As we saw earlier, when a compressor's ratio is set to infinity, it will act as a limiter, completely preventing a signal from going above the threshold setting. However, dedicated limiters will generally be much better at this job. In the context of mastering, limiters are usually used for two purposes - to raise the apparent loudness of the audio without affecting its sound, and/or to block peaks from exceeding the limits of the destination media and causing distortion or 'clipping', or in the case of vinyl, causing the stylus to jump out of the groove! When mastering for CD, following compression with limiting is standard practice, while any projects destined for television or radio will usually have to follow strict guidelines as to their level requirements, and so audio engineers use limiters across their master outputs to ensure that they are met.
Waves L1 Limiter Plug-in