Painting egg carton with ceiling texture sprayfoam?

[yofiel]

Hi folks

I don't know if anyone asked before, I'm pretty new here...I'm working on a sound baffle for a computer. I have some spray 'popcorn' left over from painting a ceiling. I thought maybe spraying a few sheets of cardboard for 96 eggs with it (they sell eggs in big packs like that here some places). The egg carton shape seems good, and the ceiling popcorn is designed for noise deflection, and I can boil the eggs, give a bunch to the local food bank.

Then if that works, I can fill back of the egg carton with plaster of paris for solidity, and even back that with a sheet of plywood and painting it for the external of the enclosure, if it goes on the road.

Does that sound a good idea?

[yofiel]

oh...lI guess I should add, I tried acoustic fooam, but for a computer enclosure it didn't work very well, in particular, hot air from the fans would saturate the foam, and the foam became brittle and crumbly.

Ceiling popcorn is meant to be fire resistant, and it would protect the egg cartons. Also, the foodbank likes getting eggs. Most their food is from supermarkets when it is past sell-by date but within buffer time allowed for home refrigerators (3-6 weeks depending on foddstuff), but supermarkets aren't allowed to give food banks dairy products past sell-by date. So they very rarely get eggs

I'm just not sure how well it would work as a sound baffle, and I was wondering if others had tried celing popcorn and egg cartons, or had better ideas?

[sheggs]

Reality is this - although covering your walls and ceilings with these products will change the sound of your room - they really don't amount to much. They have no density to speak of - and thus do not affect low frequencies, as a diffusor they are much too shallow and too uniform to have any real effect. In short, even if you can get them for free - they aren't really giving you anything (acoustically) of value in your room.

For actual test data - please visit this site: http://www.acousticsfirst.com/eggc.htm
That should settle the question.

[yofiel]

Hi, thanks but this is not for room. It is for computer cabinet enclosure not room. A bare box accentuates hiss and woof, fan noise echoes inside, and it gets hot. woiuld ceiling popcorn on a flat surdace would be just as good?

[Mixedup]

The egg carton shape seems good, and the ceiling popcorn is designed for noise deflection

For a 'baffle' - ie a gobo - just use a dense mineral wool panel. It's affordable and it's fire retardant. Coat it in a breathable fabric (weed matting, cotton sheet etc) and you have what you need without all this fannying about.

For an 'enclosure' the shape isn't going to make a shred of difference, in that it doesn't matter if sound is bouncing around as long as it doesn't get out. So egg box shape doesn't seem to me like it would add anything useful there.

If you're keen on breaking up HFs from the computer for other reasons, build a diffusor out of wood, or use books, CDs etc that you have lying around. But I can't think why you'd want to do that.

Finally... dare I suggest just working on fans, fan speeds for the PSU and cooling, and on drives (SSDs?) t get a quieter machine in the first place?

[yofiel]

Thanks, that's a good idea. I went through all the fan business with Zalman etc for the last five machines. This one I have space for a better solution, rather than mucking with yet more fans, and I want something that can go on stage too.

There's real things to reduce the fan noise -- using ball bearing fans instead of sleeve fans etc -- and there's increasing size of heatsink, but beyond that and liquid cooling, most solutions realy reduce noise by reducing air flow. I haven't got into liquid cooling yet.

[yofiel]

oh, there was one other thing I found actually made the most difference: rubber grommets.

Also I put it on thick sponges to reduce vibration passed to the floor. The sponges need replacing twice a year.

[Mixedup]

You can also go for fewer fans and fewer moving parts. Eg larger fans but running slower to draw air in through the front and vent at the back. Fanless graphics card(s). Solid State Drives. Neat cabling so you can manage airflow to make cooling more efficient etc etc.

Bear in mind that the more enclosed your system is, the poorer the air circulation and thus the more you're going to need to cool it. Which might mean creating more noise to attenuate. Bit of a vicious circle! Best option if noise is a real issue (no reason a PC needs to be excessively loud now, though) is to move the actual machine away from where it interferes sonically and to have your keyboard, mouse, VDU etc where you need it. Like a machine room in an old studio, or a server room in an office...

Also, water cooling = not as good an idea as it at first seems. Not that it doesn't work, but you're replacing an internal fan with an external pump... which won't be silent.

[Martin Walker]

oh, there was one other thing I found actually made the most difference: rubber grommets.

Also I put it on thick sponges to reduce vibration passed to the floor. The sponges need replacing twice a year.

Hi yofiel!

When you say "it" followed by "sponges need replacing twice a year" I can only assume that you mean resting the entire PC on the sponges.

If instead you hang your hard drives inside your PC from rubber cords you'll make a much bigger difference to the level of drive vibration transmitted into the rest of the case

Here's a photo of a typical DIY assembly:



I also echo Mixedup's advice of larger fans (e.g. 140mm) running more slowly as a great way to reduce acoustic noise levels.

Martin

[yofiel]

That's good advice too, thank you. For the next installation, I'm thinking now about two rack-mount i7 Windows8 Professional boxes, with wireless audio connections, in a ply enclosure with inside coated with under-carpet acoustic insulation fiber matting.

The rest I can put together, but I'm not sure about the wireless audio connection. Fry's showed me a USB device the size of a garbonzo bean for connecting a digital amp to a wireless network. What I need is to send multiple audio channels on 802.11 then. That is new to me, is there a simple way to do this these days?

[yofiel]

Looking around, it appears there is not. There are some geeky ways to do it, and some boxes for ADAT over Ethernet costing a thousand dollars, but not any straigntforward, simple digital audio connection over a dedicated TCP/IP crossover link. What a surprise...

[yofiel]

oh...doesn't need a hard disk....
solves alot of problems

http://www.redmondpie.com/how-to-make-windows-8-bootable-usb-flash-drive-the-easy-way/