Abstract: A method and system for controlling the switching power supply in a car audio system. The system includes a circuit that detects when the signal voltage is approaching the power supply voltage rails, that is, circuit anticipates the conditions that cause “clipping” of the signal. In response to detecting the pre-clipping condition, the circuit boosts the power supply. Additionally, the inventive system includes a holding circuit for sustaining the boosted power supply for a predetermined period of time. Thus, the power is boosted as needed and remains on for a period of time thereby preventing frequent, repetitive activation of the power supply.
Abstract: An Auto Setup Program (“ASP”) may be implemented in the sound system of a vehicle to accomplish the goal of a dramatically improved audio quality achievable in any vehicle, regardless of the speaker components and head-unit utilized. The ASP performs automated time alignment measurements and equalizer processes using an external microphone. The ASP eliminates the need for expensive and time consuming professional tuning operations. The on-board ASP can be run multiple times as desired. For example, the ASP can be executed after changes to the system, such as upgrading speakers.
Abstract: An Auto Setup Program (“ASP”) may be implemented in the sound system of a vehicle to accomplish the goal of a dramatically improved audio quality achievable in any vehicle, regardless of the speaker components and head-unit utilized. The ASP performs automated time alignment measurements and equalizer processes using an external microphone. The ASP eliminates the need for expensive and time consuming professional tuning operations. The on-board ASP can be run multiple times as desired. For example, the ASP can be executed after changes to the system, such as upgrading speakers.
Abstract: An “anti-clipping” circuit for car audio systems. The circuit reduces the input voltage from a signal source to an analog-to-digital converter by using a divider or by scaling the output of the pre-amplifier to less than the saturation voltage of the ADC. A digital signal processor (DSP) with a limiter algorithm ensures that the signal never exceeds a selected threshold. Then, a multiplying block in the DSP restores the signal to the original voltage level. The anti-clipping circuit protects the speakers from high total harmonic distortion (“THD”) levels and from distortion during engine start-up. It can also be used for thermal power rollback.