silencing norco 4220 with fake hdd blocks

Enclosures and acoustic damping to help quiet them.

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publicENEMY
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Joined: Thu Mar 08, 2012 6:49 pm

silencing norco 4220 with fake hdd blocks

Post by publicENEMY » Mon Apr 09, 2012 1:38 am

Hi,

Ive build a storage server using norco 4220 case.everything inside the case is very quiet. the only sound i can hear is the wooosh my 3 noctua pf12 120mm fans.

i plan to reduce the woosh sound my fans by soundproofing(blocking the sound) and/or sound diffusing. the sound is a low frequency noise and can be reduce by putting dense mass in the front of the case. i intend to do this by inserting dense mass material in unused hdd tray. by constructing a hdd size hollow box, i can insert dense material inside the box. here are the list of material with its density http://en.wikipedia.org/wiki/List_of_el ... by_density.

i have 2 problem
1. constructing fake hdd blocks(hollow or solid)
2. optimal material(cheap and good) to be use for reducing the noise

heres what i found
1. i tried constructing hollow hdd blocks by using acrylic, but acrylic is too damn expensive.
2. i tried constructing hollow hdd blocks by plastic mold but the price for small quantity is too dam expensive.
3. cement and plaster of paris as solid blocks is easily breaks.
4. i thought of using zinc plates but this requires a lot of cutting by myself. plus, i cant figure out how to joint the zinc edges.

any suggestion?

SoulWager
Posts: 19
Joined: Tue Apr 03, 2012 6:57 am

Re: silencing norco 4220 with fake hdd blocks

Post by SoulWager » Mon Apr 09, 2012 2:23 am

Is the low frequency noise from the airflow or from vibration conducted through the mounting hardware? You're probably better off reducing both air restrictions and fan speed, rather than adding damping. If you do go the damping route, avoid hard materials, as they'll just bounce the sound around rather than absorb it, open cell foam is ideal.

publicENEMY
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Joined: Thu Mar 08, 2012 6:49 pm

Re: silencing norco 4220 with fake hdd blocks

Post by publicENEMY » Mon Apr 09, 2012 3:55 am

i believe the noise is not conducted through mounting hardware. noctua provided rubber gasket for their fans. most likely the noise is from air restriction because of dense wiring near air intake(unavoidable). its true that using hard material will bounce back noise, but that is actually my intention(blocking the noise). the problem with foam is that it is unsuitable for dampening low frequency noise.

nevertheless, if you know of a foam that can damp low frequency noise, suggest me one. as long as the noise can be reduce.

thanks.

Wibla
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Re: silencing norco 4220 with fake hdd blocks

Post by Wibla » Mon Apr 09, 2012 5:18 am

you can close the trays you dont use, there's a mechanism for that on every tray...

ntavlas
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Re: silencing norco 4220 with fake hdd blocks

Post by ntavlas » Mon Apr 09, 2012 9:01 am

A few old hard drives could make a pretty effective sound barrier and would require no further work to fit in.

publicENEMY
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Re: silencing norco 4220 with fake hdd blocks

Post by publicENEMY » Mon Apr 09, 2012 3:44 pm

ntavlas wrote:A few old hard drives could make a pretty effective sound barrier and would require no further work to fit in.
exactly. unfortunately, i dont have 19 unuseable old hard drive.
Wibla wrote:you can close the trays you dont use, there's a mechanism for that on every tray...
thats the first thing i did. the noise still leaks.

ntavlas
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Re: silencing norco 4220 with fake hdd blocks

Post by ntavlas » Tue Apr 10, 2012 12:36 am

exactly. unfortunately, i dont have 19 unuseable old hard drive.
How many hard drives have you got installed then? It sounds as if there`s only one (perhaps along with a 2.5 inch boot drive?). You could dial down the speed of the fans producing most of the noise as long as temperatures remain satisfactory. Three intake fans running at full speed (12000rpm for the Noctuas if I`m not mistaken) is overkill if you`ve only got a handful of drives installed. Are any exhaust fans installed?

publicENEMY
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Joined: Thu Mar 08, 2012 6:49 pm

Re: silencing norco 4220 with fake hdd blocks

Post by publicENEMY » Tue Apr 10, 2012 4:05 am

i got 1 hdd in 20 tray hdd. yes, 3 noctua full speed and 2 arctic cooling pwm(lowest speed most of the time).

it wasnt for me, so it must be install and forget. i cant expect the end user to manually dial down fan speed.

thanks.

ntavlas
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Re: silencing norco 4220 with fake hdd blocks

Post by ntavlas » Tue Apr 10, 2012 11:49 am

Keeping the fans at 900-1000rpm could achieve just as much as filling the front of the case with blocks and would still be enough to cool any drives installed (even 20 if you add a forth fan). Don`t the Noctua fans come with LNA and ULNA adapters? You could use those to permanently slow down the fans, no further user intervention will be required.

If whoever uses this computer doesn`t plan to add more than 6-8 drives (2 per fan) even 600 rpm would be plenty. This should make the front fans almost, if not completely, inaudible.


If you really have to go the soundproofing route, perhaps you should consider bitumen sheets. I would add a single layer to the sides and top and multiple layers to the front.

publicENEMY
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Joined: Thu Mar 08, 2012 6:49 pm

Re: silencing norco 4220 with fake hdd blocks

Post by publicENEMY » Tue Apr 10, 2012 10:10 pm

ntavlas wrote:Keeping the fans at 900-1000rpm could achieve just as much as filling the front of the case with blocks and would still be enough to cool any drives installed (even 20 if you add a forth fan). Don`t the Noctua fans come with LNA and ULNA adapters? You could use those to permanently slow down the fans, no further user intervention will be required.

If whoever uses this computer doesn`t plan to add more than 6-8 drives (2 per fan) even 600 rpm would be plenty. This should make the front fans almost, if not completely, inaudible.


If you really have to go the soundproofing route, perhaps you should consider bitumen sheets. I would add a single layer to the sides and top and multiple layers to the front.
actually, i did use bitumin sheets at top and sides of the case. it does make a difference. unfortunately i cant put bitumin sheets in front of the case. while you barely hear the noise from the top and sides, noticeable noise can be heard from the front. any other idea?

as for reducing the fans, my country is hot and during low frequency usage, hdd temp would reach 40c+. this is already green drives. i cant get any cooler and quieter drives than this.

thanks.

Wibla
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Re: silencing norco 4220 with fake hdd blocks

Post by Wibla » Wed Apr 11, 2012 4:51 am

Build a silencer case around it?

This is a rackmount server, expecting utter silence is futile...

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