nevermind, stuff sounds kind of nasty now.

Agree, it's quite decent.
It adds enough mass to dampen vibrations and also has enough "soft stuff" for more than aesthetics... unlike overhyped Akasa Paxmate what some shops sell as only quieting product.
And it's even among the most affordable ready dampening products for PCs in Europe.


Any material will do that if you block enough airflow... or even little airflow in wrong place.

Anyone that claims damping material raises case temperatures is either talking bullkaka or not doing it right. You might see a few degrees difference, but i've never seen that. And you could also argue that the reduced volume inside the case accelerates airflow, resulting in better cooling.

You could argue that, but generally you'd be wrong. Your case is not an air-tunnel. Cooling is mostly accomplished by circulating the air within the case. If it just went in and out things could only be cooled:
1) if they were directly in the path of the airflow (this was the idea behind BTX, but the execution proved to be so-so)
2) airflow was so great you created a vacuum effect that actually improved circulation in the rest of the case -- unfortunately this would make a noise like a vacuum cleaner!

I think most would argue that increasing volume is better for silent cooling as it takes longer for a large volume that is being circulated to heat up than a smaller volume. Anyway, you are correct that damping material as generally applied is going to effect the air volume of the case much one way or another and that is also why it tends to be very limited in quieting cases through anything other than mass loading. To get rid of the non-vibration sounds, you either need a great thickness of material or you need to start blocking the holes through which air is entering/exiting. Blocking those holes may very well effect your cooling situation (but not always, as they can sometimes be extraneous to airflow requirements).

But it's also true the other way round !!!! It takes longer to cool a large volume of warm air. So I don't quite agree with that part of what you're saying.

As long as you don't have "pockets" of air in your case, and as long as your fans allow for some cool air to get in and for some hot air to be exhausted, there is no reason that a damping material would heat up your case if you don't change your airflow pattern.

I use the acoustipack stuff. Works great when applied around an HD cage and around a PSU. Keeps the noise down and muffled.

No, you are confused. The purpose of the fans is not to cool the air. They are there primarily to help the air circulate through the case. Their secondary purpose is to exhaust the old/bring new air into the case. The reason that is the secondary function is that this would happen anyway, unless your case was airtight. If you reverse priorities, as you suggest, either every component needs to be in the airflow path (not possible in an ATX setup) or you need so much pressure that it will be very noisy.

Exactly right. However, this means that the only thing you will be able to achieve with your damping material is mass loading. There is no way to do anything about most airborn noise without using a very thick layer of material or blocking some holes -- either of which will effect your airflow.
Again, the argument is not that damping materials do nothing, just that they do a lot less than many people are expecting. I just want people to makes sure they have done things like work on silencing their fans and HDD, before getting too excited about damping.

I definately agree with you that damping material does not make a huge difference in sound volume in most cases, but it does make the sound smoother and even thinner layers work pretyt well on high frequency noise like HDDs..

But if you have a big case it's easy enough to have thick layers or foam and do some pretty effective damping of the intake without too much added restriction.

@ jessekopelman : I didn't phrase what I had to say quite the right way but I understand your point and I totally agree with what you're saying. I just wanted to say that no matter the volume, you need to keep the air inside the case not too warm. And if it takes longer for the air in a large volume to heat up, it also take longer for that same volume to cool down.

Back on topic
Has anyone tried making a duct out of sound absorbing material (didn't find one in the galery) ? Or even better, a duct OUTSIDE the case to direct exhaust airflow. Because that would seem to be the best solution. Like an "L" shaped duct maybe...
If someone has tried, what material did you used ? you'd need something easy to cut and glue together...