Compression

Question 1

What is compression used for?

Answer 1

Gain and volume control
Tonal manipulation
Side chain processing

Question 2

What were compressors used for in WW2?

Answer 2

Limited band width on radio broadcasts to make them travel further

Question 3

What does a do?

Answer 3

Controls the dynamic range of an audio signal - makes the louder sounds quieter and the quieter sounds louder

Question 4

What does threshold do in a compressor?

Answer 4

Tell the compressor at what point to begin processing. When the signal exceeds the threshold, the compressor will start working

Question 5

What does ratio do in a compressor?

Answer 5

The amount of gain reduction applied when the signal exceeds the threshold.
EG: if the ratio is 3:1, a signal exceeding the threshold by 3dB will cause only a 1dB increase in level at the output

Question 6

What does attack do in a compressor?

Answer 6

How long a compressor takes to pull the gain down one the threshold has been exceeded

Question 7

What does release do in a compressor?

Answer 7

How long it takes the gain to come back up to normal once the signal has fallen back below the threshold

Question 8

What is hard knee

Answer 8

Nothing happens until the signal reaches the threshold, when it reaches the threshold the full amount of gain reduction is immediately applied

Question 9

Afar is soft knee

Answer 9

The gain reduction is brought in progressively over a range of 10dB

Question 10

What is the RMS setting?

Answer 10

The compressor will ignore the occasional loud peaks and focus on consistent volume levels

Question 11

What is the peak setting?

Answer 11

The compressor will work from key transients in the sound

Question 12

What does holdtime do in a compressor?

Answer 12

Introduces a slight delay before the release phase which prevents the envelope shaper from going into release mode until the hold time has finished

Question 13

What does stereo do in a compressor?

Answer 13

Forces both channels to work together so that the compression settings are mimicked for each channel

Question 14

What is side chain compression?

Answer 14

Using one audio source to trigger the compression of another audio source

Question 15

What is parallel compression?

Answer 15

A technique which consists of splitting the signal into two. One path is the original signal and the other path is the compressed signal. Both signals at then mixed together

Question 16

What is de - essing?

Answer 16

A technique used to reduce or eliminate excessive prominence of sibilant consonants. The compression begins when the level of the signal in the sibilant range exceeds the set threshold.

Question 17

What is gating?

Answer 17

A gate is a device that mutes the signal whenever it’s level falls below the threshold

Question 18

What is multi - band compression?

Answer 18

A compressor that comprises a set of filters that splits the audio signal into two or more frequency bands. After passing through the filters, each frequency band is fed into its own compressor after which the signals are recombined