Piezo buzzer VS Magnetic buzzer

There are two types of buzzers, piezo and magnetic type.
A piezo buzzer generates sound because of the piezoelectric effect from the piezoelectric ceramic which drives the metallic diaphragm to vibrate. A magnetic buzzer is based on the electromagnetic principle, the metal diaphragm is pulled when input the power, and spring back without power.
The piezo buzzer is driven by square waves, and the magnetic buzzer needs 1/2 square waves to drive.
We suggest inputting higher voltage for a piezo buzzer, normally over 9V to have enough SPL. On the other hand, a magnetic buzzer can be driven to generate 85 dB by only 1.5V, but the consumption of the current will be much higher than Piezo one.
To compare the two types of buzzers, the magnetic type can have lower frequency response with the same dimension.
Though being limited by the dimension, the SPL of a magnetic buzzer can only reach to 90 dB. The piezo buzzer can achieve the SPL of 120 dB in some spec., some larger size can also easily reach to 100 dB.
蜂鳴器分為壓電式及電磁式的二大類,
壓電式蜂鳴器是以壓電陶瓷的壓電效應,來帶動金屬片的振動而發聲,
電磁式的蜂鳴器,則是用電磁的原理,通電時將金屬振動膜吸下,不通電時依振動膜的彈力彈回,
故壓電式蜂鳴器是以方波來驅動,電磁式是1/2方波驅動,
壓電式蜂鳴器需要比較高的電壓才能有足夠的音壓,一般建議為9V以上,
電磁式蜂鳴器,用1.5V就可以發出85dB以上的音壓了,唯消耗電流會大大的高於壓電式蜂鳴器,
而在相同的尺寸時,電磁式的蜂鳴器,響應頻率可以做的比較低.
電磁式蜂鳴器的音壓一般最多到90dB, 壓電的有些規格,可以達到120dB以上,較大尺寸的也很容易達到100dB.