pressure=p(x,t)=BkAsin(kx-ωt) http://www.physics.unomaha.edu/Sowell/phys2120/Lectures/Sound/Sound.pdf Surely, when loudness-intensity-pressure increases, so does the maximum displacement A of the speaker. Wrong thread title. My question is: Why increasing the maximum molecule displacement A increases sound pressure. They also say that the A of the speaker is equal to the maximum displacement "A" of the molecule. Why that?