Multiband compression is a type of audio signal processing that combines the features of both single-band and wide-band compression. It is commonly used in sound reinforcement and recording applications to control dynamic range.
The differene between multiband compression and regular compression is that multiband compressors allow the user to split the signal into multiple frequency bands, each of which can be compressed independently. This can be useful for taming specific frequencies that are causing problems, such as sibilance in vocals or resonance in drums. It can also be used to increase the overall level of a mix without making it sound overly loud or "squashed".
While multiband compressors can be very effective, they can also be complex to set up and use. If not used properly, they can introduce undesirable artifacts into the signal. As such, they are most commonly used by experienced engineers who are familiar with their operation.
If you're looking to add some extra punch and power to your mixes, or if you need to taming troublesome frequencies, multiband compression can be a valuable tool. Just be sure to use it judiciously, and don't overdo it!