Abstract: A method for audio distortion processing is provided, whereby narrowband and wideband gains are incrementally reduced and recovered for controlling audio distortion of an audio reproduction system. Reduction limits are determined for both the narrowband and wideband gains, as a function of operator controlled inputs. If clipping is detected, the narrowband gain is initially reduced until either the narrowband gain reduction limit has been achieved or the clipping desists. The wideband gain is subsequently reduced if the reduction limit of the narrowband gain has been achieved and the clipping persists. The wideband gain is reduced until either the wideband gain reduction limit has been achieved or the clipping desists. After the clipping desists, a gain recovery process ensues, whereby the wideband gain is initially recovered until at its original level and the narrowband gain is subsequently recovered until reaching its original level.

Abstract: A method for audio distortion processing is provided, whereby narrowband and wideband gains are incrementally reduced and recovered for controlling audio distortion of an audio reproduction system. Reduction limits are determined for both the narrowband and wideband gains, as a function of operator controlled inputs. If clipping is detected, the narrowband gain is initially reduced until either the narrowband gain reduction limit has been achieved or the clipping desists. The wideband gain is subsequently reduced if the reduction limit of the narrowband gain has been achieved and the clipping persists. The wideband gain is reduced until either the wideband gain reduction limit has been achieved or the clipping desists. After the clipping desists, a gain recovery process ensues, whereby the wideband gain is initially recovered until at its original level and the narrowband gain is subsequently recovered until reaching its original level.

Abstract: Automobiles having convertible tops and audio systems are provided with a first audio equalization mode for closed car conditions and a second audio equalization mode for open car conditions. The appropriate audio equalization mode is selected automatically upon raising or lowering the convertible top. In order to minimize inadvertent switching of modes, a timer is included in the system to delay switching from one mode to the other. The timer times a period of about three seconds.

Abstract: A pre-recorded test tape or test disk which is used to isolate unwanted buzzes in an audio listening environment. The prerecording is a series of varying amplitude frequency sweeps. The frequency sweeps from the audible range of 20 Hz. to 400 Hz., while the amplitude level is set at five different levels. The amplitude of the first sweep is set to the maximum output of the audio system which will give a clean 400 Hz. pre-recorded pallet tone. Each subsequent sweep is 6 dB down from the previous sweep.