How loud is 30dBa?

[Ruahrc]

I am big on case noise and ordered a 120mm Panaflo L1A with 69cfm at 30dBa. I am curious as to exactly how loud it is.

I own 80mm Panaflos that operate at 20dBa, very excellent quiet fans. I also got a blue orb that operates at 26dBa and have heard a 120mm Sunon fan that runs at 43dBa.

Now the 80mm Panaflo was nice and quiet, but the "26dBa" Blue orb was a foghorn! (So loud that I will not put it in my case due to noise) I swear it rivaled the noise of the 43dBa Sunon fan. Was the unit I recieved defective or something? The difference in noise between 20dBa and 26dBa was enourmous. This led to confusion as to exactly how loud the 30dBa Panaflo would actually be.

I heard the NoiseControl Silverado ran at 30dBa and you all compliment it's silence.

Please clear this up for me. Thanks

Ruahrc

[dos7]

not very loud to answer your question. if looks as though your fan's specs may be in question. Decibels are measure on a logarithmic scale. So if your fan is rated at 20db, then a fan rated at 30db would be 100 times louder, (10x10). a whipser is usually 20db,,while an f-14 tomcat at full afterburner from only several meters away is around 130 - 140 db,thousands of times louder you see, btw,,anything over 130db for more than a few seconds WILL be very painful and could result in permanent damage to your hearing.
so getting back to your question, 30db is not really all that loud, but apparently it is loud enough to bother you. Perhaps that fan you have is indeed louder than 30db,it's advertised rating, are you able to compare it to an identical unit so that you may see whether or not its a defective unit or if in fact the maker has given incorrect specs?

hope that gives you some ideas.


dos7

[This message has been edited by dos7 (edited 07-10-2001).]

[This message has been edited by dos7 (edited 07-10-2001).]

[OuTpaTienT]

Decibel comparison chart of common sounds:
The quietest sound you can hear: 0 dB
Whisper: 15 - 25 dB
Quiet background: about 35 dB
Normal home or office background: 40 - 60 dB
Normal speaking voice: 65 - 70 dB
Lawn mower: 90 dB
chainsaw: 100 dB
Live rock band: 120 - 150 dB
Jet aircraft taking off: 140 - 180 dB

[Szech]

Ruahrc, there are also different standardized methods of measuring the noise. I don't remember what they are, but I know that if some fan gets a 20dB rating on one method, it could well get a 26dB rating using a different method. So just the dBa rating alone isn't a good judge of how loud they will be without information on the testing methodology that they used. Do a search on Google, and I'm sure you can find out a lot about the different ways of measuring the noise. I have two of the 80mm L1A's, and they are nice!

BTW, here at work, we have a blast chamber that has two spouts. Out of one spout comes medical grade oxygen, out of the other comes hydrogen... 130dB. Think about that one for a second. You have to put ear plugs in, and put ear muffs over that.