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How to judge the actual power of the speaker

Views: 45     Author: Site Editor     Publish Time: 2021-07-02      Origin: Site

  Recently, I have always encountered the problem of exaggerated speaker power in customer enquiries. For example, a 4-inch speaker customer told me that the power is 50W or more. This is completely nonsense. I want to say that the manufacturer with such a label is fooling someone. Not every customer is professional, but every supplier should be professional. Let me try to teach the unprofessional customers how to find suitable speakers.

   I first attach a parameter table of our company’s loudspeaker, and then we will explain it according to this parameter chart.



1额定功率Rate Power


2最大功率Max Power


3灵敏度 S.P.L

91±3dB    (AT 1M/1W,

Average of  0.6,0.8,1.0,1.2KHZ)

4阻抗 Impedance



Frequency Range


6共振频率(F0)Resonance Frequency


7失真率 Distortion


8磁铁尺寸 Magnet Size

Φ32*18*6mm double magnet

9重量 Weight


10外径 Size


11音圈 Voice Coil

Φ13.28mm 胶管 KSV+Cu

12鼓纸 Cone


13额定电压 Rate Voltage


14温度 Temperature

Operating temperature:-30℃ to + 75℃

Storage temperature:-40℃ to +85℃

  We see that the first rated power is 5W, this power is the power that the real speaker can reach under normal working conditions, and the second maximum power is 6W, which can be reached under occasional overload working conditions. We all know that overloading will damage the machine, and the same will reduce the service life of the loudspeaker for a long time.

  Let's look at the thirteenth rated voltage, this one is very interesting. Do you rarely see this parameter in the supplier's specifications? This value can be calculated completely, but for many non-professional personnel, it may be a little difficult for them to make a choice without guidance items in the specification.

1. What is the rated voltage?

The rated voltage is the voltage used when driving the speaker, and maintains a stable output, that is, the voltage under the normal working state of the speaker.

2. How is the rated voltage obtained?

  We see that the rated voltage indicated in my parameter table is 4.47V, 4.47=√(5*4), 5 is the rated power, and 4 is the impedance of the speaker. As long as we know two values, we can use this formula to derive another value. With this rated voltage, we can test the actual power of the speakers we bought.

  Let's take the speaker parameters in the above figure as an example. If we drive the speaker under the premise that the rated voltage is 4.47V and the speaker impedance is 4 ohms, the sound of the speaker is very normal and there is no abnormal noise, then we can determine the speaker's rated power is at 5W. On the contrary, if there is abnormal noise or the sound of the speaker sounds uncomfortable, then the power of the speaker we tested is less than 5W. In this way, we can easily determine the actual power of the speakers we purchased, and no longer need to listen to the sales staff.

  We can also use this method to test the maximum power of the loudspeaker. We only need to increase the driving voltage a small amount until the abnormal noise occurs, and then use the above formula to calculate the approximate maximum power.

  Well, I will share some simple knowledge here, I hope it can help you.Follow me, Chinese speaker manufacturers, follow-up will continue to update more industry knowledge.

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