[Shuruga2]

i've been looking around at some sites for case fans and i'm unsure what to get.
part of my problem is dBA:cfm. whats good and what isnt?

some numbers: (all from the 2cooltek web site)
vantec stealth 92mm at 20dBA : 28cfm ($11.00)
80mm at 21dBA : 27cfm ($11.00)
vantec tornado 92mm at 56.4dBA : 119cfm ($18.00)
80mm at 55.2dBA : 84.1cfm ($18.00)

from the numbers i can see that the tornado is almost 3 times louder, but how loud exactly is 56dBA? (deltas are always called 'screamers' and they are only 48.5 dBA)
28cfm seems really small in comparison to 119...

cooling as of right now (mid sized tower):
bottom front 80mm intake, or maybe its a 92.
80mm exhaust in the back ducted to the coolermaster that came with my 1.4 t-bird
hard drive cooler in the front with the fans turned around to exhaust (my hard drive is actually mounted in the lower rack)
the side of the case is off


what i'm thinking of:
+ 2 80mm fans on the side of the case, intake. one over the cards and the other over a thermalright ax-7
+ a 92mm fan to exhaust on the top of the case
maybe getting rid of the hard drive cooler. if i keep it i will be mounting a hd behind it and turning the fans around


q's:
those fans are just examples, does another company make some with a good compromise between dBA:cfm?
instead of the 80 over the cpu would a duct to a hole in the same place work almost as well?
what about high cfm 80mm fans over the cards, on the heatsink and a 92 exhausting out the top with a low cfm over the cpu?
how hard would it be to install a (rheobus/rheostat.. whats the diff?) on each of the 3 new fans?
with 3 80s blowing in do i really need a fan on the top to exhaust?
a good place to order some of this stuff (fans, grilles, heatsink) from? pref. in canada.

thanks for your time.

[Carnil]

Originally posted by Shuruga2
from the numbers i can see that the tornado is almost 3 times louder, but how loud exactly is 56dBA? (deltas are always called 'screamers' and they are only 48.5 dBA)

Incorrect. If I'm remembering my dB -> loudness conversion correctly, a difference of 36 dB is about five thousand times louder. The 20 dB fan will be whisper-quiet, while the 56 dB fan will be quite loud. (See http://www.coolmath.com/decibels1.htm for examples of how loud different decibel levels are)

[Luie]

"Cool" site you got there!

[SkyHook]

I was a heavy equipment operator for nearly 20 years, I am used to working in a noisy enviroment. I recently got a Vantec Tornado the 80mm variety and it is a super fan, and inside of my case as a cpu cooler fan it is within my tolerance but then I tried using it for an intake fan at the front of my case and it was impossible for me to stand. A friend called on the phone while I had it mounted up front and told me to turn the TV down cause he couldn't hear me over the roar(high pitched roar).

Just my experience, I love them for cooler fans but not for intakes

SkyHook

[Overload]

DB or decibels is in a logarithmic scale. So each increment is ten times the previous. To convert to a normal linear amplitude measurement use this equation: dB = 20*log(A)
At least that’s how is done in audio. Here is a table that might be more useful.

Whisper 10 Barely Audible
Quiet Conversation 30 Faintly Heard
Average Office 50 Moderate Level
Summer Nocturnal Insects 60 Moderate Level
Noisy Office 70 Loud
Average Street Traffic 85 Very Loud
Jackhammer 100 Extremely Loud
Jet Aircraft Taking Off 120 Physical Pain

[Overload]

hmm... that table didn't turn out how i wanted. oh well. BTW i have a home theatre subwoofer capable of producing over 100dB

[SlackerTK421]

I have 2x 80mm Tornados for intake, they are noisy. I use a variable speed baybus to lower the noise while browsing the net. The performance is worth the noise though when you need it.

[Luie]

Around how many dB is your tornado when it is in its quietest working state?