Yeah, dB is a measure of difference, not an absolute value. Every increase of 10dB represents twice as much volume, but that means 0dB is essentially just a reference point. Going from 0 to 10dB means you have doubled the volume. 20 is twice of 10, 30 is twice of 20, etc… But what is twice of 0? If 0 were an absolute value, the entire scale would break down because 0x2 is still 0.
People have a really hard time wrapping their minds around the logarithmic growth of the dB scale… For reference, a rock concert can easily hit 120dB, but the loudest sound that earth’s atmosphere can support is ~194dB. Because sound is a pressure wave with a compression and expansion. After 194dB, the atmospheric pressure isn’t enough to fully expand into the void after the compression. Once you get above that ~194dB threshold, it stops being a sound wave with a distinct push-pull, and becomes a solid shockwave that is all push. Above 194dB, it’s essentially an explosive wave.
And to briefly touch on what you mentioned about perception, there’s also the fact that different frequencies require different amounts of power to produce the same volume. Lower bass frequencies require more power to produce the same volume, because the bass waves are physically larger and require more motion from the speakers to produce. If you want a demonstration, go look up the difference between white noise and pink noise.
White noise has the same amount of power throughout the entire audio spectrum, but it tends to sound relatively high pitched and tinny. This is because those lower frequencies are quieter. In comparison, pink noise has a curved power distribution, mapped to how much power it takes to produce the same volume. This means it sounds much more “full”, as the low end is actually balanced with the highs. But listening to pink noise will be wildly different on a phone speaker vs a car stereo, because the phone speaker physically isn’t large enough to truly produce those low notes.
Yeah, dB is a measure of difference, not an absolute value. Every increase of 10dB represents twice as much volume, but that means 0dB is essentially just a reference point. Going from 0 to 10dB means you have doubled the volume. 20 is twice of 10, 30 is twice of 20, etc… But what is twice of 0? If 0 were an absolute value, the entire scale would break down because 0x2 is still 0.
People have a really hard time wrapping their minds around the logarithmic growth of the dB scale… For reference, a rock concert can easily hit 120dB, but the loudest sound that earth’s atmosphere can support is ~194dB. Because sound is a pressure wave with a compression and expansion. After 194dB, the atmospheric pressure isn’t enough to fully expand into the void after the compression. Once you get above that ~194dB threshold, it stops being a sound wave with a distinct push-pull, and becomes a solid shockwave that is all push. Above 194dB, it’s essentially an explosive wave.
And to briefly touch on what you mentioned about perception, there’s also the fact that different frequencies require different amounts of power to produce the same volume. Lower bass frequencies require more power to produce the same volume, because the bass waves are physically larger and require more motion from the speakers to produce. If you want a demonstration, go look up the difference between white noise and pink noise.
White noise has the same amount of power throughout the entire audio spectrum, but it tends to sound relatively high pitched and tinny. This is because those lower frequencies are quieter. In comparison, pink noise has a curved power distribution, mapped to how much power it takes to produce the same volume. This means it sounds much more “full”, as the low end is actually balanced with the highs. But listening to pink noise will be wildly different on a phone speaker vs a car stereo, because the phone speaker physically isn’t large enough to truly produce those low notes.