Messung der Amplituden- und Phasenverteilung auf Konuslautsprecher-Membranen

A continuous recording of amplitude and phase over the whole conical diaphragm of a loud-speaker is made. Whereas the motion at low frequencies is of piston form, at moderate frequencies azimuthal variations and at higher frequencies radial variations become apparent. With warble tones or noise bands a ring zone of maximum amplitude appears on the membrane, which moves towards the centre as the frequency goes up. The piston type vibration is more important for radiation at low and middle frequencies, the azimuthal flexural waves superposed thereon having little effect.