Aluminum Cases and Dynamat

Enclosures and acoustic damping to help quiet them.

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Francis
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Aluminum Cases and Dynamat

Post by Francis » Sat Jan 04, 2003 5:07 pm

Hi! I'm new to the topic of quieting PC's.

I've been thinking about getting an aluminum case for the extra cooling. Does aluminum really make a substantial difference or is this somewhat hyped?

I'd like to know if adding a sound absorption material inside such as Dynamat Extreme would negate any benefits of using an aluminum case. I'm guessing that some heat would still be conducted through metal parts such as drive bays, even though much of the interior area would be covered with Dynamat and be insulated.

Also, does aluminum make an intrisically noiser case (in regards to the type of vibrational noise Dynamat is supposed to reduce)? Since aluminum is a lighter material, ittransmits vibration more easily? (It's used in musical instruments like vibraphones & glockenspiels, isn't it?). Just wondering!

MikeC
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Post by MikeC » Sat Jan 04, 2003 5:54 pm

Aluminum cases don't really provide better cooling. It's only if aluminum is used as a heat transfer device -- like a HS -- that its higher heat coefficient comes into play. In the typical case, the only place this MAYBE has an effect is when the drive is mounted conventionally (secured tightly with screws). Do you think the difference vs steel would be more than a couple of degrees? (no) or that a change in position of the HDD to a higher/lower airflow spot would make a far bigger difference? (yes)

Your suspicion is dead on: aluminum cases are hyped -- mostly not by the case makers or sellers but by the buyers, as far as I can tell. Case makers/sellers just choose not to enlighten. Why should they if it doesn't hurt anyone and helps generate more sales for more profitable goods?

Dynamat Extreme and similar products are NOT sound absorption materials. They are panel dampeners. They reduce panel vibrations. You can see why these sorts of products would be useful for improved audio in a car with its large areas (relatively) of unsupported sheet metal panels. See Ken's review of the similar Brown Bread.

Sound absorption occurs with soft materials such a spongy acoustic foam, fiberglass, wool, etc. Materials such as these are designed specially to absorb sound - mostly -
http://www.muffledcomputing.com/foam.html
http://www.akasa.co.uk/pasmate/paxmate.htm
http://www.acoustiproducts.com/en/products.asp

They do block sound somewhat and damp panels as well, depending on density, adhesion, etc but those are generally more secondary functions.

I am working on a comparative review of the these products right now; look for that in a week or two. :wink:

IMO, aluminum actually does make a noisier case -- in theory. This is especially true with the very thin-paneled cases being produced. The heavier steel panel cases do have intrinsically better damped qualities -- that is, they benefit less from dampeners such as Dynamat or Brown Bread. But if you can reduce the noises at their source, the type of case makes very little difference.

>> Added: Differences in the material are, in practical terms, so much less significant than those in design and execution. In other words, regardless of whether it's steel or aluminum, I think the better design will cool and quiet better.
Last edited by MikeC on Sun Jan 05, 2003 2:20 am, edited 1 time in total.

GamingGod
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Post by GamingGod » Sat Jan 04, 2003 10:44 pm

hmmm i just got an idea, u know that rhinocoating stuff that u paint onto the back of trucks to seal them? its kinda rubbery black tar stuff, i wonder if that stuff could be used in a computer case to quiet it down?

Stephen7372
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Post by Stephen7372 » Sun Jan 05, 2003 12:49 am

If your doing a review please can you include http://www.power-snooze.com/

I've always wondered if it was any good :wink:

Gandalf
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Post by Gandalf » Sun Jan 05, 2003 2:14 am

I recently replaced my Aopen HQ08 case with a Lian Li (PC61) aluminium case. This case is a lot smaller, but despite its size it *does* cool better. The airflow is a lot better and it's at least as silent, of not silenter!
Really, I'm quite baffled by this, because my Aopen Case has 1 and 2mm steel whereas this case has 1mm (and less!) aluminium.

auxyone
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Post by auxyone » Sun Jan 05, 2003 11:32 am

I have a Cooler Master ATC-111 aluminum case. I bought the (too expensive) case mostly because of its looks, space, and great (airflow) cooling. My case temp is a consistent 22c. That said, I did buy the case knowing that I couldn't benefit from the aluminum in any other realistic manner.

While I like the ATC-111 a great deal, it took me a long time to successfuly combat the noise amplified by just the case. To do this, I used Akasa PAX and rubber fan isolators. Together, with a Zalman heatpipe, Smart Drive, and "silent" CPU cooler, the case is very, very quiet. But I did have "work" at it a bit more than average to make the case as quiet as it is.
Last edited by auxyone on Sun Jan 05, 2003 1:02 pm, edited 1 time in total.

schnee
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Post by schnee » Sun Jan 05, 2003 11:35 am

auxyone, you and I have almost the *exact* same setup.

Weird. Very, very weird. :D

Gandalf
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Post by Gandalf » Sun Jan 05, 2003 11:54 am

I found the coolermaster cases to be not too loud ..

tm
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Post by tm » Sun Jan 05, 2003 12:48 pm

MikeC wrote:Aluminum cases don't really provide better cooling. It's only if aluminum is used as a heat transfer device -- like a HS -- that its higher heat coefficient comes into play. In the typical case, the only place this MAYBE has an effect is when the drive is mounted conventionally (secured tightly with screws). Do you think the difference vs steel would be more than a couple of degrees? (no) or that a change in position of the HDD to a higher/lower airflow spot would make a far bigger difference? (yes)
When I asked a question about aluminum cases, someone brought up a comparative review done by Anandtech, and their results indicate that there's, at most, a few degrees difference in case temperature, probably within measurement error. The biggest difference was in the HDDs which were presumably hard mounted.
MikeC wrote:IMO, aluminum actually does make a noisier case -- in theory. This is especially true with the very thin-paneled cases being produced. The heavier steel panel cases do have intrinsically better damped qualities -- that is, they benefit less from dampeners such as Dynamat or Brown Bread. But if you can reduce the noises at their source, the type of case makes very little difference.
Good (that is, costly) aluminum alloys are also intrinsically a lot stiffer than steel alloys. Consider bike frames: Steel still has a place in that industry, despite its relative weight disadvantage compared to aluminum, since steel gives a different, "softer" ride than a stiff aluminum alloy bike. And steel is generally cheaper, of course. At the same thickness, steel should, in theory have better dampening characteristics at most frequencies since it should be able to absorb and dissipate more sound than aluminum. It should not have anything to do with the weight of the panel, if we're dealing with sound transmission characteristics and not much larger (and thus far noisier) mechanical vibrations. Consider titanium vs steel, they're about the same in terms of stiffness, but titanium is far lighter. I say all this with the caveat that I'm not a materials science expert at all, just using my fancy degree in physics to do some stabs in the dark :)

I think the main practical differences between aluminum and steel are the weight and cost. Given the lengths we go to in eliminating the sources of noise inside, it would seem that the differences in materials would not matter much.

I totally agree with the point that design and construction of a case are far more important than the material.

Francis
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Post by Francis » Sun Jan 05, 2003 2:34 pm

MikeC wrote:I am working on a comparative review of the these products right now; look for that in a week or two.
Mike - thanks for the overview and the links - this should give me a place to start looking. I'm really looking foward to seeing an article on this. More reviews of cases (and maybe the Acousticase) would be great to see as well.

I was curious about the Acousticase. Does anyone here have one? It's expensive, but not a lot more expensive than some of the aluminum cases I looked at. Looking at the assembly diagram though, it was hard for me to figure out where the "drive bay" was (apart from the 5.25 bay slots). I was wondering if it might have a drive bay situated in front of the front fan - I wouldn't be able to use this case if I couldn't have proper drive cooling for a 10K drive. Would this case be usable for 10K SCSI drives?

About Dynamat Extreme & Brown Bread panel dampening products - although Dynamat's is more expensive, I'd buy it over something that is tarlike. The Brown Bread review made it sound, though, that the final result was not overwhelming - anyone care to share their experiences?

Also, if I got a new case with 2 8cm fans in front, what kind of bezel / fan guard is preferable? I saw some that had a fine screen (like a speaker on a boom box) instead of holes in the case - is this type better for reduced noise, or is it too hard to generalize?

Thanks to all who've replied so far!

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