There are also three 'depths' of IDR that can be used to provide perceived resolution improvements of 6, 12 and 18dB respectively - this is equivalent to adding dither noise to the value of one, two or three bits. Typically, the perceived dynamic range can be improved by up to 18dB over what would normally be expected for undithered signals of a given bit depth - which is equivalent to three additional bits of resolution! Two IDR options are available: Type 1 produces the best distortion and linearity figures while Type 2 is optimised for the lowest noise. IDR allows high bit‑depth signals to be reduced to any target bit depth while retaining as much dynamic range as possible - a number of noise‑shaping options are available to suit different types of material. Included in the L1 was Waves' own IDR noise‑shaped dithering system developed in association with the late Michael Gerzon, a much‑respected and highly talented audio pioneer. The result of this system was that you could both limit and normalise in one operation. A third control varied the limiter's release time.
However, it was also a masterpiece of ergonomic design - the usual rash of controls was replaced by just two main sliders, one setting the peak level at which you wanted your signal to end up, and the other increasing the input gain of the signal to push it up against this limiting threshold. Essentially, the L1 Ultramaximizer was a very clever look‑ahead limiter that managed to skim the top few dBs from the peaks in your mix without introducing audible side effects. The original Waves L1 Ultramaximizer plug‑in for Sound Designer II has been a mainstay of my digital‑editing and mastering system for a number of years, yet its ability to coax increased subjective level out of an apparently 'maxed out' track never ceases to amaze me. Paul White lives life to the max with the new Waves L2, a mastering limiter with all the trimmings.