Equalisation Flashcards
What was equalisation originally invented for?
Compensating for tonal inadequacies in audio equipment
What is equalisation?
The process by which different frequency ranges are increased or decreased in volume
What are hardware EQs limited by?
The components used in the manufacture and design of the unit, including the space on the front panel for the necessary controls
What can plug-in EQs offer?
Almost limitless features and combinations of filter types
What does a filter do?
lets some of the audio signal through without changing it, but will cut or boost the signal level of a specific frequency range
On a filter, what does the cutoff frequency do?
Determines which frequencies will be passed unaffected and which frequencies will be removed
On a filter, what does the Centre frequency do?
Determines the frequency around which a band pass filter allows frequencies to pass through
On a filter, what does the gain control do?
Determine show much cut or boost is applied to the affected frequencies
On a filter, what is resonance?
Characteristic narrow boost of the frequencies around the cutoff
On a filter, what is the Q?
The width of a band pass filter or parametric EQ
On a filter, what does a high Q value mean?
The filter is very narrow
On a filter, what does the slope do?
Determines how sharply the filter will act at its cutoff frequency
What does a low pass filter do?
Reduces the level of all frequencies above the cutoff
True or False, low pass filters can be used to reduce hiss on a recording?
True
What happens to the pitch if you double the frequency?
It becomes an octave higher
What does a high pass filter do?
Removes frequencies below the cut-off frequency
What is a common use of a high pass filter?
As a rumble filter - eliminates unwanted low frequency sounds
What can a high pass filter be used to reduce the effects of?
Plosive sounds and the proximity effect
How does resonance sound?
Whistly
What does a band pass filter do?
Remove frequencies on either side of a centre frequency range
In what guitar pedal is a band pass filter used and how?
Wah Wah pedals - the centre frequency is swept to give the characteristic effect
What does a parametric EQ do?
Boosts or cuts around a variable centre frequency
What is a parametric EQ useful fo?
Adjusting the amplitude of a specific frequency range, but without altering all the frequencies above and below
What is a semi-parametric EQ?
A parametric EQ with a fixed Q/bandwidth
What could a parametric EQ cut be used to reduce?
A resonance or node
What does a shelving filter do?
Allows the user to cut or boost the signal beyond a specific frequency
What are shelving filters most commonly used on?
Consumer audio equipment and the treble/bass controls on guitar amplifiers
What can a low shelf boost be used for?
Increasing the low frequencies on a kick drum or bass guitar part
What is a high shelf boost often used for?
Bringing something forward in the mix or to add clarity to drum overheads
What do graphic EQs use to individually boost or cut specific parts of the frequency spectrum?
A bank of filters
What are graphic EQs common used in?
Live sound to correct the frequency response of a room/speaker system, and sometimes to reduce feedback
