Review: iZotope Neutron

Stephen Bennett tries out this new ‘virtual mixing assistant’ to see whether it really is as useful as it first sounds.

Artificial intelligences are encroaching upon professions once thought immune to automation. Expert systems now write economic bulletins, prepare law papers and compose music. Neutron, iZotope’s new plug-in, doesn’t quite try to muscle out the mixing engineer, but it does provide tools that attempt to make the process easier, more reproducible and, most importantly, quicker. Under the hood of Neutron are iZotope’s well-respected processing algorithms and Spectral Shaping technology, so there are no concerns about the sonics – but do the tools provided help or hinder the journey to the perfect mix?

Neutron comes in standard and Advanced versions, and everything you might expect from a mixing and mastering programme is available either as a standalone element or configured as a channel strip. iZotope’s compressor, EQ, limiter, Transient shaper and exciters are all fully featured, and, if you are familiar with the company’s Ozone software, you’ll have a pretty good idea of how the processors sound and the flexibility of the parameters available. Where Neutron gets interesting, however, are the automated tools that are designed to help engineers sculpt their audio to improve their mixes. Most processing software comes with presets and while ‘Lead Vocal’ and ‘Crunchy Guitar’ can sometimes be useful stepping off points for processing, it’s extremely unlikely they will be suitable for all audio passing through them.

iZotope says that Neutron’s Track Assistant is like having “an assistant engineer getting you to an optimal starting point so you can start mixing creatively”– which is quite a claim. Once Neutron is loaded onto a track, clicking Track Assist and starting playback for about ten seconds allows the program to analyse the audio and provide some starting settings for further adjustment. You can choose between Subtle, Medium and Aggressive settings alongside Broadband Clarity, Warm and Open or Upfront Midrange options. It takes a while to get the hang of how these different modes actually modify your audio, but with practice you can pretty much predict their effects. Of course, the settings created in Track Assistant mode are more your kind of “guidelines”– as Cap’n Barbossa might have it – but I found that the settings of EQ and multi-band compression were pretty much where I would have placed them by ear.

Even at the Aggressive settings, Neutron’s predictions appeared mild when auditioned on individual tracks. But, as I added the plug-in to more and more tracks, I realised that this was actually an advantage. One of the dead-ends you can find yourself in when mixing is spending time over-processing solo’d tracks and, while these often sound great in isolation they often do not fit in so well to an overall mix. Processing tracks with Neutron and then tweaking them proved to be much quicker than starting off with instancing separate plug-ins and I was extremely pleased with the results. The Track Assistant isn’t only useful when mixing – I used Neutron to process whole songs and it proved to be a godsend when I was trying to create masters with a relatively consistent sonic profile when supplied with mixes supplied by several different engineers.

That’s helpful

The Masking Meter feature is a tool that attempts to visualise frequency overlaps – something that we do all the time aurally when mixing. To do this, you instance Neutron on channels that you suspect have overlapping frequencies – for example electric guitar and vocals – and then overlay one analysed frequency curve next to the other. Neutron then indicates, via neat flashing grey bars or a histogram, where it thinks the problem frequencies lie. If the Inverse link button is on, Neutron makes complementary adjustments in the other track when changing EQ. Nodes can also be controlled via a Dynamic mode, where one node on a track can affect another, or by using side chain signals to modulate the EQ processing in the same way you would work with a compressor. It works well in practice as an indicative and processing tool for isolating common timbral clashes.

The Neutrino section offers some specific presets that utilise the underlying technology of the Neutron program and I found it quite useful to select one of the four modes – Voice, Instrument, Bass and Drums – to do a bit of ‘pre-mixing’ when collaborating via the internet. Although Neutrino is available separately as a free plug-in, the whole Neutron package makes more sense if you are serious about mixing and mastering.

Although the automated tools are extremely useful, Neutron has an extensive suite of parameters to allow the user to fine tune each section of the program. The only problem I found was that my 2009 quad-core Mac Pro was struggling with multiple instances of Neutron (Ed – iZotope says this wouldn’t be the case with a newer system), but Logic Pro’s ‘Bounce in Place’ allowed me to rapidly process a whole mix. I also tried to reproduce Neutron’s predictive settings with some of my other favourite plug-ins with some success.

iZotope’s Neutron isn’t going to put mix engineers out of a job just yet – it does not take into account the dynamic and spatial relationships that make a great mix – but pros and dabblers alike will benefit from the processing and the ‘jumping off’ points it generates. I await further developments in this area with interest and I, for one, welcome our new robot overlords.

Key Features

  • Track Assistant lets the user create a custom preset based on their audio, getting them to a faster starting point
  • Masking Meter for visually identifying perceptual frequency collisions
  • Five ‘industry-leading’ mixing processors, including an Equalizer, two multiband Compressors, an Exciter, a Transient Shaper and a BS.1770 True Peak Limiter
  • Neutrino mode for adding clarity and detail to a mix
  • Advanced version offers up to 7.1 Surround Support

From $249

Stephen Bennett has been involved in music production for over 30 years. Based in Norwich he splits his time between writing books and articles on music technology, recording and touring, and lecturing at the University of East Anglia.