Decibel and volume level
Decibel ("dB" for short) is a unit of counting about the ratio of two numbers. Well, I understand that many people are not very interested in this, so I will simplify things and try not to involve the problem of "mathematics". About logarithmic scale, we can't just understand it as usual-for example, doubling the number will increase, but it doesn't mean "doubling". For example, 100dB is twice as loud as 50dB, but it doesn't mean its loudness is twice as loud as 50dB. When it comes to "loudness", it involves the sound pressure level (also known as SPL), and the level increase of 10dB will "double" the loudness. In other words, if a speaker that can produce 90dB SPL is compared with a speaker that can produce 100dB, most listeners will think that the "loudness" of the second speaker is about twice that of the first speaker.
Wattage, power and SPL
So what wattage will double the loudness? Let's assume that there are two speakers, one is 10 watt, and the second is 20 watt. The wattage of a 20-watt speaker is twice that of another speaker, but after conversion, the wattage of twice will only increase by 3dB SPL. Remember, if you want to double the loudness of the speaker, you need to add 10dB to the speaker. A 20-watt speaker will double the wattage of a 10-watt speaker, but it will not produce twice the loudness. The same is true for high-power equipment. A100W speaker will not produce twice the loudness as a 50W speaker. Assuming the same speaker, it will only increase the loudness by 3dB. Although the change of volume will be very obvious, it will never double the loudness.
Speaker sensitivity level
The speakers in the sound box also have specifications in sensitivity and effect-they will convert the input electric energy into acoustic energy. Dynamic dynamic speakers (which you can find in most guitars and woofers) are very inefficient. They convert most of the input power into heat, not sound. Generally, the measurement of speaker sensitivity will be carried out in an anechoic room (a room without reflection and sound insulation) and described in the following units/formats:
90dB @ 1W/ 1m
The power of 90 decibels (SPL) and 1 watt produces a sound pressure level of 90 decibels at a distance of one meter from the speaker. An efficient speaker will have higher sensitivity, while an inefficient speaker will have lower sensitivity. An efficient speaker will make your speaker louder. (as shown in figure 1)
Figure 1: Although the power of these two speakers is similar (20 watts and 18 watts), the sound of the left speaker is louder because of the installation of an efficient speaker.
combine
So let's assume that there is a speaker with a sensitivity of 90dB @ 1W/ 1m and a power of 100W. If we adjust the power of the speaker to 1W, the distance at 1m will generate 90dB. If we adjust the power to 2 watts, the measured value of SPL will become 93dB. If we increase the power of the speaker to 10W, the measured value of SPL will increase to 100dB. At this time, the loudness will be doubled compared with the previous power of 1 watt. So in fact, they need more power than 10 to make us feel the loudness double. Since the maximum power of this speaker is100W, we can double the volume. Theoretically, power higher than100W will produce 1 10dB SPL. 1W =90dB。 100W or higher power = 1 10dB. This is a huge power increase, but you can only feel that the volume level has increased by four times.
As you can see, if you want to "double" the volume effect, you need to increase the power and the wattage of the speaker. Let's introduce the sensitivity/efficiency of the loudspeaker into this formula. If we replace the 90dB @ 1W/ 1m speaker with100dB @1w/1m, its digital change is very obvious. We know that the input power of 1 watt will provide us with 100dB SPL. Remember, the first speaker needs 10 watt to achieve the same volume! Therefore, installing efficient speakers will bring us more volume. Similarly, it also applies to the maximum power handling capacity of all speakers. Assuming that the speaker of100db @1w/1m can handle100w at the highest, it can provide120dbspl at the highest; ; However, the highest level of 90dB @1w/1m100w speaker is only 1 10dB SPL.
Speaker power+speaker efficiency and power handling capacity = maximum volume.
So please remember that increasing the power of the speaker will make the sound louder, and improving the sensitivity of the speaker will make the speaker have higher power within the available power range. Therefore, this also means that the "loudness" of any speaker cannot be judged by wattage alone. You must know the power handling ability and sensitivity of the speaker, which is an important factor to enhance the loudness of the speaker. If your 15W speaker is equipped with a relatively inefficient speaker, but its loudness is enough to meet your requirements, then you don't need to buy a high-wattage speaker-you just need to replace an efficient speaker, such as the electronic sound EVM 12L (Figure 2), which can not only meet your demand for volume, but also do not need to replace the whole speaker. Similarly, you may not need a 100 watt speaker; If the 95dB @ 1W/ 1m speaker in the 50W speaker is replaced by1kloc-0/db @1w/1m speaker, the volume level will change obviously, so you need to accept that .. in fact, you use inefficient speakers.
Figure 2: Replacing inefficient speakers with efficient speakers, such as this E/V EVM 12L, will make the speakers louder.
Of course, if you really want to make the speaker loud, then you need a speaker with high power, high efficiency and strong power handling ability.
Source: Harmony Center
Compile: Vader