Compression basics – About attack

Author: sleepfreaks

Determining how quickly the compressor hits with「attack」

After learning about「threshold」and「ratio」,


↑ we will look at determining the compressor speed with「attack」

Most compressors use 「ms (milliseconds)」as an amount to measure timing.
In computer music,「ms」is an measurement you will often see.

1ms=1000th of 1 second
1000ms= 1 second 

This is how its measured.
Make sure to memorize this!

About ms (millisecond)

What「attack does」is

determine the time it takes for the「ratio amount」of compression to be applied when the waveform goes above the「threshold」.

In the picture above the「attack time」is「7ms」
The「ratio」is at「5」.

Hence –

After「7ms」the volume will be compressed to「1/5th」.

「7ms」is a 1000th of 7seconds.
We’ve zoomed into the waveform.


↑ The ending of the area shaded in black is 7ms.
The threshold is hand drawn so just use it as an example!

Sounds that go above the threshold after that point will be compressed to「1/5th」.

「No comp」

「Attack at 7ms」

This is quite a good amount of compression.
The sound has been compressed and feels slightly pushed back.

Next is 80ms.


↑ The ending of the area shaded in black is 80ms.
After 80ms, there aren’t areas above the threshold,
so there won’t be much compression thats applied.

「No comp」

「Attack at 80ms 」

In this way, it doesn’t sound very different from the original.
There is a significant difference in sound when compared to「7ms」.

An important part of an instruments sound is its「attack」.
How you keep this in mind when mixing will make a big difference in the sound/depth of a song.

When tried above, when comparing「7ms」to「80ms」,
the sound feels a little further back.

In addition, when the「attack」is fast, the sound will quickly be squashed,
allowing for a very uni-formal volume, but might seem too squashed if set too fast.

The difficulty lies in –

「Retaining the original sound」and「having different settings for different genres」.
Even different articles and tutorials will suggest different amounts of compression.

If you want to keep the attack of the original sound (i.e. kick and snare), keep the attack time slow,
and when you want a squashed attack (i.e. guitar and synths), you can set the attack time fast.

Listen to artists and mixes that you like, and focus on the
「perceived distance」and「attack time/sound of the compression」, to try to mimic and copy that sound.

In our next article, we will take a look at「release」!