Amplitude and Frequency Modulation Distortions of a Loudspeaker
The measurement techniques and the causes of amplitude and frequency modulation distortions are discussed using a two-way coaxial-type loudspeaker system. The distortion due to amplitude modulation is caused by the dependence of the radiation efficiency of the high-frequency driver on the displacement of the diaphragm of the low-frequency driver. The distortion due to frequency modulation seems to be produced when the high-frequency sound has a nonzero particle velocity in the axis direction at the surface of the low-frequency driver diaphragm. The symmetry of the sidebands of the summed modulation distortion (intermodulation distortion) indicates that the amplitude and frequency modulation distortions are 90° out of phase with each other.
Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $33 for non-members and is temporarily free for AES members.