Is sound damping very useful to reduce noise (Sileo 500)?

netmask254 · Post by **netmask254** » Mon Aug 10, 2009 2:07 am

After read its review (http://www.silentpcreview.com/article946-page5.html), I was very surprised by the SPL recordings.

Its two stock fans has a SPL of 12dB SPL at 7V. But in IGP idle mode, the noise level can still be as low as only 15dB, which means that the combined SPL of the CPU fan, PSU fan & hard disk is only 12dB (12+12=15), how is it achieved? Personally I quite appreciate the SPL in idle status (I will not care about noise when gaming) & with a moderate VGA card (which can be passively cooled or with a very low speed fan).

The biggest difference between S500 and other cases is its damping material. Is it generally very useful to reduce the noise level of components inside the box?

I did a very unsuccessful mod of damping in last summer, it doesn't result perceivable difference to me. What's worse, it is not removable after pasting to the side panel. How about you guys?

pcy · Post by **pcy** » Mon Aug 10, 2009 10:31 am

Hi,

I'd say that damping material is not particulalrly important/effective but it all depands what point you are starting from.

If the case rattles or vibration from any of the PC components can reach the main case shell, then you have to stop that from happening, and damping material can paly a role in that.

If the HDs interact with eachother (creating a beat frequency) or the vibrations from them can reach the case shell, as low frequencey supension system for each individual HD is probably the best answer.

If the PSU vibrations affect the case shell it should be mounted in a soft foam bed - the standard four scews are an invitaion to transmit vibrations.

Once you have addressed these issues the case shell will be accoustically isoltaed from all the noise and vibration sources in the PC. The, all the remaining noise coming from the case should be airbourne, and the source should be the cooling fans (CPU, PSU or case ventilation) or the HDs.

The best way to reduce the noise from the cooling fans is to optimize airflow through the case , or (if it ramps up more than is necessary) replace the PSU or PSU fan.

Accoustic absorbant material (not damping material) may help reduce HD noise.

Peter

jessekopelman · Post by **jessekopelman** » Mon Aug 10, 2009 2:14 pm

Is dampening very useful in reducing PC noise?
No.

Is it useful at all in reducing PC noise?
Maybe.

Do people waste too much time thinking about it when they should probably just go ahead and suspend their HDD or break the bank on an SSD?
Yes.

echn111 · Post by **echn111** » Tue Aug 11, 2009 1:08 pm

Accoustic absorbant material / dampening does help to reduce PC noise. BTW: I'm not particularily aware of the differences between the two terms and use them interchangably. And all my dampening material is expected to be reasonably accoustic absorbant material anyway; it's not like I'm going to use aluminum or tin to dampen my case.

However the actual 'perceived' benefit will vary depending on your circumstances. If you've got a noisy PC, don't expect it to help much. If your noisy case vibrates, it can help a bit, but it's still going to be noisy. But if you've already got your quiet HDD isolated, you're already setup with SSD, you're running your CPU cooler passive and all your fans are isolated and undervolted, then absolutely there is a difference. (And this is SPCR, so I'd expect many people to already have done something to keep the noise level down)

p.s. you do need to use a lot of sound absorbing material. Thin material is useless - for example, the thin Lian-Li sound proofing I saw on some cases before, I consider as just a gimmick. I have over 10mm of multi-layer sound absorbing material in some places close to active noise sources.

JamieG · Post by **JamieG** » Tue Aug 11, 2009 4:28 pm

echn111 wrote:Accoustic absorbant material / dampening does help to reduce PC noise. BTW: I'm not particularily aware of the differences between the two terms and use them interchangably. And all my dampening material is expected to be reasonably accoustic absorbant material anyway; it's not like I'm going to use aluminum or tin to dampen my case.

IMO there is a bit of a difference if by damping you are referring to mass damping:

- Mass damping is adding weight to something to stop it vibrating so easily.
- Acoustic foam (i.e. acoustic damping) is designed to reduce the perception of sound by absorbing certain frequencies.

Acoustic foam is often quite heavy, so it serves as a bit of mass damping as well. However, some materials used for mass damping, such as self-adhesive vinyl floor tiles or bitumen-based products (similar to roofers tape etc) are not as good as reducing airborne noise but adds mass to thin case panels etc to stop case vibration noise.

My $0.02 anyway.