Twice the sound level is +6dBA right?

[chico1st]

I have seen some conflicting info and I would just like to confirm that +6dBA is twice the sound level (noise). It makes sense to me because Sound level is the square of the sound amplitude but I have seen many a place saying that this thought is wrong.

thanks

[multisync]

if the voltage goes up by 2x that's +6db
if the voltage goes down by 1/2 that's -6db
if the power goes up by 2x that's +3db
if the power goes down by 1/2 that's -3db

your ears are logarithmic you need 10x (10db power) to hear 2x as loud volume (depends on frequency) see fletcher/munsen curves wiki

you need 1/10 th power to get to 1/2 as loud

[DF96]

You maybe confusing ratio with level. +6dB is a ratio, which is four times the power; other things being equal this also means twice the voltage or twice the sound pressure. +6dbA is a sound level, which is 6dB above the reference level (often 0.02mPa pressure?) and measured using an 'A weighting filter'. A bare dB figure is always expressing a ratio between two numbers. In some cases there may be a standard reference level but this should normally be indicated with a suffix e.g. dBm means dB with respect to 1mW. Unfortunately, sound people often say 6dB when they mean 6dBA.

As multisync says, 6dBA won't sound twice as loud as 0dBA.

[simon7000]

No 3 db is twice the sound pressure level. It is measured in power. Voltage times current is power so if you have a fixed resistance and double either voltage or current you also automatically double the other so you get four times the power or 6 db more.

The rule of thumb (which is inaccurate) is that 3 db is just a perceptible change and a 10 db increase sounds twice as loud.

[DF96]

According to the Australians sound pressure works like voltage, not power. 6dB is twice the sound pressure.

[simon7000]

Originally Posted by DF96

According to the Australians sound pressure works like voltage, not power. 6dB is twice the sound pressure.

That's nice. Why don't you take a sound level meter and measure any source. Then go to twice the measurement distance and take another reading. Let me know how much the level decreases as you double distance.

[sreten]

Hi,

+6dBA is 4 times the power according to A weighting. 1B or 10dB is x10.

SPL, like voltage levels in equipment, is rated according to the power.

So +3dB in real voltage level (2x) is actually +6dB(4x) in signal level.
+10dB in real voltage level (10x) is actually +20dB(100x) in signal level.
Same goes for SPL, up pressure by x1.4 and SPL doubles i.e. +3dB.

+3dBA is twice the power A weighted.

dB: What is a decibel? : Australians

Its not wrong, that what is says, if you can read.

+6dB SPL is twice the pressure, but not twice the SPL, its 4 times the SPL.

rgds, sreten.

[Pano]

But is it twice as loud?

[sreten]

Originally Posted by Pano

But is it twice as loud?

Hi, Of course not, that is accepted as ~ 10dB or 1 Bel, rgds, sreten.

[Pano]

Right. Thus the confusion. 3dB, 6dB, 10dB. Which is "twice as much"?