Multiband Compressor

A compressor is an audio tool that helps alter a signal's dynamic range by reducing the volume of louder parts or by amplifying quieter parts. It is, without a doubt, one of the most important tools in the modern audio world. This blog will discuss an exceptional type of compressor called the 'Multi-band Compressor.' 

What Is Multi-Band Compression?

A Multi-Band compressor splits the frequency spectrum into several frequency bands (Usually 4) using bandpass or crossover filters. Each band is then provided with its own compressor with functions like Threshold, Attack, release, ratio, and makeup gain. This way, one can have different compression settings for other frequency ranges, making it a handy device. A lot of these compressors also provide a solo button for each band. This is very helpful because you can easily hear and manipulate the compression on each part of the frequency spectrum.  

Why Is It Helpful?

Full-bandwidth compression benefits audio signals with narrow bandwidth, like vocals, guitars, bass, etc. It affects the whole frequency spectrum and does not cause any anomaly on signals with a narrow frequency range. On the other hand, if the signal has a wide frequency range, we need a compressor with different settings for different frequency ranges, enabling effective compression without any anomalies.  

For Example:

There is a two-track recording, a kick drum, and a bright acoustic guitar. If we put an entire bandwidth compressor on it with a short attack, the guitar will sound fine, but the kick drum will sound boxy and choked. The reason is that the kick drum's low end will not have enough time to be heard before the compressor kicks in. On the other hand, if the same compressor is set to a longer attack, the kick will sound fine, but the guitar will sound harsh because the peaks will not be tamed with the high attack time now if we introduce a Multi-Band Compressor. We can have a longer attack in the lower mid band for the kick to sound right and a shorter attack for the upper mid band for the acoustic guitar to sound right. Hence solving the issue.

Common Controls on a Multi-Band Compressor

• The frequency band selector: The part helps to select the frequency ranges for different bands. Thus giving customized control over the bandwidth. It also has the makeup gain function for each band.

• Compression settings for each band: Each has a setting like Attack, Release, Ratio, Threshold, solo, and bypass.  

Some Applications of a Multi-Band Compressor 

• Mastering: It is a very common tool used for the mastering process. Some people also call it the 'secret tool' of a mastering engineer. It adds an exciting flavor to the whole mix. Significantly boost the low end and make the high end crisp and smooth. One important thing to remember is to use lower ratios because a little can sometimes be too much.

• Drums: Drums have a wide frequency spectrum and are often processed using multi-band compressors.

• Vocals: Even though vocals have a narrow bandwidth, a multi-band compressor can still be used to alter a specific range of frequencies and thus have a very cool effect on the vocals.

• De-essing and De-popping: Multi-Band compressor has a wide application as a 'dynamic equalizer.' It can cut down the sibilance within a specific range of frequencies only if the signal exceeds a certain threshold. This is not possible with a 'static equalizer' because it will do so for the whole track.