High and Low Pass Filters

The most basic filter types, these filters progressively cut the amplitude of an input signal at a selected threshold frequency. In the case of a high pass filter frequencies below a selected frequency will be progressively cut. Similarly in the case of a low pass filter, the frequencies above a selected threshold frequency will be progressively cut. As such these filters are sometimes called Cut-off Filters.

Standard Filter Types

High and Low Pass filters commonly have a gentle cut of -6 dB per octave, -12 dB per octave or a more aggressive -18 dB per octave.

It is worth noting that the circuitry used to implement filters is not ideal. This means that the gain does not suddenly change from 0 dB to -18 dB as the frequency crosses the threshold, the gain change is progressive. In fact the quoted cut off frequency is the frequency at which the gain reduction is already 3dB below the input amplitude. This point is also referred to as the 3dB Down Point.

Music Community

Click on an image to view it...


High Pass Filter
Low Pass Filter

Shelving Filters

This kind of filter applies an equal level of boost or cut to all frequencies beyond a user defined threshold frequency. Yet again the filter response is not 'ideal'

Band Pass Filters

This type of feature boosts frequencies, in a chosen bandwidth around a specified frequency. Frequencies outside this range are not allowed through the filter.

Notch Filters

Similar to a Band Pass Filter. This type of feature cuts the frequencies, in a chosen bandwidth around a specified frequency. Frequencies within the chosen band will not be allowed through the filter.

Useful Links

Discuss this article in our Music Forum.

Community boards you might be interested in:

Discussion boards

About Songstuff

Logo-dark-bg-square-170Songstuff was launch in September 2000 and has grown into an all round resource for musicians, attracting interest from musicians of all experience and skill levels. The Songstuff Songwriting and Music Community has grown into an essential, dynamic networking resource, where members exchange ideas and collaborate on common projects. Great thanks and appreciation are owed to the moderation team for helping to grow the community into the active and creative place it has become.

Site Crew conduct draw on their experience and contacts to perform interviews, and write quality articles on a variety of subjects. In addition the Songstuff Community members regularly contribute articles and Songstuff has many regular contributors from across the field of music.

Our Crew

Songstuff Site Crew are highly experienced and cover a broad range of music industry roles including label owners, music educators, professional musicans, songwriters, band managers and other music industry professionals.

This article has been written by one of the Songstuff Site Crew.

Songstuff Home Page

Contact Songstuff