DB=1 watt sound pressure level+10xlog power
　　Csp58 speaker 1 watt sound pressure level=102.5dB,full power 300 watt sound pressure level calculation:
　　300 watt sound pressure level dB=102.5+10xlog300=102.5+10x2.4772=127.5dB
　　Csp58 speaker 1 watt sound pressure level=102.5dB,maximum power 600 watt sound pressure level calculation:
　　600 watt sound pressure level dB=102.5+10xlog600=102.5+10x2.7781=130.3dB,or sensitivity increased by 3dB by doubling the power.The sound pressure level at 600 watt power is 127.5+3=130.5dB
　　Some manufacturers also learn from others to label"maximum output sound pressure level",but they don't know where to copy it-we don't label this parameter-what's the point of copying data?They even steal the trademark.I heard it's still an engineer,and the mistake is too outrageous.We hope someone notifies them and makes the necessary changes!We don't want too many amateurs.It makes sense for Peyer to sell over 100000 speakers,at least they understand dB.
　　It's not over yet.Sound propagation is related to distance.If distance wasn't mentioned earlier,I didn't want to scare you away.I've learned this already,so let's learn more(which is more difficult than before).
　　Sound propagates in the air,centered around a point and spreading outward in a spherical shape(regardless of whether the type of sound propagation is longitudinal waves).Assuming the radius of the ball is 1 meter,the surface area of the ball is 4x3.14x12=12.56M2.If the radius is doubled to 2 meters,the surface area of the ball is 4x3.14x22=50.24M2;50.24/12.56=4,indicating a doubling of distance(radius)and a 4-fold increase in surface area.If the power remains unchanged and the area increases by 4 times,the power per unit area will only be 1/4 of the original(the original power was 1 watt,and this 1 watt power was distributed over the area of 1M2;now the power is still 1 watt,but the area has increased to 4M2,so the power per 1M2 on this 4M2 is 1/4.The most important thing here is how to understand how increasing the area by 4 times leads to a decrease in power to 1/4,and let your imagination know.After thinking it through,the following is not difficult).
　　For every doubling of power,the sound pressure level increases by 3dB;On the contrary,for every doubling of power,the sound pressure level gradually decreases by 3dB,with 1 doubling=1/2,1/2 doubling=1/4,and 3dB+3dB=6dB.As it is a decrease,a"negative"sign is added before it.Calculate using the previous program:
　　Double the distance,sound pressure level=10log(1/4)=-10x0.6021=-6dB1q!O4pK
　　Our experience is that for every doubling of distance,the sound pressure level decreases by 6dB.
　　The standard formula for calculating distance and sound pressure level:
　　DB=1 meter sound pressure level-20xlog distance
　　(Negative sign indicates reduction,20xlog distance=2x10xlog distance≥10xlog power 2)
　　Derivation of sound pressure level dB at 1 meter 1 watt and 2 meter 1 watt(multiplied by 10 to 20)1 watt∞1 watt 10 log4пR2∞10loп(2r)2
　　10log4пR2∞10log(4пr)2
　　10log4пR2∞2x10log4пR
　　10log4пR2∞20log4пR
　　For example,Csp58,sound pressure level at 1 meter=102.5dB,sound pressure level at 40 meters:
　　=102.5-20xlog40=102.5-20x1.6021=70.5dB
　　Csp58 full power 300 watts,sound pressure level calculation at 40 meters:
　　First,calculate the 1-meter full power sound pressure level(127.5dB),and then apply the"distance and sound pressure level"program=127.5-20xlog40=95.5dB
　　Summary:
　　Power doubled,sensitivity increased by 3dB
　　Double the distance and reduce sensitivity by 6dB