Finally 0dB [inaudible] Sonata

goodie · Post by **goodie** » Sat Oct 06, 2007 7:18 am

Hello to all and great thanks to spcr team and forum members

After reading quite some reviews from spcr team and various experience from forum members, i finally managed to build up a completely silent computer. Here are some specs and details:

- Core2Duo E6300 1.86 GHz
- Gigabyte DS3
- 3GB ddr2
- Gigabyte 7600 GT passive cooling
- 2.5" Seagate Momentus 5400.3
- ZEN 300W
- Sunbeam Rheobus
- 2x Nexus 12cm

Few comments:
- cpu cooling: i use Thermaltake Sonic Tower with 2 Nexus fans which are regulated with Sunbeam Rheobus, and at around 5 or 6V they are completely inaudible. First i had one fan at back for exhaust and one in front for intake, but the frontal one did absolutely nothing for cooling down the temperatures, so i put it between the towers where it is very effective.

- no 3.5" hdd is quiet enough, so i got Momentus 5400.3 and put it in a plastic box (the big white box at the bottom of case) stuffed with a lot of plastelin (non drying modelling clay), similar to viewtopic.php?t=22839&highlight=clay but i used a videocassete box, because i couldnt get PSP box. Hdd is inaudible from 20-30 cm away and even though it is completely closed, the temperature still doesnt go higher than 33 deg, usually it is even less.

- few words about ZEN: i had my doubts whether 300W will be enough when OCing and connecting more hardware to it, but when OCed C2D to 3.15 GHz, adding two more 3.5" HDD, DVDRW, set 3 fans and 2 LEDs on 12V and stressed my comp with 3DMark06 and some other software it had no problems with stability at all.

tehfire · Post by **tehfire** » Sat Oct 06, 2007 8:19 am

Probably not 0dB, but extremely quiet I bet. Nicely done.

AuraAllan · Post by **AuraAllan** » Sat Oct 06, 2007 8:20 am

Cant be 0db but very nice indeed.

goodie · Post by **goodie** » Sat Oct 06, 2007 10:23 am

Thanks, what I meant was that it is completely inaudible from 1m away, so this would mean 0dB at 1m, no?

dhanson865 · Post by **dhanson865** » Sat Oct 06, 2007 10:55 am

No, if the room you are in has background noise of 20dB and the computer is putting out 15dB you won't be able to distinguish the noise from 1 meter away but the noise is still there.

Unless you know the dB for ambient noise 1 meter away from your PC you don't know how much noise the PC can make and still seem quiet.

Think of it this way. If you have a flashlight in a dark room you can see it easily. If you take it outside into the brightest sunlight in the middle of summer the flashlight will seem dim.

In neither case do you have 0 decibels or 0 candle power. The noise or light will be the same and measure above 0 no matter what you compare them to.

goodie · Post by **goodie** » Sat Oct 06, 2007 11:13 am

I understand, and i completely agree for daytime, but during the night, since i dont live in a city, it gets very quiet, there is no noise at all (that i can hear) if it isnt raining/windy/car passing etc., so i assumed that means that background noise is 0dB. Maybe i should get dB meter to measure the noise during the night to see if there really is no noise or am i just half deaf

djkest · Post by **djkest** » Sat Oct 06, 2007 12:16 pm

I believe a quiet room gets down to about 20 dB MAYBE 15, but unlikely. I think Mike C has an ambient noise around 20 dB at his testing lab. That is on the threshold of human hearing, I believe.

To get quieter than that you need an Anechoic chamber.

Inaudible, probably. 0 dB? Probably not.

goodie · Post by **goodie** » Sat Oct 06, 2007 12:21 pm

I see. Then sorry for misleading topic title.

BillTodd · Post by **BillTodd** » Sat Oct 06, 2007 12:48 pm

Here we go again....

0dB is simply a ratio of 1:1 [Mod: a ratio of what to what?]
[edit:] A ratio of any number (usually representing signal power or level) to another. Bels are a useful means of scaling a number with huge range into something easier to handle (e.g. 0 to 12Bels = 1 to 1,000,000).

To make sense as a measurement of noise or signal level, you HAVE to add an extra letter to indicate the reference level.

Typically, audio level measurements are reference to the so called 'threshold of hearing' and weighted (i.e. filtered to better match the audio reponce of the ear - see http://en.wikipedia.org/wiki/A-weighted) then the given the desination dBA.

So,

0dBA is as quiet as you can hear (i.e. a 1kHz sine wave with a sound pressure of 0.00002 Pascal or, roughly, the ear drum moving a distance about the same as the 'diameter' of a hydrogen molecule )

120dBA is the 'threshold of pain'

150dBA - noise of Saturn V take-off = fatal internal injuries.

more here:http://en.wikipedia.org/wiki/Noise_level

Krillepille · Post by **Krillepille** » Sun Oct 07, 2007 3:07 am

Really nice! I liked it!