Loudspeakers Maximum Volume before the Air Distrorts

[WooferHound]

A long time ago I heard that when sound is produced at high volume levels the air is capable of being distorted. The speaker produces pressure waves and vacuum waves as the Cone oscillates forward and backwards. At some point the Vacuum waves become a total vacuum and the sound in the air is distorted as a result. Eventually as you get away from the speakers the volume reduces enough for the air to repair itself.

The problem would be microphone placement, like in front of a guitar amplifier, where you don't want to place the mic in an area that has this total vacuum wave air displacement.

I had heard that the volume that this happens at is about 120 db. Recently I have talked to a sound tech for a major production and he was trying to explain to me that this problem only occurs at a much higher volume of 160 db which may be possible directly in front of a guitar amplifier speaker.

Do any of you guys know what Decibel level this occurs at and how to place a microphone to avoid this high volume air distortion area?

 

[DuckJordan]

I don't believe anything remotely close to what a microphone can handle could possibly "break" the air, Considering what is being fundamentally talked about here is whats the Decibel at which sound reaches the power to reform air waves in such a way to disrupt them. I keep thinking it would have to be close to the energy it takes to break the sound barrier.

 

[gpforet]

There is no speaker I'm aware of that will create 160db. The pressure would collapse even the strongest cone or driver.
I work in the aerospace industry which has a sonic fatigue lab, and pressures above 140db are created using air driven by compressors and routed thru modulation valves. These valves are driven by high current amplifiers (believe it or not, crown dc300 modified for driving additional current sources).