I was asked a question that threw me

[morbo!]

hiya`s
Today I was asked what a db was?

I suppose i read way too much
Becase i was talking to a relitivy smart person
It threw me for a second.
my reply was
It`s the linear measurment of the exponental event of sound

I dont know if that was the right answer

But i got a firm nod and a i understand

Kinda left me wondering if i really did?

how close was i guy`s?

[clmrt]

The decibel (dB) is a measure of the ratio between two quantities, and is used in a wide variety of measurements in acoustics, physics and electronics. While originally only used for power and intensity ratios, it has come to be used more generally in engineering. The decibel is widely used in measurements of the loudness of sound. It is a "dimensionless unit" like percent. Decibels are useful because they allow even very large or small ratios to be represented with a conveniently small number (similar to scientific notation). This is achieved by using a logarithm.

[edit] Relation to Loudspeakers

Speaker sensitivity is usually given in dBSPL @ 1 Watt @ 1 meter.
The equation for dBSPL is :.
This means that a doubling in sound pressure output from a speaker relates to a 6 dBSPL increase.

[edit] A practical example

A fictional 2 way speaker (A box with separate driver for high("Treble") and low("Bass") ) has the following specs:
High driver: 92 dBSPL @ 1W @ 1m. A Low driver: 86 dBSPL @ 1W @ 1m. B
Now if we want to match the output of the two speakers so the sound is "equally loud" we need to do the following:
Get the difference between the two by subtracting the sensitivity:
Difference in sensitivity = A-B
= 92 dBSPL - 86 dBSPL
= 6 dBSPL
As we concluded earlier this 6dB difference requires that we double the power delivered to the low driver. Since a doubling in [power] relates to 3 dB, we need to adjust the cross-over unit in this system so that the [gain] of the Low signal is 3dB more than the Highs. If there is no crossover you can always adjust the Amplifier's output to be 3dB more

******

dB(SPL)
dB(Sound Pressure Level) — relative to 20 micropascals (μPa) = 2×10−5 Pa, the quietest sound a human can hear.[1] This is roughly the sound of a mosquito flying 3 metres away. This is often abbreviated to just "dB", which gives some the erroneous notion that "dB" is an absolute unit by itself.

[morbo!]

Thanks
Thats gonna take awhile to sink in.
But it appears my answer was`t too bad in terms of referance.

Wonder how i pulled that out my ass.

Just not wanting too appear stupid?

I was no where near the net or i prolly woulda googled it.