iZotope Ozone Maximizer Rack Extension User`s Guide

Rack Extension
iZotope Ozone Maximizer Rack Extension User’s Guide
The Ozone Maximizer Rack Extension lets you create louder and fuller-sounding masters by
limiting dynamic range and boosting perceived loudness. Ozone’s acclaimed IRC (Intelligent Release
Control) limiting lets you raise the level of your mixes without sacrificing dynamics and clarity. This
Rack Extension also includes iZotope’s MBIT+ dither to ensure the highest quality when exporting
your sessions.
Key Features
• 2 Intelligent Release Control (IRC) limiter modes: IRC I and IRC II
• 2 low-latency limiting modes Hard (Brickwall) and Soft
• High-precision threshold control with integrated gain reduction metering
• Speed knob controls the character of the IRC Limiter from slow and transparent to fast
and aggressive
• Variable Stereo Link control for independent limiting of left and right channels
• Inter-sample Limiting predicts when a digital signal might clip in the analog domain,
preventing distortion
• Margin control allows you to dial back the peak output level for better encoding to formats
like MP3
• iZotope MBIT+ Dither for exporting sessions to 16-bit audio files at the highest quality
Other Resources
This User’s Guide explains the basic operation of the Ozone Maximizer Rack Extension. If you are
interested in getting some practical tips for using the Maximizer and Dither options, as well as some
of the theory behind their operation, you can also download the free guides Mastering with Ozone
and Dithering with Ozone.
iZotope Ozone Maximizer Rack Extension User’s Guide
IRC I: This mode provides intelligent digital loudness maximization of the signal. Unlike the analog
modeled limiter modes (Hard and Soft), this digital processor is designed for neutral, transparent
limiting. It does this by analyzing the source material and applying limiting in a psychoacousticallypleasing manner, reacting quickly to transients (to prevent pumping) and reacting more slowly to
steady bass tones (to prevent distortion).
IRC II: Similar to IRC I mode, however this mode is optimized to preserve transients even more so
that they sound sharper and clearer even when aggressive limiting is taking place.
Hard: This limiting mode offers low latency and CPU usage, but may introduce more distortion or
pumping than the IRC modes during heavy limiting. This mode uses the Margin control as an absolute
guide, and the final output level will not exceed the Margin setting.
Soft: This mode also offers low latency and CPU usage, and provides a natural “soft” limiting effect
at the expense of allowing the level to exceed the margin. The soft limiting algorithm uses the Margin
control as a guide but not as a fixed limit for the output level.
Note: IRC modes will introduce a slight latency, or delay, in the audio signal. Reason 6
does not have internal delay compensation. Therefore these modes will work best when the
Maximizer is placed on the Master output of your Reason session.
iZotope Ozone Maximizer Rack Extension User’s Guide
Limiting Controls and Meters
The threshold fader determines the point at which the Maximizer will begin limiting. By turning down
the Threshold you limit the dynamic range of the mix, and the Maximizer automatically adds gain
proportionally to maximize the output level.
Gain Reduction Meter
This meter shows the amount of gain reduction introduced by the Limiter in dBFS. In the Rack
Extension version of Ozone’s Maximizer, one dB of gain reduction is represented by one LED
segment. If 3 of the LED segments are lit, for example, the Maximizer is limiting the dynamic range
of your audio by 3dB.
The speed control affects how quickly the device responds to incoming audio, and can be used
to control whether the Maximizer sounds transparent or more aggressive.
Tip: The Speed control values will not necessarily behave exactly the same way in all
modes. Switching between modes may require additional tweaking to suit the audio
you are working with.
IRC Modes: When using these modes, the Speed control defines the Character of the IRC limiter,
which can range from slow and transparent gain control, to more fast and aggressive sound.
The IRC algorithms automatically vary release time depending on the audio material.
Hard and Soft Modes: In these modes, the Speed control sets the release time for the limiting
in milliseconds. In general, more extreme limiting will benefit from longer release times.
Note: The Speed, Mode and Inter-sample Limiting controls are not automatable.
Because of the way they work, automating these controls may cause audio artifacts.
They are intentionally excluded from automation for this reason.
Sets the final target for the Maximizer’s output level. If the Margin is set to 0 dB, the signal will be
boosted all the way up to 0 dB. If the Margin is set to -0.3 dB, makeup gain will be applied until the
output signal is at -0.3 dB. Note that in the Soft mode, the level may be allowed to cross the Margin
setting, while in Intelligent or Hard modes the Margin serves as an absolute “stop” point.
iZotope Ozone Maximizer Rack Extension User’s Guide
Stereo Link
Determines how the Maximizer responds to stereo audio. The control defaults to Fully Linked. This
setting imposes one limiter across the stereo image. When the control is at the other extreme, the
Maximizer does independent limiting on the left and right channels. At values in-between, a gain
envelope generated by a ratio of the individual channel and the entire stereo image triggers two
independent channel limiters. Values less than 50 favor the independent channels’ gain and
values higher than 50 favor the stereo image’s gain.
Inter-sample Limiting
Intersample mode enables “True Peak” limiting by examining not just the levels of each digital
sample, but the levels of the analog signal that will eventually be produced by D/A conversion.
This is sometimes necessary, since an analog signal’s peak level can exceed its corresponding
digital signal’s peak level by more than 3 dB! This option will increase CPU usage slightly, but if
your mixes are running very hot you may want to enable it to ensure that absolutely no distortion
is introduced when your audio is finally run through a D/A converter.
Note: Different True Peak meters have different oversampling algorithms and may produce
slightly different level readings. Ozone 5 strictly limits true peaks using its own True Peaks
measurement. For compliance with other meters, it is recommended to leave 0.1 dB of
headroom using the Margin control.
iZotope Ozone Maximizer Rack Extension User’s Guide
The Ozone Maximizer for Reason also includes iZotope’s MBIT+ Dithering. Now you can prepare
studio-quality audio for CD and other digital formats with Ozone’s essential dithering tools, without
ever leaving Reason. MBIT+ is a proprietary iZotope word length reduction technology that reduces
quantization distortion with minimal perceived noise. MBIT+ is a very smooth, quiet and almost
“analog sounding” technology that ensures the finest quality conversion to 16-bit and other bit depths.
Tip: Please refer to our online mastering guides for more information as to the technology
behind these methods and how to apply them effectively. See the beginning of this guide
for details.
Dither Controls
Noise Shape
This control shapes the dithered noise spectrum to allow for more effective and transparent dithering.
The MBIT+ dither technology lets you control the aggressiveness of this shaping, with settings that
range from None (no shaping) to Ultra (roughly 14 dB of audible noise suppression).
Bit Depth
This sets the target bit depth for the audio. When mastering for a CD, for example, you would want
this set to 16.
iZotope Ozone Maximizer Rack Extension User’s Guide
Dither Amount
In MBIT+ mode, the dithering amount can be varied from None (noise shaping only) to High. No
dithering or a Low dither amount can leave some non-linear quantization distortion or dither noise
modulation, while higher settings completely eliminate the non-linear distortion at the expense of a
slightly increased noise floor. In general, the Normal dither amount is a good choice.
Other Options
Selecting this option instructs Ozone to completely mute dither output (i.e. dither noise) when the
input signal is completely silent (0 bits of audio) for at least 0.7 seconds.
Limit Peaks
Dither noise is random in nature and has a very low amplitude. However, after noise shaping,
especially in aggressive dithering modes, the high-frequency dither noise is significantly amplified,
and the overall dither signal can show spurious peaks (up to -60 dB FS for a 16-bit quantization). If
such high peaks are undesirable, you can enable the Limit Peaks option to effectively suppress the
spurious peaks in the noise-shaped dither.
Suppress Harmonics
If is unacceptable to have dither noise at all in the processed audio simple truncation remains the
only option. This option doesn’t create any random dithering noise floor. Instead it works more like
truncation, but with better tonal quality in the resulting signal. Truncation results in harmonic
quantization distortion that adds overtones to the signal and distorts the timbre. In this case you
can enable Suppress Harmonics option to slightly alter the truncation rules, moving the harmonic
quantization distortion away from overtones of audible frequencies. This option is applicable only in
the modes without dithering noise and without aggressive noise shaping (Noise Shaping “None” and
Dither Amount “None”).
DC Offset
It is a good idea to filter out the DC offset from your input before dithering. Again, please refer to our
online guide for the background behind this.
iZotope Ozone Maximizer Rack Extension User’s Guide
Tips for using Dither effectively in Reason:
• Dithering should always be the last thing that happens in the Reason signal chain before the
audio is exported. Make sure you don’t have any Master inserts after the Maximizer. If you
want to perform fade outs or other master fader gain changes, you should place Ozo
ne Maximizer after the Master Section entirely and connect it directly to the Audio I/O section
at the top of the Reason Rack.
• When using the Ozone Maximizer’s dither, be sure to disable Reason’s own dither. When
exporting a file, you can simply un-check the “Dither” check box in Reason’s export dialog.
This will prevent Reason from dithering a second time when rendering the file. Reason will
truncate (throw away) the extra bits when this box is disabled, but Ozone’s dither will have
already converted the audio and made these bits empty.
• Currently from Reason, you will always be exporting to a 24 or 16-bit .wav or .aiff file.
Reason does not currently have options for exporting directly to some of the other bit depths
offered by Ozone (8, 12, 20). However if you want to prepare a file for these formats, you
can export a file at 24 bits with Ozone’s dither applied. Then, using an audio editor, you can
simply truncate the audio file to the desired bit depth. No additional dithering will be required
to ensure the best quality.
iZotope Ozone Maximizer Rack Extension User’s Guide
Learn more about iZotope at www.izotope.com
Copyright © 2001-2012 iZotope, Inc. All rights reserved. iZotope®, Ozone®, MBIT+™ and the iZotope
logo are trademarks or registered trademarks of iZotope, Inc. Propellerhead®, Reason®, and Rack
Extension™ are trademarks or registered trademarks of Propellerhead Software AB, used with
permission. All other trademarks contained herein are the property of their respective owners. Other
products and company names mentioned herein may be trademarks of their respective companies.
This material is provided for information purposes only; iZotope, Inc. assumes no liability related to its
use. Use of the software is subject to a related license agreement. All rights reserved.
iZotope Ozone Maximizer Rack Extension User’s Guide
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