iZotope Neutron 4 review

The AI mixing package is back for its fourth incarnation. We sum up the new additions and replacements

  • $399
iZotope Neutron 4
(Image: © Future)

MusicRadar Verdict

Neutron can find a use at the heart of anyone’s mixing setup – from beginners to pro producers.


  • +

    Unmask module provides instant mix readiness.

  • +

    Exciter is much more versatile.

  • +

    Assistant View is great for beginners.


  • -


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iZotope Neutron 4: What is it?

Since Neutron 3, which first hit the virtual shelves in 2019, iZotope seems to have taken some time to mull its next steps with the plugin. Neutron 4 takes what was already a sophisticated suite of mixing tools – compression, EQ, transient shaping, distortion and the like – and offers some enhancements, some additions and some new ways of working. The artificial intelligence bent is still evident throughout, but it doesn’t make itself a compulsory part of the experience.

At a glance

Supported hosts: Logic Pro, Ableton Live 10.1 - 11, Pro Tools 2021 - 2022, Cubase 11 - 12, FL Studio 20, Studio One 5, REAPER 6 and more 

Price: £343/$399 

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Chief among the new additions is the Assistant View, a new, simpler and more intuitive window for making crucial changes to a channel’s sound. A key part of this view and workflow are the new Punch mode on the Compressor module and a beefed-up Exciter module. Elsewhere, there’s an Unmask module to quickly get a sound out of another sound’s way.

iZotope Neutron 4

(Image credit: iZotope)

iZotope Neutron 4: Performance and verdict

Assistant View gives Neutron users a new way of working. Activate it and you’ll be asked to start playback, after which Neutron will crunch the numbers and come up with a set of modules – and requisite settings – as a starting point for your mix.

Assistant View identifies the instrument you’re using and offers four key areas that, in theory, should play the most crucial part in shaping your sound: Tone Match, Punch, Distort and Width. The whole window is well set up and easy to make sense of for broadstrokes changes or beginners. The ‘old-school’ view of your loaded modules and their full parameter sets is still available, only now this is known as Detailed View.

The Assistant View controls are all actually macros that command particular features of the modules added to the processing chain: Tone Match operates a Sculptor’s amount to make the track conform to an ‘ideal’ spectral response, Punch operates the controls on the new Punch compressor (more on that elsewhere), Distort commands the Exciter module behind the scenes, and Width controls the output Width control of the chain.

These four processing areas might not sound like they’ll play the most crucial role in the mixing experience – “Hey, where’s my EQ and vintage compressor??” – but in use, the results prove the choices are a very reliable and effective way to get a solid first mix.

iZotope Neutron 4

(Image credit: iZotope)

Unmasking made simple

Neutron’s newest module, Unmask, offers a quick and easy way to get a sound out of another’s way. While Neutron was already equipped with a masking view as part of its EQs, the idea here is to load Unmask onto a sound (eg a piano) and sidechain in the sound (eg a vocal) that you want to make space for.

In use, Unmask works very well. Not only can you simply and quickly officiate the competition between two sounds, you can set how strongly this is done (Sensitivity) and define the Attack and Release times of the effect. Vocals are, in particular, effectively brought out when sidechained into competing channels (send the vocal to the sidechain pre-reverb for better results). Even kick and bass can be tidied up very effectively using the Unmask module, although the process takes a little longer in fine-tuning Attack and Release times. 

Unmask is a true candidate for replacing multiple tools in your current mixing workflow. Not every time does it do a better job than a human with several plugins on-hand, but often it’s all you need for the solid separation of two parts.

The overhauled Exciter

In an impressive feat, multiple upgrades have been made to the Exciter module, all eminently useable. The original X/Y pad, which blended between four distortion types, has been boosted with a second mode: Trash. This takes four new distortion types out of iZotope’s Trash 2 distortion plugin, giving you the option to blend between Clipper, Overdrive, Scream and Scratch types, representing a versatile selection of signal mashers.

Also consider...

IK Multimedia MixBox

(Image credit: IK Multimedia)

IK Multimedia MixBox
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FabFilter Total Bundle
Bleeding-edge but highly, highly creative and professional mixing tools. The price is higher, but then so is the quality and the user experience.

Sonible Smart: range
With AI-assistive tools for mixing – EQ, compression, limiting and even reverb – Sonible are worth a second look.

A Tone control has been added, providing a better way to take the edge off distortion than the high-shelf filter (which still remains). This control lets you weight any distortion type to put the emphasis towards lower or higher frequencies. In use, it’s very handy, letting you back off an overzealous high-end or deliberately add more weight and punch to the lows. Considering that the whole Exciter module is multiband-capable, though, Tone can feel like a slicker and simpler response to a question iZotope had already answered.

The Exciter’s Tame button delivers another way to dial things back, but this time with the intention of preserving dynamics. In use, the result is often a crisper sound that, while still nice and fuzzed up, retains its musical and rhythmic edge. 

With Tame and also Tone, it’s possible to push the distortion algorithms harder than before to introduce an intense character, safe in the knowledge that you can keep things musical, intelligible, and most of all, classy.

The Compressor module has also been boosted with a new mode. Punch mode eschews traditional controls like Threshold and Ratio in favour of a modern approach to dynamics, with a general ‘amount’ control (bipolar to increase or decrease dynamic range), and Attack and Sustain controls for a more transient-shaping approach. 

The Punch compressor achieves exactly what it sets out to – it’s a quick, easy-to-use set of controls for adjusting a signal’s dynamic range, and sculpting the onset and body of the signal. As a first port of call or a quick-and-dirty solution for these jobs, Punch mode is all you need. Consider it another tool in your selection of dynamics effects, and one that’s just as competent as the next compressor or transient shaper.

Neutron star

These new features bring a few new tricks to Neutron, and most will be a little more appreciated by those looking for simpler takes on complicated concepts, rather than those who want to fully micromanage their signal processing. In particular, Unmask is a joy for quick mixing, and the Exciter now feels like a comprehensive distortion toolbox. Neutron v3 users should seriously consider the upgrade, and the package is still a solid – if expensive – choice for novice mix engineers.

MusicRadar verdict: Neutron can find a use at the heart of anyone’s mixing setup – from beginners to pro producers.

iZotope Neutron 4: The web says

"Although the AI mixing is still a little hit and miss and there are a few missed opportunities, it’s a decent upgrade and remains a powerful all-in-one mixing tool."

iZotope Neutron 4: Hands-on demos


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iZotope Neutron 4: Specifications

  • KEY FEATURES Assistant View provides easy-to-use, macro-led controls over AI-assigned paramters, Unmask module to help carve out space, overhauled Exciter with new algorithms and settings, Compressor Punch mode for modern dynamics control.
  • CONTACT: iZotope