Quote:
Originally Posted by Adem1534
No, no, no. Let me clear this up. The decibal scale is logmarthmic, not linear.
72 decibals is approximately 58% louder than 70 decibals.
That's a lot!!!
|
Adem1534, thanks for your comments. The decibel scale is indeed measured on a logarithmic scale, and you are correct that a 2 db gain requires 58% more "energy".
What does "energy" mean? Suppose we are talking about sound reproduction. Suppose that you have a 100W amplifier that you turn up to the max, and you measure your speakers producing 90 db, which is quite loud. If you were a headbanger heavy metal type and wanted to play it even louder, you could think about upgrading to a more powerful amplifier. How much more powerful? Well, it turns out that you really need a MUCH more powerful amplifier to produce a significant increase in loudness.
This is a phenomenon well known in the audio world. You need increasingly more powerful and heavy amplifiers to produce only very modest gains in music loudness.
Compared to a 100W amplifier:
- A 200W amplifier will play only 3 db louder, which is "barely perceptibly louder"
- A 400W amplifier will play only 6 db louder, which is "clearly noticeably louder"
Now coming back to the car world (and to your example), while it's true that 72 db has more 58% more "energy" than 70 db, our ears simply don't perceive it that way. A 3 db increase is
barely perceptible to the human ear. As Kantalis said, it takes a 10 db increase for our ears to perceive double the loudness.
For reference, see the chart below: 3 db is only about 23% louder to our ears, and 2 db would be maybe somewhere around 15%.
We can conclude that a BMW M2 (72 db) is only about 15% louder than a BMW 340i (70 db) at a constant 70 MPH, which is really not a lot louder!