In article ,
Robert Bonomi wrote:
In article .com,
Never Enough Money wrote:
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!

"yeah, *BUT*" applies.

first, "spelling counts" it is 'decibels', not decibles. regular
metric units -- a deci-bel == 1/10 of a 'bel' (which is a log10 scale)

3 decibels -- or "0.3 bel" roughly corresponds (actually 0.3020+ bel) to

argh! typo; make that .3010+ (.301029995663981+ for the finicky

a doubling of the actual power in the acoustic signal.

So, yes, the _energy_, or "power" in the noise from the shop vac is 256 times
higher than the Fein.

HOWEVER, the sensitivity of the human ear is _also_ more-or-less logarithmic,
with regard to the power of the audio signal it receives.

Thus the Shop Vac will "apparently sound" only about 8-10 times louder than
the Fein.