Multi-band limiters, by contrast, divide the audio up into different bands - say low, low-mid, high-mid and high-frequency bands - before applying a separate limiter to each band and combining their outputs. Hearing everything else go up and down in volume in sympathy with the kick drum normally isn't ideal! As a consequence, you can end up with an effect called 'pumping' where a low-frequency instrument such as a kick drum forces the limiter to reduce the gain of all the elements in the mix. Single-band limiters work on the full-bandwidth audio, meaning that a peak in any frequency band will cause the level of the entire audio signal to be reduced. There are two basic types of limiters: single-band and multi-band.

These processes are being used more and more, especially in radio where everyone wants their stations to be the loudest on the dial, and we are seeing the same choices more and more in CD mastering where clients want their CD to be louder than anybody else's! Single-band & Multi-band In addition, using a limiter allows us to increase the loudness of the audio whilst maintaining the same peak level, if we are prepared to permit more frequent occurrences of limiting and therefore gain reduction of the peaks. In digital systems, as opposed to analogue tape, this is important as there is no warning of distortion: the signal is OK until 0dBFS is reached, and then it clips in an ugly fashion. Because using a limiter allows us to control the maximum signal level, we don't need to leave any headroom in the system after the limiter in case the audio gets louder than we had expected. Limiters are often used to protect transmission chains, for instance in broadcast transmitters or CD mastering, to prevent peak distortion that would occur if the audio were allowed to pass unchecked. When the input is below the predetermined level, usually called the threshold, the audio dynamics are not changed at all any input signal that exceeds the threshold level is 'limited' to that level. Limiters are audio devices that prevent a signal from going above a defined level, irrespective of the input level. But which one? We put the leading contenders to the test. If you want to get maximum level out of your Pro Tools mixes, you need a mastering limiter.

Multi band vs single band compressor