tags: music compression mus-407 production dynamics drp dynamic-range-compression dynamic-range

Compression

Compression is a form of [dynamic range control] that (generally) reduces the [dynamic range] of a signal. A compressor is an amplifier whose gain is determined by an input [signal] level

• when signal level > [amplitude] threshold, compression effect becomes active and attenuates a signal

Frequently used to regulate a "peaky" signal during recording, i.e. to provide a more constant and predictable level

• e.g. rock drum set, swaying vocalist
• essentially, automates [mixer] input faders to avoid manual adjustment

Compression is also used during mixing/mastering to provide a higher overall mix level.

Compressor behavior is modeled using a graph of its [transfer function], which is generally comprised of these parameters:

• [ratio]
• [threshold]
• makeup gain
• attack/release

Compressors can also feature the following additional parameters:

• auto mode
• lookahead
• stereo linking

Ratio

The severity of signal attenuation is determined by a compression [ratio].

Downward compression ratios of 8:1 and above are generally considered "extreme" compression

• Can result in a perceptual distortion of [transients], noticeable changes in [timbre], often described as a "squashed" sound
• A compressors with ratios above 10:1 would generally be considered a [limiter]

Makeup gain

After compression is applied, makeup gain is a normal amplification process used to compensate for the loss in overall level

• typically used to restore peaks to their original level after compression creates more [headroom]
• content below threshold, including the [noise floor], undergoes a net level increases

Types of Compression

• [Limiting]
• [Upward compression]
• [Multiband compression]
• [Parallel compression]
• [Buss compression]
• [Sidechain compression]
• Serial compression

Sources

• MUS 407 Dynamic Range Processing
• https://www.blackghostaudio.com/blog/the-ultimate-guide-to-compression