Review: Legendary Audio I.C.E.

Plug-in takes aim at distortion
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I.C.E.—shorthand for In Case of Emergency—was designed to dynamically reduce or eliminate undesirable distortion in a single, adjustable frequency band for audio. Alternatively, the plug-in—jointly developed by Legendary Audio and Sonic Studio—can boost the volume of a frequency band.

Available in AU, AAX, and VST formats for Mac OS X, I.C.E. uses iLok or file-based authorization. A Windows-compatible VST release is planned for the future. I tested I.C.E. Version 1.0.041 in Digital Performer 9.01 (DP), using an 8-core Mac Pro running OS X 10.9.5.


Fig. 1. I.C.E. addresses distortion occurring within an adjustable frequency band. The gold bar to the left of the meters shows the amount of processing applied in the band. In I.C.E.’s GUI, you drag graphical handles to respectively adjust the target (fundamental) frequency and high and low cut-offs for the band you want to treat; these settings define I.C.E.’s target frequency band (see Fig. 1). Alternatively, you can type or mouse-drag in three text-entry fields for the target and cut-off frequencies to adjust them. When you drag the target frequency using either method, the cut-offs also move. While this maintains constant offsets, careless use can also cause you to lose your current cut-off settings—and I.C.E. provides no Undo or Redo. It’s important to realize that the target frequency is merely a handle for sweeping the target frequency band; no more processing is applied at the target frequency than elsewhere in the band (a crucial point not mentioned in the operation manual).

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Toggle the Slope button to alternately choose a gentle or steep slope for the target frequency band’s cut-offs. Then mouse-drag or enter a value directly in the GUI’s Inject field to—citing the manual—apply “an amount of counter frequency” (a term and process not explained) to the target frequency band and ostensibly reduce distortion. You can also drag a round button in the GUI’s display up or down to adjust how much processing (the Inject value) you want to apply.

As I.C.E. doesn’t find distortion for you, you must use your ears to determine where in the spectrum those artifacts lay. The operation manual recommends you sweep the audio spectrum using a narrow band and gentle slope to find the frequencies where distortion occurs; I found that using a steep slope was far more precise. Activating the Monitor button solos the targeted band to aid your hunt for distortion. Unfortunately, you can’t hear I.C.E.’s processing in Monitor mode, either alone or mixed with dry signal. Although I.C.E. can only treat one frequency band at a time, you can open multiple instances of the plug-in to treat multiple bands; that’s useful when one band is more distorted than another and needs deeper processing.

Click on I.C.E.’s Boost button to enter ICE Plus mode. In this mode, instead of reducing distortion in the target frequency band, the amplitude of the band is boosted (up to 4 dB) as you progressively apply a negative Inject value. (Inject values range from 0 to -144 and are not specified in units such as dB.) Rather than use EQ to boost, I.C.E. makes a copy of the target frequency band and adds it to the original full-spectrum audio. In theory at least, this should allow bolstering weak frequency bands without incurring phase shift.

High-resolution, peak-hold meters for left and right channels show peak, RMS, and VU output levels but lack clipping indicators. (Peak-hold function didn’t work in v1.0.041.) You can name and save four custom presets of control settings for instant recall inside the GUI; copy and paste functions aren’t provided, so you’ll need to build each preset from scratch. I could also use Digital Performer’s preset system to save I.C.E. presets, but doing so prevented instant recall of presets stored in I.C.E.’s four slots (forcing me to load them via the Finder directory). And recalling a preset via Digital Performer populated I.C.E.’s current preset slot with the wrong preset name. In fact, I.C.E. has quite a few bugs. The poorly written and deficient operation manual can only be viewed on the Internet (at; Legendary Audio plans to rewrite it.


I first used I.C.E. to treat clipping distortion in a dialog track. Steep slopes yielded the most transparent processing but yielded very negligible (if any) reduction in distortion (even at the maximal Inject setting) and a slight increase in I.C.E.’s output level; because I.C.E. provides no input-or output-level controls, this sometimes necessitated upstream gain adjustments to avoid clipping the plug-in’s output. Gentle slopes ostensibly yielded much more effective reduction in distortion and preserved unity gain, but it dulled the sound. Legendary Audio suggested I use corrective EQ boost post-I.C.E. to restore presence, but doing so also fully restored the distortion. This led me to conclude that I.C.E. merely masked the distortion, much like equalizer cut would. I got far superior—and transparent—results using iZotope RX5 Advanced (a much more expensive product).

Fig. 2. I.C.E. is used to boost energy in a mix’s top octave. I.C.E. did a great job mellowing an icy, brittle mix during a mastering session. Using the plugin’s steep filter slopes and a moderate Inject setting, the mix’s edgy upper midrange and lower highs were smoothed nicely. The tradeoff was the mix had slightly less air, depth and detail. Using a second instance of I.C.E. to boost the top octave a little—using ICE Plus mode—opened the mix back up (see Figure 2). The combined effect sounded excellent. If your current arsenal of plug-ins can’t produce the same effect, I.C.E. might be worth your dollars just for this one application.

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Great for smoothing a brittle-sounding mix.

Ineffective at removing distortion. Can’t hear processing in Monitor mode or solo signal being removed. No I/Ogain controls, clipping indicators, Undo, Redo, or preset copy and paste. Buggy. Poorly written manual. Currently only available for Mac OS X.


Michael Cooper is a recording, mix, mastering, and post-production engineer, and a contributing editor for Mix magazine. You can reach him at and hear some of his mixes at