Make-up gain is used to turn the overall level of the signal back up. The level of the signal coming out of a compressor wonвЂ™t be as high as it was when it went in because the compressor is actively turning down parts of the signal. вЂњBass guitar and vocals would sound better using a soft knee, but I would use a hard knee for any kind of percussive instrument, like the piano or kick drums,вЂќ says producer, engineer, and mixing artist Gus Berry. A soft knee will sound smoother because the compression doesnвЂ™t begin as quickly, while a hard knee will sound more dramatic. The knee is how quickly the compressor transitions from not compressing the signal to compressing it. However, extreme compression with a fast release time can result in a pumping effect - or a sudden increase in volume - that can make the track sound uneven in some genres of music. At low levels of gain reduction, fast release speeds sound the most natural. The release time is how long it takes the audio signal to revert from being affected to uncompressed. вЂњSo you can set a slower attack to create some punch from an instrument thatвЂ™s softer, like a keyboard, or a fast attack to quickly compress the sound of a loud guitar pick.вЂќ

вЂњItвЂ™s going to affect the first part of the sound you hear,вЂќ says Rodocker. The attack time is how long it takes the audio signal to be fully compressed to the ratio set after it has crossed the threshold. Peter explains that вЂњthe volume of audio is measured in decibels (dB), so if you set a 3:1 compression ratio, every 3dB of input signal above the threshold will produce 1dB of output signal.вЂќ The ratio is the amount of attenuation - or downward compression - that will be applied once a signal reaches the threshold. You would want the compressor to be set where the threshold grabs only that loudest part of the track,вЂќ says Rodocker. вЂњImagine a guitarist thatвЂ™s strumming at a constant volume, then hits a few notes super hard in the middle of the song. Once a threshold level is set, any audio below the threshold will be unaffected, but any audio above the threshold will be compressed by the ratio set. The threshold is the level at which compression begins. Understanding the technical aspects and terminology of audio compression will allow you to work more comfortably with a wide range of compressors. The fundamental controls of audio compressors.

Types of audio compressors