Vibration spectrum!

[epilot]

Hello,

Just want to know if there is any way to see the ACTUAL air vibrations produced by a speaker. something like using of smoke or..
but I need a perfect, cheap and practical method

 

[Sceadwian]

Exactly what do you need to see? If you're trying to measure the cone deflection you can attach a small needle to it and put a white card behind it to see how the speaker is vibrating. There has to be some reason for you wanting to see this, exactly what are you trying to determine? The more information you can provide the better an answer you'll get.

 

[epilot]

Exactly what do you need to see? If you're trying to measure the cone deflection you can attach a small needle to it and put a white card behind it to see how the speaker is vibrating. There has to be some reason for you wanting to see this, exactly what are you trying to determine? The more information you can provide the better an answer you'll get.

Sorry,

Well I want to see the vibration of the air particles somehow.
for example to look at how directional the speaker, tweeter or my sound source is really.

 

[Sceadwian]

There is no simple cheap or practical method of doing that. But the directional dynamics of a cone type speaker are very well documented. The following two links will provide you with all the information you need about vibration.

**broken link removed**
**broken link removed**

Some really good information in there.

 

[The Mad Professor]

Well there is the Rubens tube experiment, though it's not quite what you are looking for.
https://www.youtube.com/watch?v=W9_mIS0xmyg

Perhaps "canned smoke" or maybe a fluid medium inside an old fish tank illuminated with a strobe light might do the trick.

 

[stevez]

Air that is saturated with moisture might reveal a bit but any setup for this would be far from cheap or easy.

 

[evandude]

It's not nearly as "wow, cool" as actually seeing the sound waves as you want, but if you're really just interested in finding the directionality of some speakers, just use a microphone and move it around in front of the speaker at whatever distance you want, and compare the relative sound amplitudes as you get further from perpendicular with the speaker.

 

[justDIY]

this one is particularly striking

https://www.youtube.com/watch?v=K9AvhVWXMr8&NR

 

[audioguru]

Cool patterns. The white sand on the beach looks like that when I scream.

Their "sound board" makes a lousy piston because at some frequencies only parts of it are moving. The parts that are motionless have destructive cancellation.