RF filtering technology has been growing rapidly as the the market for wireless public communications systems such as car audio and home stereos, personal digital assistants (PDAs), cell phones and portable music devices such as CD and MP3 players. In the past, many in the automotive industry used multi layer ceramic through-hole feed thru capacitors to filter the audio amplifier output in car radios. RF filtering prevents electro-magnetic interference (EMI) from corrupting other electrical components in the car by using speaker wire or main power leads, or as a launch point for radiated noise.
The following article discussing the implementation and application of RF filtering for car audio amplifier circuits. An audio amplifier circuit required to suppress
RF interference produced by fast output transitions of the amplifier. This article is divided into following section: Introduction, Car Audio, DC Resistance (the DC resistance associated with the component reduces the power output of the audio amplifier), x2y Bypass Filter (showing application of a single X2Y bypass capacitor), Comparing RF Filter Performance, Portable Audio Devices and Conclusion.
Find more information about RF Filtering for Car Audi Amplifier Circuits here – 5 pages of PDF filetype. (source: x2y.com)