The dynamics elements of Power Core use relative decibels, or dBr, as opposed to dBFS. So when you are using the dynamics elements (compressor, expander, gate, limiter, de-esser), the threshold values for those elements are in dBr, not dBFS. What this means in practice is explained in more detail later. For now, it is useful to know that the threshold range will vary depending on the Relative System Level (RSL) defined in the ON-AIR Designer.