Thread: Sound deadening
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      02-26-2016, 07:46 AM   #84
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Quote:
Originally Posted by nikotine30 View Post
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!

Please - your science is mucking up a great argument! If you could please stick to vague unprovable assertions and some overblown hyperbole, it would make this go much more smoothly.
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