Are the silent recommendations reproducible?

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386-sx-33
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Are the silent recommendations reproducible?

Post by 386-sx-33 » Fri Jun 22, 2007 10:36 am

I assume SPCR reviews are all done in a unbiased and professional way.
But are the results reproducible outside the SPCR lab?
Can 'extremely quiet' in the SPCR lab mean 'annoying' in my PC?
Every PC is different. Different case, different placement of fans, psu, (number of) drives, cabling etc etc.
Can a case layout make such a difference that sound temp reading are unrealistic in some situations?
I find this hard to explain but what I mean is that a ultra quiet fan is very loud when it's sound is pushed through a flute.

As the placement of fans an impact on sound.
For example: Does a case fan that sucks air from near a noisy component also transfers the sound outside?
If yes the position of the fans may be of the same impact as the actual noise of the fan.
I have a stacker case and it has mountings for fans on many places.
But none on the bottom. I've been thinking about the following:
(Only) use a outtake fan on the bottom of the case.
My case is standing on a carpet so I think that will dampen the sound.
The air/sound pushed out from the side/back will reflect on the walls.

Any thoughts on this please.....

cmthomson
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Post by cmthomson » Fri Jun 22, 2007 1:10 pm

The general thrust of SPCR recommendations is for components that create the least noise in the first place, with much less emphasis on damping noise (except of course for hard disk mounting arrangements).

That said, the case definitely makes a difference. For example, a P180 has lots of damping features and virtually no resonance (the glaring exception being the lower PS/HD chamber, which will resonate if you put a noisy fan in it). By contrast, a cheap aluminum case will resonate like crazy and amplify many irritating noises...

jaganath
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Post by jaganath » Fri Jun 22, 2007 1:11 pm

a ultra quiet fan is very loud when it's sound is pushed through a flute.
:?:
you mean the musical instrument, the flute? :?
Does a case fan that sucks air from near a noisy component also transfers the sound outside?
no, the case fan does not literally "suck" the sound outside. however the fan hole allows (direct & reflected) sound to escape. if this is a serious source of noise you can use ducts and baffles to minimise it.
(Only) use a outtake fan on the bottom of the case.
it would make more sense to have an intake on the bottom (Bluefront did this a long time ago), however you have to filter it because of carpet dust.
The air/sound pushed out from the side/back will reflect on the walls.
1) you can treat the walls
2) you can reduce sound produced so less is reflected.

386-sx-33
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Post by 386-sx-33 » Fri Jun 22, 2007 1:19 pm

jaganath wrote:
a ultra quiet fan is very loud when it's sound is pushed through a flute.
:?:
you mean the musical instrument, the flute? :?
Yep. Not that I'm going to do that ofcourse....
I just trying to give an example, a bad one so it seems, that even a ultra quiet fan can produce lots of noise if the situation (case layout) is bad.

386-sx-33
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Post by 386-sx-33 » Fri Jun 22, 2007 1:21 pm

386-sx-33 wrote:
jaganath wrote:
a ultra quiet fan is very loud when it's sound is pushed through a flute.
:?:
you mean the musical instrument, the flute? :?
Yep. Not that I'm going to do that ofcourse....
I just trying to give an example, a bad one so it seems, that even a ultra quiet fan can produce lots of noise if the situation (case layout) is bad.
1) you can treat the walls
Not sure why but my wife is starting to swing with teh baseball bat again :wink:

386-sx-33
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Post by 386-sx-33 » Fri Jun 22, 2007 1:26 pm

cmthomson wrote: By contrast, a cheap aluminum case will resonate like crazy and amplify many irritating noises...
Does my Cooler Master Stacker case fall in that category.
It wasn't exactly cheap, but aluminium doesn't feel so heavy/strong.
Maybe a old fashioned steel case is a better choice.
I chose that Stacker because of it's space and many vent holes.

Aris
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Post by Aris » Fri Jun 22, 2007 5:02 pm

you have to be really carefull when you start putting fans on the bottom of your case, or anywhere else where you will have a solid surface too close to the fan. I think bluefront tested it out and figured you need to have a minimum of around 40mm clearance in front of a fan or it will generate more noise.

and yes the SPCR recommendations are completely reproducible. If anything, if you followed their reviews to the letter your system will more than likely end up being quieter (subjectivly) than what MikeC recorded, because not many people have rooms with ambient noise levels below 20dba like at mikes house.

vortex222
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Post by vortex222 » Fri Jun 22, 2007 6:28 pm

most of the recommended fans will produce audible noise if driven at 12 volts. The trick is to balance noise with cooling power, and what you find an acceptable temp to run your computer at.

Having high quality heat sinks and cooler running components makes that a snap.

A good base of PSU is the Corsair HX series. They are exceptional in almost any circumstance. And after that possibly a ThermalRight tower cpu heatsink or Scyth Ninja tower heatsink with one of the recommended 12 CM fans at low voltage or even thermally controlled.

Look to remove restrictive fan grills on the case and load them with one of the recommended fans of the appropriate size. (undervolted and possibly thermally controlled)

After that, look to replace any Chipset fans with one of the many passive Chipset coolers available these days... Thermalright makes a few excellent options.

Just that alone is a huge basis for a PC that is quieter then 99% of produced computers on the market.

My latest computer upgrades have been based mostly on the recommended list, and a bit of handy use of a dremel. My computer is far below the ambient noise of the room.

My computer isnt as quiet as most of the hardcore SPCR peeps, but at this point its good enough for me.

(the only path i have is to replace hardrives.. Costly at this point)

386-sx-33
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Post by 386-sx-33 » Fri Jun 22, 2007 8:05 pm

Aris wrote:you have to be really carefull when you start putting fans on the bottom of your case, or anywhere else where you will have a solid surface too close to the fan. I think bluefront tested it out and figured you need to have a minimum of around 40mm clearance in front of a fan or it will generate more noise.

and yes the SPCR recommendations are completely reproducible. If anything, if you followed their reviews to the letter your system will more than likely end up being quieter (subjectivly) than what MikeC recorded, because not many people have rooms with ambient noise levels below 20dba like at mikes house.
Mmmm, then my PC placement is completely wrong.
My PC is my, drumroll, PC room. Without going into boring details at the back and right side of it are wall. At the bottom carpet.
At the top and left side is a CAD table. Not one of those tables with tiny legs but a big steel colum in the middle with the stuff to adjust height and angle.
So I fear that colum and top also reflect sound.
Because of cabling the space where I can place my PC is limited.
The minimum width between wall and table is 90cm.
I opeed for a outtake fan on the bottom because that the only soft surface. (carpet)
The case is on 4cm high wheels.

So perhaps an outtake fan at the bottom is the least worse option?
What's your opinion on that?

386-sx-33
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Post by 386-sx-33 » Fri Jun 22, 2007 8:27 pm

@vortex222
I don't expect my case to be quiet but just more silent.
I hate the sound of the fans/airflow. That can be fixed I think.
My Raptor drives can't be silenced and I'm not prepared to replace them with something else.

I'll certainly take your PSU recommendation in consideration. It gets good reviews and is reasonably cheap too.
Corsair CMPSU-520HXEU and Corsair CMPSU-620HXEU, is what I can find in the shops.
Slightly different name than used in the SPCR review. I hope it's the same one.
One of said good things of this PSU is the fact that is sucks heat away from the CPU.
Does that conflict when using a duct/tunnel for CPU cooling?
Speaking about a duct... What about a duct from the CPU to the PSU?

I probably buy a Asus P4K series mobo that has a passive cooled chipset and fan control

Aris
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Post by Aris » Fri Jun 22, 2007 10:42 pm

biggest things to keep noise down:

1. never have any fan running over 1k rpm, preferably under 800rpm

2. switch to 2.5" single platter 5400rpm drives if you can, and then enclose them in somthing like this: http://www.newegg.com/Product/Product.a ... 6817984003

if you follow those 2 rules, you will be hard pressed to hear your computer.

the biggest challenge with getting your fans to run that slow without your system burning up is to use lower power quality components. Mobile on The Desktop (MoTD) is the easiest way to drop power requirements while maintaining adequit performance. The merom Core 2 Duo chips have a TDP i think of only 37watts. thats around half as much as the conroe desktop C2D's. The performance difference between the two at the same clock rate isnt that huge.

Use high effeciency PSU's. the higher the effeciency at your system's current load, the less heat its dumping into your enclosure. If you can get your system power requirements low enough you can switch to external passive brick adapters to completely remove all heat your psu produces from your case. You can use a seperate 12v ac/dc adapter brick to power just your video card if you require more powerfull graphics.
Even if you dont use external power adapters, you should thermally seperate your PSU area from the rest of your case. You do this, and keep your system power requirements low and your psu fan should never ramp up.

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