"Never Enough Money" wrote in message
oups.com...
Fein Turbo II is rated at 58 decibles. The Shop Vac "Quiet Deluxe 6.5
HP" is rated at 82 decibels.

The rule of thumb I know is that 3 decibles corresponds to a doubling.
Thus the Shop Vac Quiet Deluxe 6.5 HP is 24 decibels louder, or 3 db +
3 db + ... + 3 db (8 times), or 2x2x2x2x2x2x2x2 = 2 to the 8'th power =
256 times louder.

Is that correct? If so, holy moly!

Sort of. It is a logorithmic scale and you you would be correct to say that
the amplitue of the sound wave is about 256 (actually 240) times greater.
Does that mean that percieved loudness is that much greater?.... no probably
not as that's not really how human hearing (both the ear and brain) works.
It's king of hard to objectively quantify peception.

-Steve