Completely nuts idea for air cooling!

[D4S4]

Ok, the tools needed for this experiment:

1. water-cooling setup with radiator on the outside
2. subwoofer (the bigger, the better), actually anything that moves a lot of air through the bass-reflex port
3. some good house or hip hop music, anything with lot of bass will do (Run it by Chris Brown should do nicely), or some audio production program (FruityLoops)
4. ear plugs (optional)

Assemby:
1. put your radiator couple of inches away from bass-reflex port (vertically) like this
r
a
d
i <--Bass-reflex
a <--port
t
o
r
2. music to the max!!!
3. observe your temps
This should be working on principles similar to synthetic air jet cooling, if there's anyone nuts enough to try this, keep me posted

[btarunr]

oh and when the music is off,

heating to the max!!!

Why would anyone run benches with music running? The audio app and the audio hardware cause CPU overhead anyway.

[Wile E]

Originally Posted by btarunr

oh and when the music is off,

heating to the max!!!

Why would anyone run benches with music running? The audio app and the audio hardware cause CPU overhead anyway.

Not if you run it from your CD player and receiver.

[btarunr]

Alright, so it's loud-blasting music to cool, then. How about just a high speed fan or something. You can make air-jets using compressor mechanisms as well.

[D4S4]

Run the music off an mp3 player, stereo, anything else??? Crap, need to go to school... I'll be back!

[Wile E]

Originally Posted by btarunr

Alright, so it's loud-blasting music to cool, then. How about just a high speed fan or something. You can make air-jets using compressor mechanisms as well.

That's what I would do. If I wanted truly crazy airflow thru a rad, I would use a compressor setup of some sort.

[D4S4]

Originally Posted by btarunr

Alright, so it's loud-blasting music to cool, then. How about just a high speed fan or something. You can make air-jets using compressor mechanisms as well.

Read the Synthetic air jet article. These jets are much more coherent and pulsed, if you put your hand meter, meter and half form a fan, you'll barely feel it. On the other hand, put your hand meter away form a bass-reflex port and you'll fell the blasts. My Logitech x-230 sub demonstrates this quite nicely. These jets are shaped like smoke circles some people make while they smoke, that's why they travel that far and they take off the thin surface layer of air much better than continuous jets (e.g. fan). Now i really should run, I'll be back in some 7-8 hours.

[Wile E]

Originally Posted by D4S4

Read the Synthetic air jet article. These jets are much more coherent and pulsed, if you put your hand meter, meter and half form a fan, you'll barely feel it. On the other hand, put your hand meter away form a bass-reflex port and you'll fell the blasts. My Logitech x-230 sub demonstrates this quite nicely. These jets are shaped like smoke circles some people make while they smoke, that's why they travel that far and they take off the thin surface layer of air much better than continuous jets (e.g. fan). Now i really should run, I'll be back in some 7-8 hours.

That just demonstrates high pressure and speed. It doesn't account for the volume of air being moved. The amount of air being moved as a function of time can be every bit as important as the speed and pressure of that air, when it comes to cooling a radiator.

[Bundy]

Using a typical subwoofer sound frequency of say 50Hz and speed of sound 340m/s, wavelength can be calculated to be 50/340 = 0.14m. Waves will not generally pass though a hole smaller than half the wavelength (which is why we see subwoofers with big holes in them) so the radiator would need it's fins to be spaced more than 0.07m to allow sound wave transmission. If they are closer, the waves will reflect.

I would expect the subwoofer would rattle the living hell out of the radiator and itself and move almost no air through the radiator. If the subwoofer is big enough, it might even go bang. But I'd love ya to give it a try

[klva80]

Originally Posted by bundyrum&coke

Using a typical subwoofer sound frequency of say 50Hz and speed of sound 340m/s, wavelength can be calculated to be 50/340 = 0.14m. Waves will not generally pass though a hole smaller than half the wavelength (which is why we see subwoofers with big holes in them) so the radiator would need it's fins to be spaced more than 0.07m to allow sound wave transmission. If they are closer, the waves will reflect.

I would expect the subwoofer would rattle the living hell out of the radiator and itself and move almost no air through the radiator. If the subwoofer is big enough, it might even go bang. But I'd love ya to give it a try

we don't see big hole in subwoofers, what we see are what we like to call tuning ports, those ports have a measure and a depth to rise the db's of a specific frequency, a 38 hertz bass port should provide sufficient airflow and pressure, it to can bust your eardrums at high volumes or continuous listening even with earplugs, allow me a video so you can sea what i mean.

but hey it could just work


Pimp My Ride

[Network_guy]

not gonna work, for subwoofers like mine, being a logitech z5500 it needs to be 60cm away from all electronic equipment because of its magnet

[Easy Rhino]

you're right. that is completely nuts.

[King Wookie]

The problem is you don't feel the air being drawn in by the "reverse" stroke of the sub driver.
Remember, the diaphragm is moving in both directions.

The whole idea of a speaker is to create vibrations, not air movement. Any air movement through the port is a bye product of inefficiency.

I like the pulse jet idea, but think a better mechanism is needed.

Then again, wouldn't constant air movement be more efficient at heat transfer?
(thermodynamics is not my strong suite)

I do applaud your radical thinking though.

[Steevo]

Originally Posted by bundyrum&coke

Using a typical subwoofer sound frequency of say 50Hz and speed of sound 340m/s, wavelength can be calculated to be 50/340 = 0.14m. Waves will not generally pass though a hole smaller than half the wavelength (which is why we see subwoofers with big holes in them) so the radiator would need it's fins to be spaced more than 0.07m to allow sound wave transmission. If they are closer, the waves will reflect.

I would expect the subwoofer would rattle the living hell out of the radiator and itself and move almost no air through the radiator. If the subwoofer is big enough, it might even go bang. But I'd love ya to give it a try

Passively perhaps not, but a sub is a active source. The density of air increases and the speed of sound changes with that increase of density making the tuning ports on subs act more as a relief for certain frequencies and reinforcing the wave eminating from the driver itself for other frequencies.

[Steevo]

Originally Posted by King Wookie

The problem is you don't feel the air being drawn in by the "reverse" stroke of the sub driver.
Remember, the diaphragm is moving in both directions.

The whole idea of a speaker is to create vibrations, not air movement. Any air movement through the port is a bye product of inefficiency.

I like the pulse jet idea, but think a better mechanism is needed.

Then again, wouldn't constant air movement be more efficient at heat transfer?
(thermodynamics is not my strong suite)

I do applaud your radical thinking though.

That idea would mean that a sub in a vacum box would work great, but it doesn't. The sound travels as waves of compression in the air the sub is moving. Air waves or sound waves, out of phase will cancel each other out, and in phase will reinforce. A ported sub will have certain frequencies that it can produce better than a enclosed, and some worse due to this fact.

[King Wookie]

Originally Posted by Steevo

That idea would mean that a sub in a vacum box would work great, but it doesn't. The sound travels as waves of compression in the air the sub is moving. Air waves or sound waves, out of phase will cancel each other out, and in phase will reinforce. A ported sub will have certain frequencies that it can produce better than a enclosed, and some worse due to this fact.

Of course it won't work in a vacuum, as there is no medium to cause to "vibrate".
The point I'm trying to get across, is that the air movement is a bye product. If the compression modes were reliant on air movement, then wind=sound.

Considering I'm lecturing in sound theory, I need to work on explaining myself better.

I do agree with you, but I'm evidently not being clear here.

[Steevo]

Wind is not a wave and thus not a sound as we percieve as it is either such a low frequency or has no vacum exibited on the trailing edge of the pressure wave. Either way air movement is not a total waste of sound energy.



Think of this.


A speaker retracts causing pressure to drop in front of the driver cone air moves in to equalize and a low pressure zone radiates out from the front of the driver. In the box the pressure rises and seeks a way out, traveling through a tube that causes the speed of the air to increase creating the wind you feel and also a delay. By the time the air reaches the end of the tube the driver is moving forward creating a positive pressure at the same time the air escaping from the tube has slightly increased the density of the air around the enclosure reinforcing the positive pressure wave thus increasing sound volume. This only works on small ranges of frequencies however, and the tube is designed to mitigate the difference in frequencies that are out of phase. This is how a Bose waveguide produces sound in the manner it does, alot of engineering and work to make the most of what you have.

I am guessing english is not your first language.

And I have none other yet, being a product of the enviroment of US schooling.

[klva80]

well we can try with my car audio system, but the only question is how safe would it be the computer in my trunk

[imperialreign]

I actually thought of doing something similar a while back, using a reflex-style subwoofer housing. In theory, if you could connect a tube from say, the back of the case to the reflex tube on a subwoofer, and add louvers to the tube so air could escape en-route to the sub woofer, the pull from the cone would act as a vacuum to the case . . .

couple of issues, though - unless you're running at minimum 15" subwoofer, you wouldn't have enough pull for it to be effective. The louder you crank it, the faster the cone is traveling and wouldn't really do anything for air flow at all really. You'd get better airflow with a med-speed 120mm fan.

My other thought, though, to position a subwoofer close enough to couple to the case and actually be effective - I couldn't imagine the kind of EMI that could potentially be introduced to various components of your system - let alone, if you're running a massive CPU cooler, or some extended length video cards . . . that's a TON of vibration, much more than the components were originally designed to handle.

[D4S4]

My internet connection has been out for couple of days... wireless trouble, don't ask, messy business

Anyways, all i have to say is less theory, more practice. 38Hz is most air-moving frequency for my subwoofer, i already made a 10 second loop for my mp3 player. I'm trying this as soon as i get my hands on a camera and there's nobody home (sounds like i have an airplane in my room). I could try with my phone camera, but pics would be very crappy. Expect results in a couple of days.

P.S. it's not the sound that matters, it's the airflow from the port. Already tried putting the sub blasting into case, saw 6-7 degree drop on my video card in far from optimal conditions.

[Bundy]

Did it work?

[a111087]

not very practical way, but I already heard about sound waves to help in cooling

[imperialreign]

I had even considered it as well, but didn't feel it was worth the effort . . .

I'm interested to see what results someone else might have had, though

[magibeg]

Originally Posted by Network_guy

not gonna work, for subwoofers like mine, being a logitech z5500 it needs to be 60cm away from all electronic equipment because of its magnet

Why is no one listening to this guy? Theres powerful magnets in subs (well subs that would give off a powerful pulse of air anyway) that could definitely screw up something electronic. Unlike most other speakers the subs are usually not shielded.

[Bundy]

Originally Posted by magibeg

Why is no one listening to this guy? Theres powerful magnets in subs (well subs that would give off a powerful pulse of air anyway) that could definitely screw up something electronic. Unlike most other speakers the subs are usually not shielded.

LOL - thats why I followed up on this, to hear whether carnage was wrought.