Dithering in WL85

Does anybody know how WL85 interacts with other apps, e.g. Ozone 6, when dithering a signal? WL85 has its own section and settings. Does it work independently of any other plug-in with the MBit+ algorithm? In WL8.5 Types 1 and 2 can be selected. Are they functional? Noise shaping curves can be applied. Why are curves then called “high” or “ultra”? When rendering to lower word length: Why is “Bypass Master Section” offered twice and why it is offered at all when the dithering module is applied “post master”, i. e. after the output faders? Would appreciate answers, thank you. Marcel

WL has the dithering slot after the faders because that’s where it should be; after all (internal) procesing is done. Therefor, if you use Ozone, don’t use its dithering or you’ll be dithering twice.

Thank you. Dithering is set after master faders (Options – Plug-in settings, row “Mbit + Dithering (Vst3ExternalPlugin)” the box “Post” is checked). Since there is an “None” setting in WL, I guess it would be possible to use e. g. just Ozone. Is that correct? Marcel

Yes, that can be done. BTW, the ‘None’ setting is also there for those instances where dithering is not needed.

Good. Could you also answer the other question: “In WL8.5 Types 1 and 2 can be selected. Are they functional?” Marcel

Yes they should be functional. Help > Search > “MBit+”. The different functions are described in the manual.

Thnks very much to all of you. Below is my understanding about WL 85 dithhering. The 3 noise shaping modes in internal mode are best guesses because could’nt find clear explanations. Sorry for the clumsy formatting, difficult to do in this forum.

WL 8.5 dithering modes:

• None, truncation only
• Intern, if this is selected, the three functions below become active
o No Noise, Noise Type 1 (RPDF noise), Noise Type 2 (TPDF noise)
o No Noise Shaping, Noise Shaping 1, Noise Shaping 2, Noise Shaping 3  according to manual: Clear NS (aggressively moves noise towards ½ fs, Psych5 (5th order), Psych 9 (9th order). Then NS 1 = Clear NS, NS 2 = Psych 5, NS 3 = Psych 9
o 24, 20, 16, 8 bit (quantization)
• UV22HR (default, improved Apogee UV22 algorithm), with this plug-in there are the options
o quantization 24, 20, 16, 8 bit
o dither noise levels high and low
o auto black (dither noise gated during silent periods)
• iZotope Mbit+ Dither, licensed to Steinberg WL 8 since April 2013 (licensed also to Sonic Studio, LLC of San Anselmo, CA, production tool soundBlade, already in September 2006), with this plug-in there are the options
o quantization: 24, 20, 16, 12, 8 bit
o dither types: MBit+ (white noise, max at 18 kHz, steep high pass), Type 1 (RPDF noise), Type 2 (TPDF noise)
o dither amount: with Mbit+ high, normal, low, none. If Types 1 or 2 are selected, only dither amounts 1 or 2 are being offered
o noise shaping: with MBit+ Ultra, High, Medium, Light, None. With Mbit+ only the amount of noise added is determined. If Types 1 or 2 are selected, other noise shaping setting are offered: None, Simple, Clear, Psych5, Psych 9
o Auto-blanking (no dither if audio signal is silent for >= 0.7 sec.)
o Minimize peaks (suppress spurious peaks in dither signal)
o Harmonics suppression, purpose is to move harmonics in the dither signal to the audible range. Available only in modes without dithering (“None”) and without aggressive noise shaping (“Max”, “Ultra”).

And here some specs about UV22 and MBit+ dithering noises:

• Apogee UV22, specially generated high frequency noise, no standard noise shaping, most noise occurs at 22 kHz (= ½ fs = Nyquist frequency)
• Apogee/Steinberg UV22HR, probably an improved version of Apogee’s UV22

• iZotope ™ Mbit+ (predecessor: MegaBitMax+, probably previously a commercial product used in Alexey Lukin’s ExtraBit mastering processor), flat (white random) noise if no shaping is applied), ca. 15’500 Hz to 18’000 Hz (max) dither and steep high pass, with shaping applied it is called “Mbit+ Shaping”

So WL Internal Type 2 is TPDF? How did you determine (or is that what it says in the manual)? I thought WL Internal Type 1 was TPDF.

I did newly read in the manual that Izotope Type 2 was TPDF. Didn’t know that.

In all references Type 1 is RPDF and 2 is the triangular noise version. MBit+ is most probably also based on Type 2. Gaussian noise (white) seems to be very difficult to find. The following section is from an answer by iZotope I received yesterday (from Kyle):

“Dithering types 1 (rectangular distribution) and 2 (triangular distribution), while available in Ozone 5, were removed in Ozone 6 because they were originally included in the dithering module to add mathematical variety. While this may be useful in a scientific setting, Ozone is a music mastering tool and dithering types 1 & 2 did not produce nearly as musically applicable result as a plain MBIT+ dithering. Additionally, MBIT+ is a proprietary iZotope word length reduction technology that reduces quantization distortion with minimal perceived noise. While this might sound like a paradox, MBIT+ is a very smooth, quiet and almost “analog sounding” technology.”