Simple Explanation

The range of frequencies that are allowed to pass through a filter, like a low-pass, high-pass, or bandpass filter.

Concise Technical Definition

The range of frequencies that a filter (low-pass, high-pass, or bandpass) allows to pass through. The passband is typically defined by the -3 dB points, where the amplitude response is reduced by 3 dB relative to the main passband level.

Layman-Friendly Analogy

Think of it like a fence that only lets certain frequencies of sound pass through. For example, a high-pass filter would only allow higher frequencies to pass, while the passband defines the range of frequencies that can "squeeze through" without being blocked or reduced.

Industry Usage Summary

In audio engineering, the passband is used to define the effective range of frequencies that are transmitted through filters. The -3 dB point is critical in determining where the filter begins to attenuate frequencies. For bandpass filters, the upper and lower -3 dB points define the width of the passband.

Engineering Shortcut

The range of frequencies that a filter passes, typically defined by the -3 dB points.

Full Technical Explanation

The passband refers to the range of frequencies that can pass through a filter, such as a low-pass, high-pass, or bandpass filter. The passband is usually measured at the -3 dB points, which are the frequencies at which the filter's amplitude response is attenuated by 3 dB, meaning the output power has been reduced by half. For a bandpass filter, the passband is defined by two -3 dB points: the upper and lower cutoffs, which mark the boundaries of the frequencies that pass through the filter. The -3 dB point is significant because it represents the frequency at which the output power is reduced to half of its maximum value.