how much difference is 6 decibels for a case fan?
Home | Reviews and Features | Special Reports | Forums |

Results 1 to 11 of 11

Thread: how much difference is 6 decibels for a case fan?

  1. #1
    Join Date
    May 2000
    Posts
    502

    how much difference is 6 decibels for a case fan?

    setting up a new system.

    I've been using 92" Sunon case fans for my system, but I'd like to go quieter this time around.

    I've looked at the 92" Panaflo and its rated at 27dba. as opposed to the Sunon's 33dba.

    However it will pump out a little less air at 42.7CFM as compared to Sunon's 44CFM. (not much though)

    I'm guessing that the 6dba difference is quite noticeable, and offsets the 1.3 CFM diff. in airflow.

    anyone confirm...

    Thanks.

    ------------------
    ...everyone should taste a little bitterness in their lives....

    [This message has been edited by Chairman Mao (edited 03-12-2001).]
    ...everyone should taste a little bitterness in their lives....

  2. #2
    Join Date
    Jan 2000
    Location
    USA
    Posts
    1,684
    I'm reaching back here, but I believe that a difference of 3db = half as loud, so 6db difference would make it 1/4 as loud. If it was the only source of sound in a room, I think it would make a pretty big difference.
    Free advice, and worth every penny.

  3. #3
    Join Date
    Jan 1999
    Posts
    1,424
    RoadWarrior, I think you've got that backwards.

    A +3dB difference means the sound intesity is twice as loud. And thus a +6dB difference would be 4x as loud.

    For reference, a difference of 10dB is ten times as loud. So 40dB is 10x as loud as 30dB.



    ------------------
    This signature space FOR SALE
    This signature space FOR SALE

  4. #4
    Join Date
    Dec 1998
    Location
    Grand Haven, Michigan, USA
    Posts
    11,332
    There is also a formula for figuring out adding db tegether but it pritty much works out to two sounds at 27db=30db or twice as loud.

    The only thing is PanaFlos are not speed sensing and generally do not ship with plugs attached. Minor issues, but don't be supprised. They are also brittl. I hit one with a small tape messure and a fin snapped off (while running). Supprisingly it does not vibrate. They are very quiet. The 80mm is even more quet and if you take 4 of them, you will run at 100CFM for only 27db total (they run at 21db each).

    ------------------
    The COMPUTER is your FRIEND!
    Happiness is manditory.
    AMD Phenom II x4 945 3Ghz | ASUS M4A77TD | 2X WD 1TB SATA 2 hard drive | 2x2GB Corsair XMS3 | nVidia GeForce 8800 GTS | ATI TV Wonder Theater Pro 550 | Antec P-160 case | Antec 650w Earth Watts | LG Blu-ray Super Drive | LG DVD RW | Windows 7 Pro

  5. #5
    Join Date
    Sep 1999
    Posts
    766
    every 10db is ten times as loud.. ie 20db is ten times as loud as 10db not double it...

  6. #6
    Join Date
    Dec 1998
    Location
    Grand Haven, Michigan, USA
    Posts
    11,332
    That means for example the GlobalWin FOP38 is 10 times louder than the FOP32-1 I have (and I don't even like the noise it makes. That also means the Delta Black Label 38CFM 60mm fan that the FOP38 uses is 100 times louder than the 92mm PanaFlo L1A low noise fan. that generates 43CFM airflow. That is just insain. Why is ducting not as popular?

    ------------------
    The COMPUTER is your FRIEND!
    Happiness is manditory.
    AMD Phenom II x4 945 3Ghz | ASUS M4A77TD | 2X WD 1TB SATA 2 hard drive | 2x2GB Corsair XMS3 | nVidia GeForce 8800 GTS | ATI TV Wonder Theater Pro 550 | Antec P-160 case | Antec 650w Earth Watts | LG Blu-ray Super Drive | LG DVD RW | Windows 7 Pro

  7. #7
    Join Date
    Nov 1999
    Posts
    344
    Are you sure the noise levels of the fans were measured in the exact same conditions(acoustics, distance, etc)? Otherwise the figures have zero comparative value.

    ------------------
    "No doubt the truth, as usual, would be somewhere between the extremes" -Arthur C Clarke
    "No doubt the truth, as usual, would be somewhere between the extremes" -Arthur C Clarke

  8. #8
    Join Date
    Oct 1999
    Location
    Hamar, Norway
    Posts
    1,187
    MadCat : I've read yours and RoadWarriors posts twenty times now, but I still can't see how he is wrong and you are right. You are both saying the same thing.

    ------------------
    Carpe noctem!
    Carpe noctem!

  9. #9
    Join Date
    Jan 2000
    Location
    USA
    Posts
    1,684
    Thanks. I probably could have phrased it better. I think he is looking for -3db and -6db, where what I said was 3db difference and 6db difference.

    I do agree that comparing manufacturer claims is bound to be an apples to oranges situation. There are probably OSHA type testing standards, which many of the companies make efforts to comply with, but unless all the testing is done by an independent third party, there is a good chance that large differences in results exist.
    Free advice, and worth every penny.

  10. #10
    Join Date
    Feb 1999
    Location
    Newcastle Upon Tyne, England
    Posts
    1,077
    The Decibel scale is logarithmic (spelling?) not linear. A 10Db increase increase is equivalent to a doubling of the sound intensity/level .

  11. #11
    Join Date
    Oct 1999
    Location
    Hamar, Norway
    Posts
    1,187
    All I know for sure is that -3db is a reduction of 50% in sound intensity (been doing a bit of sub enclosure designing)

    ------------------
    Carpe noctem!
    Carpe noctem!

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •