Quote:
Originally Posted by
OwnedINC 
Doesn't that only apply as long as the sounds are close in power?
Well, when you double something, you take the
same number twice, no?
Or if you're talking about actual power as in Watts, then adding 6dB to SPL takes double the wattage to produce.
EDIT: In addition to this for the OP
Understanding how sound pressure level works (ie: doubling every 6dB) will help you read reviews and comparisons of different fans, but you shouldn't ever try mixing different values from different batches of measurement, like different manufacturers stating whatever SPL levels for their fans at whatever RPM, or different reviews to other reviews. They rarely specify how are they measured and in which conditions, so you can't really directly compare them. (This is also because of different ambient noise, different other possibly noisy PC components, and very likely way different ambient temperatures). You should rather look at one of those huge fan "round-ups" where they take many fans and measure them in similar conditions. There you will see a better picture of how fans perform against each other. Just throwing this out there in case it's not obvious in the first place.
Here's one 2012 fan round-up for you
Also, if you ever want to find out your real SPL the fans and components are churning out after you've built the computer, you should rather get a SPL meter than try calculating different components and their reported/reviewed sound pressure levels together, they are unlikely to match and things like resonance, case and it's dampening properties will all affect the output somehow.
Edited by seepra - 11/8/12 at 6:45pm
