Posted by Wayne Parham [ 66.137.59.19 ] on April 01, 2004 at 06:16:09:

In Reply to: Re: Can't reproduce a square wave (some can) posted by Tom Danley on March 17, 2004 at 16:09:51:

Hey, Tom - What do you make of this? Do you have any references for research data that shows the onset of air compression non-linearity?

I assumed it must be somewhere between 1.5 and 2 atmospheres for a sinusoidal piston motion that creates alternating compression and rarefaction. I also would guess that plenums, vents and other resonant chambers would have certain frequencies where they were more sensitive due to resonant conditions. At frequencies where a vent or plenum is resonanting, we'll get a ram-charge effect where critical pressures are reached at lower piston excursions.

But putting resonance aside, I wonder where air rarefaction/compression starts becoming noticably asymmetrical, causing non-linear distortion. Kinda thought you might know a reference or two.

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