Tom's hardware found...almost no noise

Edward Ng · Post by **Edward Ng** » Thu Jan 20, 2005 6:14 pm

That plus their ambient noise level is probably like Times Square levels.

mrzed · Post by **mrzed** » Thu Jan 20, 2005 6:15 pm

Tom's even describes some of the test conditions - 50cm, half the standard 1m distance usually quoted here or other reputable sources of noise information.

The funny thing is, maybe the barely audible statement is quite true. Human hearing is very attenuative (is that even a word?) meaning our sensitivity is very adaptable to low or high noise levels. When I imagine the Tom's test lab I think of a room filled with at least half a dozen systems running with standard (loud) Delta case fans, stock HSF's, 6800 Ultras, etc. Any moderately quiet system would be easily drowned out.

This may not be true, and they may all be recovering death metal bassists or something, but it just goes to show that when describing the noise of a component, any mention of the test equipment is questionable without a description of the test environment. That's why we're all here isn't it?

slipknottin · Post by **slipknottin** » Thu Jan 20, 2005 6:20 pm

There are all sorts of PC part reviews online where they author says 'this thing is absolutly noiseless'. Then they say its around ~35+ db.

How about this one for instance- http://www.hardcoreware.net/reviews/review-118-1.htm

"Now how's that for a Dead Silent PC? At ear level the only discernable noise being made is from the whisper-quiet Thermaltake PSU, thanks to the Seagate HDD we're using. It is pretty incredible walking into a room and knowing a P4 2.80 with a GF4 OC'd to the max is running, and you can't even tell until you turn the monitor on

"

And according to the author, the system measures 39.5 db.

Post by **MikeC** » Thu Jan 20, 2005 10:20 pm

slipknottin wrote:There are all sorts of PC part reviews online where they author says 'this thing is absolutly noiseless'. Then they say its around ~35+ db.

How about this one for instance- http://www.hardcoreware.net/reviews/review-118-1.htm

"..... you can't even tell until you turn the monitor on "

And according to the author, the system measures 39.5 db.

Actually, it was probably a fairly quiet rig they built. Only the PSU and the HDD made any noise, so my guess is maybe it hit 30 dBA/1m. But their meter might not have been capable of measuring low enough, so they did this:

To test the noise created by the PSU (and thus, the only noise being created by the entire rig), we used a decibel meter, placed directly above the it [psu] under full load. We took care not to place the microphone in front of the fan - we want to measure noise created by the fans, not by the wind blowing on the dB meter!

Many ways to mess up audio analysis...

meglamaniac · Post by **meglamaniac** » Fri Jan 21, 2005 1:18 am

The trouble with dB measurements, as shown here, is you need to know what you're doing to take them or they make no sense when compared to any test done to the proper standards (such as at SPCR).

Post by **MikeC** » Fri Jan 21, 2005 8:08 am

mrzed's comments about acoustic perceptions are probably right on the money regarding the THG review. The measurement technique was fine. Half meter is close to the distance specified by ISO7779 for seated operator position SPL measurement. The problem with that review lay in the subjective perception.

There's no way I would perceive any noise source that measured 40 dBA at half a meter to be quiet. This is around 35 dBA/1m -- give or take depending on other conditions. My ambient is typically 20 dBA or better, and it's easy for me to hear down to ~18 dBA. Perhpas THG's test ambient is >35 dBA. In which case, 40 dBA/.5m would seem close to inaudible...