SPCR

How far away does a psu have to be to not be heard? I have my psu at least 6 ft away...will I still hear it?
If its pointed to the left or right or away from me does it matter?

i thought i need a fanless psu..but then i read article aobut spcr computer that under the desk was pretty much silent..and that was 20 decibels... if 20 decibels are that easily covered up..than i should just get a corsair hx520...insteaf of getting a fanless one. i can put my computer at least 6ft away...

Personally, I think fanless PSUs are really only useful in very specific cases. Do you use a 3.5" hard drive, or more than one even? If so, that probably will make more noise than the HX520. The best 3.5" hard drives sit around 20-21db idle and 22-24db seeking. I don't believe a good fanned PSU like the Corsair will be noticeable. Especially if it's under your desk.

22db is pretty f%$cking quiet.

Better to specify the brand and model of the PSU. 22dB is not much but it doesn't really say a lot about the sound from the PSU.

I mean, 22 "Thermaltake-dB" are quite a lot..

Half as loud as 25dB and twice as loud as 19dB.

Vicotnik wrote: I mean, 22 "Thermaltake-dB" are quite a lot..

I would say that the average fan or psu that labels itself as 22dB falls somewhere between loud droning and an all out scream.

To answer your question, though, distance can make a big difference in volume. Isn't the relationship between sound power and distance something like d^-4? In other words, distance makes things quieter quickly. Removing direct paths between you and the noise source makes a difference too.

jhhoffma wrote:Half as loud as 25dB and twice as loud as 19dB.

Perceived loudness doubles every 10dB; it's sound intensity that doubles every 3dB.

Isn't the relationship between sound power and distance something like d^-4?

I think you mean sound pressure, sound power does not decrease with distance:

http://en.wikipedia.org/wiki/Sound_power

Sound power is neither room dependent nor distance dependent, like it is with sound pressure or sound intensity. Sound power belongs strictly to the sound source. There is no decrease of power with distance.

http://en.wikipedia.org/wiki/Sound_pressure

When measuring the sound created by an object, it is important to measure the distance from the object as well, since the SPL decreases in distance from a point source with 1/r (and not with 1/r2, like sound intensity).

jaganath wrote:Perceived loudness doubles every 10dB; it's sound intensity that doubles every 3dB.

That too....

22 db is the sound a manufacturer makes when it lies to the public.

I dont think anything has gotten that rating on SPCR besides like a 120 nexus at 5 volts. if a psu was 22db, it would be really really really quiet. fit a silence enthusiast's desires to the T.

whatever T is.

hm.

~El~Jefe~ wrote:I dont think anything has gotten that rating on SPCR besides like a 120 nexus at 5 volts. if a psu was 22db, it would be really really really quiet. fit a silence enthusiast's desires to the T.

Look at the table at the bottom of this page and read some of the latest SPCR PSU reviews.

yeah those. thanks forthe link, it is a good link.

problem is that in a warm room with slow moving fans in a case or just 1 in my case, a x1900 allinwonder card, 2 gigs ram, 4200 dual core, on 24/7, those psu's ramp up no matter what anyone claims on here. I run water cooling currently so that doesnt happen easily, but my setup is a bit $$ and annoying to deal with after a while. Even with my amd64 754 socket 2.0ghz chip on via k8t800 pro board (the least power using usable chipset in the world possibly), along with a 9800 pro aiw card, I could not get any psu to not ramp up. that is really minimal in terms of power requirements too. Back then I didnt have my zalman blue tower thing though, so maybe it could have worked.

mostly, these things operate at the 28 ish decibel when you play a game or what not. gaming systems, and mine is actually conservative (the all in wonder is half ram and slightly underclocked, the cpu is only 2.2 ghz) this never seems to work for me.

I have never had a system ever no matter what I do design and case wise that doesnt have the psu ramping up randomly. I have yet to try out this year's batches as my 350 phantom is just sickness in a can, maybe I would pleasantly surprised.

I know that when I go the "r600" all in wonder probably in the summer or fall, I will have to contend with a different psu that can provide even more stable high end amperage on its lines. I dread getting a fanned 500 watter, so rediculous to think of 500 watts to play a freakin direct x 10 game!!!

There are different ways of getting that 22 db. Some measure-then subtract ambient noise. Some measure at 1 m,some furthur or closer.

By common standards,22 db from a 120 mm fan is about what you'd get at 1500 rpm, but if it's measured in the strictest way-22 db may be the reading from the same fan at 600 rpm. I tend to look a bit more at rpm than db as there's no vague standards for rpm

~El~Jefe~ wrote:22 db is the sound a manufacturer makes when it lies to the public.

A quality line...

Is significantly dependent on the spectrum distribution of the sound. A weighting on dB scale does not produce a very accurate "sound loudness" estimates (perceptual scale) for human hearing on all possible sounds.

The best way to find how loud a particular 22 dB(A) sound sounds like, is to listen to it.

cjmuk wrote:

~El~Jefe~ wrote:22 db is the sound a manufacturer makes when it lies to the public.

A quality line...

I thought that was pretty damn funny too. Nice one!

hey, thanks!

most often my lines piss people off. Glad to please someone on here finally!


I dare say that if things were actually 22db, we would not hear it over our typing on a quiet keyboard.

belkincp wrote:I have my psu at least 6 ft away...will I still hear it?

The Blues Brothers wrote:Jake: How often does the train go by?
Elwood: So often that you won't even notice it.

nice line