fan noise

This is a discussion about fan noise in the Windows Hardware category; I'm building a new system soon and there's one question that's been bothering me. If I have a fan that's running at 40 dba and 2 that are running at 30 dba, does that mean I hear 100 dba of noise, or just 40? The #s are arbitrary, but basically do the volumes add up or does only the loudest one count?.

Windows Hardware 9627 This topic was started by , . Last reply by ,


data/avatar/default/avatar14.webp

21 Posts
Location -
Joined 2000-05-14
I'm building a new system soon and there's one question that's been bothering me. If I have a fan that's running at 40 dba and 2 that are running at 30 dba, does that mean I hear 100 dba of noise, or just 40? The #s are arbitrary, but basically do the volumes add up or does only the loudest one count?

Participate in our website and join the conversation

You already have an account on our website? To log in, use the link provided below.
Login
Create a new user account. Registration is free and takes only a few seconds.
Register
This subject has been archived. New comments and votes cannot be submitted.
Apr 2
Created
Apr 3
Last Response
0
Likes
3 minutes
Read Time
User User User User User User
Users

Responses to this topic


data/avatar/default/avatar16.webp

1615 Posts
Location -
Joined 2000-03-25
it probly adds to some extent but it certianly would not double the noise or anything like that

data/avatar/default/avatar40.webp

3087 Posts
Location -
Joined 2001-01-21
I have plenty of fans in my case, so my system sounds like a jet all the time. You'll get used to it...what are you saying, speak up, dammit!
It will be kinda loud, but it depends on how many youve got.

data/avatar/default/avatar17.webp

757 Posts
Location -
Joined 2000-10-14
The dba is a ratio
xdba = 10Log(Pout/atto watt)
to get the new db add the total power (just use some ohms law) then divide by an atto watt, log that, then multiply by 10.
So from what i calculated you should hear 40.79 dba.

data/avatar/default/avatar24.webp

97 Posts
Location -
Joined 2000-07-07
Decibels are log-based, which means that for every increase of 10 dB the loudness is multiplied by 10. The math behind this is nasty, but 40 dB + 30 dB + 30 dB = about 41 dB, which isn't much of a difference to the human ear above 40 dB.
 
If you're really concerned, PC Power & Cooling sells some really quiet fans. When they say they're silent, they mean it. I can't tell they're on unless I press my ear to the case.

data/avatar/default/avatar14.webp

21 Posts
Location -
Joined 2000-05-14
OP
Thank you all for the quick responses! I am now a much better informed shopper.

data/avatar/default/avatar19.webp

3857 Posts
Location -
Joined 2000-03-29
Plus, from what I remember in Physics, the dB halves for every doubling of distance from the sound source. So, just get a wireless KB/Mouse and a longer VGA cable if it gets too obnoxious.
 

 
------------------
Regards,
 
clutch

data/avatar/default/avatar16.webp

1615 Posts
Location -
Joined 2000-03-25
Are there any wireless mice out there that don't suck. I have used them before but they always seemed laggy and inaccurate. Are there any out there that would compare to the smoothness and accuracy of my intelli mouse explorer.

data/avatar/default/avatar40.webp

3087 Posts
Location -
Joined 2001-01-21
There will be some very loud fans or HSF like the Global Wins are supposedly loud.
Also, Swiftech has some gigantic coolers that are 50dB, so if you want a quiet pc, those ones are to be avoided. Tom's hardware guide has a good article on HSFs that includes the best cooling, the noise level, and some estimates of HSF prices.
Also, as Ive found out today, some HSFs will only run around their spec'd rpm if they are plugged into one of the PSU power connectors, and you'll have to get a cpu fan header to PSU power connection. I will be snagging one tomorrow, so that way my cpu can enjoy the cooling that every other component is enjoying.