High-pass and low-pass filters are used in a variety of industrial applications and consumer applications, including the testing of new technology, the building of new vehicles, and even microwaves and stereo systems. The purpose of these filters is simple: to make the passage of high and low frequency signals both easy and efficient, while blocking the passage of signals that don’t meet that filter’s criteria (for example, a high-pass filter will allow high frequency signals to pass through without a problem, but will interrupt or entirely block low frequency signals). These filters can either block the unwanted signals, or have a resistor in place to short out the unwanted signals.
If your car has a high-end stereo installed in it, or you’ve ever purchased home theater equipment, then you’ve most likely taken advantage of all that these absorptive filters have to offer. High-pass and low-pass filters are quite commonly found in audio equipment, as they are necessary to ensure that you hear only high quality bass and/or treble, depending on the setup of your speakers and the type of music you’re playing. And if you use bass boosters and amplifiers, then these filters are an absolute must, since you’ll want to deliver high quality, loud music that is also crisp and clear.