Total Fan Noise - how to calculate ??

Discussion in 'PC Hardware' started by Ken Roberts, Apr 21, 2005.

  1. Ken Roberts

    Ken Roberts Guest

    For example, if I have the following:

    5 case fans - 28 dBA
    1 CPU fan - 15 dBA
    1 PSU fan - 23 dBA
    1 Video Card fan - 12 dBA
    ------------------------------------------
    Total = 190 dBA

    Now, I am certain that you cannot calculate the amount of noise you
    will hear by adding all the fan's dBA rating together. I am also sure
    it would be an extremely complex formuyla to calculate, because there
    are so many variables (placement of fans, distance from user's ears,
    vibration, etc).

    What I am wondering though, is if there is a very general ballpark way
    to estimate how much noise a system will create. TIA
     
    Ken Roberts, Apr 21, 2005
    #1
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  2. Ken Roberts

    Al Dykes Guest

    In article <>, Ken Roberts <> wrote:
    >For example, if I have the following:
    >
    >5 case fans - 28 dBA
    >1 CPU fan - 15 dBA
    >1 PSU fan - 23 dBA
    >1 Video Card fan - 12 dBA
    >------------------------------------------
    >Total = 190 dBA
    >
    >Now, I am certain that you cannot calculate the amount of noise you
    >will hear by adding all the fan's dBA rating together. I am also sure
    >it would be an extremely complex formuyla to calculate, because there
    >are so many variables (placement of fans, distance from user's ears,
    >vibration, etc).
    >
    >What I am wondering though, is if there is a very general ballpark way
    >to estimate how much noise a system will create. TIA



    Google for "how to add dba" came up with this...

    http://www.overclockers.com/articles607/

    To simplify, if you have two 28dBA fans, combined they are 31dBA. Do
    that again (2x2 fans) and you're up to 34dBA, so your 5 case fans are
    about 35dBA. The rest of the fans, combined bring you up to maybe
    37dBA.

    It'll generate high numbers (ie lower perceived sound) because, for
    example, given identical fans, one moving air into the case and one
    exhaustiong air out, the exhaust fan will be a bit louder.

    Nobody needs 5 case fans for anything like a standard desktop PC. It
    the're not set up right they are fighting each other. One on and one
    out should do it.
    --
    a d y k e s @ p a n i x . c o m

    Don't blame me. I voted for Gore.
     
    Al Dykes, Apr 21, 2005
    #2
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  3. Ken Roberts

    Matt Guest

    David Maynard wrote:

    > dB = 10 * log 10 (power in W/m 2 ) + 120, to get the dB(A) sound level


    W/(m^2) is a unit of intensity, not power.
     
    Matt, Apr 21, 2005
    #3
  4. Ken Roberts

    Patrick Guest

    > Sensitivity also changes with the volume, which is what the 'loudness'
    > control on stereos is for: to boost them when the volume level is turned
    > down.


    To boost what? Does the loudness control do more than increase/decrease
    the volume?
     
    Patrick, Apr 22, 2005
    #4
  5. Ken Roberts

    Matt Guest

    David Maynard wrote:

    > Sensitivity also changes with the volume, which is what the 'loudness'
    > control on stereos is for: to boost them when the volume level is turned
    > down.


    To boost what? Does the loudness control do more than increase/decrease
    the volume?
     
    Matt, Apr 22, 2005
    #5
  6. Ken Roberts

    Matt Guest

    David Maynard wrote:

    > Sensitivity also changes with the volume, which is what the 'loudness'
    > control on stereos is for: to boost them when the volume level is turned
    > down.


    To boost what? Does the loudness control do more than increase/decrease
    the volume?
     
    Matt, Apr 22, 2005
    #6
  7. Ken Roberts

    Matt Guest

    David Maynard wrote:

    > Sensitivity also changes with the volume, which is what the 'loudness'
    > control on stereos is for: to boost them when the volume level is turned
    > down.


    To boost what? Does the loudness control do more than increase/decrease
    the volume?
     
    Matt, Apr 22, 2005
    #7
  8. Ken Roberts

    Matt Guest

    whoops

    sorry, having a little trouble with my news server ...
     
    Matt, Apr 22, 2005
    #8
  9. Ken Roberts

    Al Smith Guest

    >> Sensitivity also changes with the volume, which is what the 'loudness' control on stereos is for: to boost them when the volume level is turned down.
    >
    >
    > To boost what? Does the loudness control do more than increase/decrease the volume?


    It exaggerates the base and treble, fooling your ear into thinking
    that you have the volume higher than it actual is.
     
    Al Smith, Apr 22, 2005
    #9
  10. Ken Roberts

    ric Guest

    Re: whoops

    Matt wrote:

    > sorry, having a little trouble with my news server ...


    Are you with HOTMAIL? They had a major burp at 1421 ET.
     
    ric, Apr 23, 2005
    #10
  11. Ken Roberts

    sbb78247 Guest

    John Doe wrote:
    > Matt <> wrote:
    >
    > (for the third time)
    >
    >> To boost what? Does the loudness control do more than
    >> increase/decrease the volume?

    >
    > Besides double and triple replies to the same post, your posts
    > have been showing up in duplicate and triplicate for weeks. Once
    > is plenty.
    >


    God you are a bitchy little thing
     
    sbb78247, May 5, 2005
    #11
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