On Wednesday, October 24, 2012 9:44:52 PM UTC+1, Andy Dingley wrote:
No - because Fresnel doesn't work in "small". For optics, a convenient size is (optically) "large", so they work. For acoustics, a sensibly sized gadget is going to be (acoustically) small, relative to wavelength. So your gadget is going to suffer from so much diffraction as to stop it working.


but it will work at high frequencies and that's just where you need to increase the signal. wavelength is 8cm at 4kHz

Robert