Explanation of speaker power parameters for the mo

Knowledge supplement explanation of speaker power parameters

speaking of speaker parameters, power is the most mentioned by us. We can even easily see that two speakers with the same power have different performances at medium or high volume, and sound distortion occurs from time to time. Is this group of data related to power output a "digital game"

the main function of the power amplifier is to amplify the signal and provide sufficient power for the load (speaker). The influence of power amplifier on sound quality mainly depends on whether the input signal can be amplified and transmitted without distortion, so as to give enough power to the load. The signal amplified and transmitted by power amplifier is different from simple harmonic signal, which is a complex signal with instantaneous changes

if we look at this signal from the waveform, this original signal has many spikes. Their energy is not large, but the peaks are very sharp and high. These spikes contribute little to loudness, but have a great impact on sound quality. If clipping occurs, the amplified sound sounds dry and hard. This has something to do with the details of what we usually call subjective listening. If we only pay attention to the transmission of energy (the corresponding amount is loudness) and do not pay attention to the change of waveform in the transmission process (causing distortion), then we may hear a loud sound, but it is not good

for the active speaker, the power amplifier is built inside the speaker, and its work is also to drive the speaker and bring enough output power to the speaker. The nominal writing of speaker power we see is not very standard. Generally, the power of "speaker" marked by speaker manufacturers refers to the "output power (RMS)" of power amplifier (power amplification circuit part of active speaker), and RMS (rootmeansquare) refers to root mean square. At present, in the marking of multimedia speakers, most of it is root mean square power

root mean square power is different from average power and rated power. The specific algorithm is to take the mean value of the square of the power value at each point of the sample and then develop the square. We won't go into the calculation of the specific root mean square for the time being. What we need to discuss next is the relationship between the "root mean square" power and the rated power, speaker power

as mentioned earlier, the signal amplified by the power amplifier is a complex signal. According to the investigation results of various musical instruments and program signals of different operas in acoustic engineering, the ratio of the maximum root mean square power (i.e. the peak peak power of the program signal on the load) to the average root mean square power (i.e. the average power of the program signal on the load) of most program signals is 3 ~ 10, up to 12.7

if the rated power of the power amplifier corresponds to the average root mean square power of the program signal, the maximum output power of the power amplifier should be 3 ~ 10 times to ensure that the output signal does not appear clipping. This is why the power of power amplifier we choose is much larger than the average root mean square power of amplified program signal, which is also what we usually call power reserve

from the current low-end products, the maximum output power of the power amplifier should not be 10 times the power reserve of the signal root mean square power, and the power reserve must be different when we design. This is one of the reasons why we will encounter distortion problems at different or higher volumes during normal testing. On the other hand, when marking the power of multimedia speakers, it is rarely explained that the integrated interactive power in this area is the rated power, maximum output power, output RMS power and even speaker power, which is a very confusing parameter index

in addition, if we pay attention to the nameplate on some speakers, there is also a power related value on it. What is the relationship between this value and the output of the power amplifier? In the design documents, we can see the following statements: "in order to ensure the safety of the loudspeaker system connected to the power amplifier, the rated output power of the power amplifier is required to be equivalent to the nominal power of the loudspeaker system connected", "in order to ensure sufficient power reserve, a power amplifier of 1.2 ~ 2 times the loudspeaker power is usually selected", etc. This formulation is actually incorrect. The power of power amplifier is not the same as that of loudspeaker

the output power of power amplifier generally refers to the sinusoidal output power under certain distortion restrictions. We usually see that manufacturers mark the specified total harmonic distortion of 0.1% after the bunched cable combustion experimental machine with power safety must comply with gb/t18380.31 (2) 008 and iec60332 (3) (1) 0/2009 standards. When the output signal of the power amplifier on the rated load reaches this distortion, the output voltage is called the maximum output voltage. Using this voltage to calculate the output power of the power amplifier is the nominal output power of the power amplifier, This can also be understood as the maximum output power of the power amplifier

as for the nominal power of the loudspeaker, the manufacturer often provides powder noise power, which refers to the power that feeds the specified analog program signal within the rated frequency range of the loudspeaker and works continuously for 100 hours without thermal and mechanical damage. Obviously, these two powers are stipulated and tested from completely different angles, and they are not comparable. If the manufacturer can provide the sinusoidal power of the loudspeaker (referring to the power fed when the sinusoidal signal is used as the test signal in close cooperation with the designer of self 4. User's performance failure in normal use and double clutch transmission), the two are comparable

however, manufacturers generally do not provide this data. So, for speakers, is there a certain corresponding relationship between the powder noise power and sinusoidal power of speakers? The answer is - no! The powder noise power and sinusoidal power of loudspeakers are completely different for loudspeakers with different structures, materials and specifications, and the latter is also related to frequency. Therefore, it is not advisable to compare the power of power amplifier with the nominal power of loudspeaker to characterize its power reserve in the design of speaker and power amplifier

obviously, it is meaningless to compare the speaker power with the power of the power amplifier. As you can see from the above, the topic of whether we are talking about sufficient power and sufficient power reserve at present can only be based on the subjective feeling of listening. It is meaningless to look at the annotation on the speaker, because everyone's annotation methods are not standardized, and there is naturally no comparability due to different standards