I read an effects chain in a video, can someone explain what it means?

Question

I read an effects chain in the description of this video.

It said, "The stutter effect on the strings is accomplished with a hard compressor sidechained to an inaudible source."

Can someone explain what that means?

Answer 1

The stutter effect on the strings is accomplished with a hard compressor sidechained to an inaudible source.

• Stutter effect - This is probably clear - it's the name for the way the strings sound when they are processed as described.
• Hard compressor - A compressor processes audio to make it quieter when the key signal gets louder. A "hard" compressor is set up so that it will make the processed audio infinitely quiet (turned off) based on a small amount of key signal. Usually the key signal is just a copy of the processed audio, so that when the audio gets loud, the compressor dials it back a bit and keeps it at about the same volume. Sometimes, the key signal is actually something totally different...
• Sidechain - A sidechain is a separate input to a compressor that lets you use a key signal that is different from the audio that you are processing. One popular way to use a sidechain is to take a copy of some singing or dialog audio and connect it to the sidechain input of a compressor that is affecting a music track. When the person talks or sings, the sidechain signal makes the music quieter. You can hear this all the time on the radio or advertisements. Usually the sidechain signal is a copy of audio that is also being played along with the compressed signal, but not always...
• Inaudible source - This is an audio signal that is plugged into the sidechain and nowhere else. You can't hear it because it's not mixed into the rest of the music. The sidechain input is a dead end, it just controls the compressor. We can guess what the source would sound like if it were audible. It's probably like a repeated drum hit or noise burst at the same rate as the stutter effect. Every time the hit or burst goes into the sidechain input, the strings are compressed to almost silence by the compressor. When the hit or burst is done, the compressor releases and the strings come back up. The repeated hits or bursts are making the compressor compress and release really fast, creating a stutter sound.