(4) Coil's Functions [Filtering] | Dear Rookie of the Coil

We will explain about one of functions “Filtering” in this time.

What is the Filtering ?
It extracts the what you need, and discard unnecessary one.

You can image the filtering generally...

• Coffee filter⇒ For blocking ground coffee beans to pass through.
• Air filter⇒ For removing dust and dirt and letting clean air to pass through.

“Filtering” for the Sound means
Extracting some components of the sound.

It only passes the specified frequency.

• Band-pass filter(BPF):It passes frequencies within a certain range and rejects frequencies outside that range.
• High-pass filter (HPF):It passes frequencies within a high range than certain frequencies.
• Low-pass filter (LPF):It passes frequencies within a low range than certain frequencies.

It’s a side note from coil...

Sound is figured by a waveform on the right.

The sound can be canceled by overlapping an inverted waveform on the original waveform.

This principle is adopted for Noise canceling headphones.

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