Go for it. One thing to consider is that satellites were designed with the purpose of operating in a vacuum and your mics were not.
Yeah my primary concern lies over the uncertainty of using things outside of its intended use. Since it looks like nobody has attempted this before, then there's only 1 way to find out!
Brb, I gotta get myself one of those 'Space bags'
In the mean time, here's an overview of the experiment:
Rationale:
Somebody asked me how to differentiate between the self noise of the microphone's build from the noise caused by the random movement of air molecules surrounding the diaphragm. He wanted to be able to HEAR the microphone's "true" self noise. This is useful information for recordists who are operating very close to the noise floor trying to record quiet distant sounds/signals - whether the poor signal to noise ratio is attributed to the limitations of their microphone (time to upgrade) or to the limitations of the environment (no need to upgrade).
Yes, the noise floor is made up of multiple noise sources throughout the signal flow: preamp noise + electrical noise from power sources + electromagnetically induced noise (radio waves) in wires and antennas + microphone self noise + ambient noise. There are several ways to uniquely identify these variables so that you could eliminate them from the equation to eventually isolate the microphone's self noise, but there's the dead end. I haven't come across any method that tries to differentiate the electrical self noise caused by the build of the microphone from ambient noise caused by the atmosphere.
I cannot compare 2 different mics vs a constant atmosphere, because we need measure the atmosphere by how it sounds like, which has no absolute value and is not recorded as a constant variable because each microphone hears it differently due to their unique sensitivity, frequency response, and polar patterns - unnecessary variables to deal with.
It makes more sense to keep the microphone constant and vary the atmospheres. Better still, ELIMINATE the atmosphere.
Manufacturers use anechoic chambers to test and calibrate microphones, but it's not enough for this experiment because a microphone in these chambers can probably still hear an ambient noise caused by random motion of air molecules. People who sit in an anechoic chamber will start to hear their own blood flow and heartbeat as well as a kind of white noise-like hiss that rings in the ears and gets louder until it's deafening. Some claim that this hiss is completely neurological, others claim that it is the air bouncing off the eardrums. For the sake of this experiment I'll assume the latter is true.
With the vacuum bag setup, indeed there will still be some air remaining and we can never achieve total vacuum. But if the reduction of air is enough to cause a significant difference in what the microphone hears vs. in normal atmospheric conditions, then we're still on to something
The walls of the bag will come into contact with the microphone casing (The mesh that encapsulates the diaphragm) but not with the diaphragm itself. The space between the casing and the diaphragm serves as the "vacuum".
Hey, missed this. Mostly all you need is a fairly stable temp and humidity and to keep dust out. A loose fitting plastic bag is a recommended way to go!
Generally moisture is only a problem with rapid temp changes.
Interesting, never thought of it that way. Thanks!
findings on such experiments need to be documented.
why helpful? 
