narrows as the frequency increases. To point to the characteristics meet the requirements, the requirements for the unit used are: if the distance is less than 4 dB in the direction of 30?o from the positive axis, the frequency difference f and the equivalent radius a of the cone must satisfy f≤ 140/a, such as a 200mm (8-inch) speaker, the crossover point must be below 1650. Of course, some well-designed speaker units can also set the crossover point higher than the theoretical value, but whether it is low, medium or high frequency speakers, the caliber, crossover point and power should be considered when selecting ( Two-way frequency is especially important. Many of the two-way speakers only take into account the power capacity of the tweeter when dividing the frequency, and the crossover point is very high, ignoring the directivity requirement. This system is often only in the front of the speaker. It has a good frequency response, and after deviating from the axis, the frequency response is worse, affecting the width and positioning of the sound field. Sensitivity refers to the efficiency of the speaker's electroacoustic conversion. It is usually expressed in terms of sound pressure dB/W/m or dB (decibel). The meaning of this indicator is to point to the speaker input 1 watt of power, on the positive axis 1 meter away from the speaker. The magnitude of the sound pressure obtained. Hi-Fi playback requires a maximum output impedance of 110dB, which requires the speaker to have higher sensitivity and a certain power margin, preferably greater than 88dB, so that there are at least two advantages, first: the amplifier And the power capacity requirements of the speaker are reduced, and the cost of both is reduced (the sensitivity is 88dB to reach the output 110dB sound pressure level, there must be 160W input power, and for every 3dB increase in sensitivity, the power required to reach 110dB sound pressure level will drop by one. Double); second: can reduce distortion. Low sensitivity is required to achieve the same sound pressure level as the high sensitivity output, requiring more power and amplitude, but this will increase the nonlinear distortion and reduce the life of the speaker. Relatively speaking, the better speaker sensitivity is above 86dB. At this time, they will not have any problem with the amplifier with rated output power of only 50W, but it is not that the speakers with low sensitivity are not good, like some classic Hi in foreign countries. -End speakers, such as the LS 3/5A and ATC SCM-20, are less than 85dB sensitive. Therefore, as far as this indicator is concerned, of course, the bigger the better. Because the speaker with high sensitivity inputs the same power, the sound pressure obtained will be larger than that of the speaker with lower sensitivity. Conversely, in the case of the same sound pressure, it requires less power than the speaker with lower sensitivity. small. Therefore, sensitivity is an important technical indicator for evaluating whether a pair of speakers is easy to push. Withstand power is the amount of power that the speaker can withstand without causing excessive distortion. If the input exceeds the rated power (RNS) continuously to the speaker, the speaker will not only be distorted, but also be burned. Therefore, the larger the indicator, the better, but in practical applications, the chance of burning the RMS to 100W speaker is equal to zero, because the human ear can't bear the sound pressure it brings before it reaches this indicator. In multi-way crossover speakers, the chances of being easily burned are greatly reduced. Therefore, in the purchase of home theater audio equipment, in addition to pay attention to the power of the speaker, but also pay attention to what kind of material and structure manufacturing of the tweeter. More fresh and fun home theater information, please pay attention to home theater network (WeChat: cnhifi) http://, the country's most influential home theater audio player interactive media website. Electric Spiral Stove,Cooking Plate Stove,Electric Cook Stove,Spiral Hot Plate Electric Stove Shaoxing Haoda Electrical Appliance Co.,Ltd , https://www.hotplates.nl
