Izotope Iris 2: Everything You Need To Know (Review + Guide)


Iris 2 from iZotope is making waves in the world of electronic music production with its cutting edge spectral filtering capabilities. Spectral filtering is a new way of “drawing” filter regions directly onto a spectrogram, allowing you to make filter movements that would be impossible to achieve with traditional equalizers and filters.

While this sounds amazing on paper, is it only good for making drones and pads? In this article, we’re going to take a look at some of the pros and cons of this plugin, so you can get a better idea of what’s in store for you before you take the plunge.

Notable Features of Iris 2

Spectral Filtering

What makes Iris 2 stand out is, most notably, the four oscillators, which are represented as spectrograms. Rather than displaying the waveform as a snapshot of amplitude over time, a spectrogram shows a sound’s frequency content over time (the frequency spectrum is mapped to the y-axis and the time is mapped to the x-axis).

On the left of the oscillator sections are some controls you can use to isolate different regions of the graph. For example, you can isolate one or more bands of frequencies, one or more time regions or both. You can even draw in your own shapes, isolating random frequencies at will. This feature gives you the highest degree of filter control in the spectrogram itself! The more complex your spectral filtering is, the harder it becomes to replicate using traditional filters.

Time Selection Tool

The first spectral control on the left is the time selection tool. This tool allows you to drag horizontally to select a duration of time to loop. However, you are not limited to selecting just one region. You can select a series of regions to have multiple time selections, which for example can be used to achieve a stutter effect.

Frequency Selection Tool

The third control is the frequency selection tool, which allows you to drag vertically to select individual bands of frequencies. And this is the essence of Iris 2. You can select several bands of frequencies across the frequency spectrum, something that is virtually impossible to achieve with traditional equalizers and filters.

Frequency and Time Tool

The spectral control in between these two is the frequency and time tool. This one allows you to drag both vertically and horizontally, essentially cropping different sections of the sample. Just these three tools used in combination offer endless possibilities that, if you were to try using old school filters, would take a very long time to achieve through tons of automation and parallel processing!

Lasso, Brush & Magic Wand Tools

But there are three more tools to give you even more control over your filtering. The lasso tool allows you to draw random shapes anywhere in the sample. The brush selection tool allows you to trace out fluid paths through the sample. And the magic wand tool helps you isolate specific harmonic regions through intelligent selection!

With four spectrogram oscillators and a massive sample library to work with, you already have infinite possibilities right off the bat, and we haven’t even started looking at the other features!

Modulation Controls

Below the spectrograms are the modulation controls – five low frequency oscillators (LFO’s), five envelopes, five MIDI controls (key tracking, velocity, aftertouch and mod wheel) and eight macro controls. For the most part, these modulators are pretty standard like the ones you would find on most synths.

But it’s the LFO’s that deserve special mention in these sections. Instead of static waveforms, the LFO’s have wavetables that can be modulated or automated just like a standard wavetable oscillator! There is one set of wavetables in particular called “Multiply” which contains all the basic wave shapes but allows you to multiply the number of cycles using the wavetable slider. This could be used as an FM modulator when applied to the pitch, but imagine what it could do when applied to pretty much any other parameter in the plugin!

Sample Controls

To the right of the spectrogram and modulation controls are the individual sample controls. These are your basic sample selection, tuning, and send effect controls, and this is where the first drawback comes into the picture. You can only use either the send effects on each sample or the master effects on all four at once. It may not be necessary to have the option to use both send and master effects but it would be nice to be able to apply, for instance, a reverb to “glue” the sounds together.

Master Controls

To the right of the sample controls is the master section. This section contains the master gain, pan and velocity settings, a spectral display of the final output, a master filter and the master effects. And this brings us to our second drawback. The only filter available is the master filter. Again, this might seem like asking for too much since there is already so much filtering capability in the spectrogram, but it couldn’t hurt to have individual filters for each sample.

The filter shapes are the standard ones – low pass, high pass, band pass and peak – with subtle variations for each shape such as New York, Tokyo, saturated and more. In the filter’s drop down menu, we come to another pain point. When you hover the mouse over one of the options, it displays a small line of text with a little more detail of what that option offers, but this line can obscure some of the filter options from view, which can get annoying pretty quickly.

User Interface

Iris 2’s interface is highly accessible with 90% of what you need available on the main screen. The modulation controls work a lot like Massive or Serum, where you drag the little plus sign next to the modulator to one of the parameters on the UI and then drag up or down to adjust the range. This is by far the easiest and quickest way to apply modulation, and also the most visually intuitive.

There is a virtual keyboard at the bottom of the plugin that displays the root note of the sample that is currently selected. By default, the root note is auto-detected, so most of the time you will be ready to play a pitched sample in the correct key. You can also collapse the keyboard, modulation, sample and master controls to increase the size of the spectrogram section, in case you need to make very tiny adjustments to your spectral filter shapes.

Drawbacks of the User Interface

However, there are a few points of concern when it comes to navigating the user interface. The first one is the spectrogram itself. Very often, after drawing a few shapes into the sample, the cursor will start to lag while moving around the spectrogram display. This usually happens during playback but it is extremely distracting when it happens.

Also, the controls for the effects are housed in a kind of drop-down window next to each effect, which can only be closed by clicking on the X at the top right corner of the window or by clicking on the drop-down button itself. This is not such a big deal but it would be smoother if we could just click anywhere outside the box to close it.

Is iZotope Iris 2 worth it?

At $149 USD on the iZotope website, this price is pretty standard for a plugin of this caliber. Other popular plugins like Massive and Ana2 are in the same price range, and some plugins like Serum are more expensive. Serum is a great plugin but it’s not exactly one of a kind anymore with so many wavetable synths flooding the market lately. At the moment, Iris 2 is currently the only synth with the spectral filtering capabilities that it offers.

Also, it has already been put on sale at least twice at Plugin Boutique, of which the second time it was given for free during Black Friday month! So even if you don’t think it is worth $149, you will probably get it at a hugely discounted price from Plugin Boutique or another plugin store in the near future.

iZotope Iris 2 CPU usage

As mentioned earlier in this article, Iris 2 does show some performance issues such as the mouse cursor lagging during playback. This is primarily because of the complexity behind the spectral filtering and the modulation controls. As you can probably imagine, these features require tons of complex calculations and data streams to happen almost instantaneously for the plugin to work correctly, resulting in a significant strain on your computer’s resources.

There are ways to work around this though:

Increase buffer size.

All DAW’s have the option to increase the sample buffer size. Doing so will increase latency, causing a delay between a note trigger and the output, but will greatly help your CPU handle the stress. The only time you need a low buffer size is when you are recording to a click track or a backing track so that the performer can keep time with the project. For electronic music production, you can keep the buffer size at its highest to help reduce the strain on your computer.

Hide the user interface.

Iris 2 has a ton of real-time metering on the user interface, including modulation dots that move around the modulation destinations during playback and a spectrum analyzer on the master section. Since these graphics occur in real-time, they will take up a lot of your computer’s resources. You can hide the UI by clicking the arrows next to each section’s heading tab to close them all. This will conserve 2-3% of your computer’s processing power.

Freezing or bouncing tracks.

This option is probably only available at the end of your sound design and composition process because it involves bouncing or recording your MIDI loop to an audio channel. Once you do this, you are committed to whatever you recorded especially if you delete the MIDI channel that contained your sound. However, this has a substantially positive effect on CPU usage and should be done for other CPU intensive plugins as well.

Reduce your voice count.

Voice count refers to the number of instances of the sound being played at once. This could mean the number of notes being played at once in the case of chord progressions or the number of unison voices applied for stereo width or both. The higher the number of voices, the more strain on your CPU. While this can affect your creative process, there are things you can do in this regard to help conserve your computer’s resources. For example, you can set your bass and lead sounds to mono so that consecutive notes don’t bleed over each other during the release phase of the envelope.

Reduce envelope release times.

Similarly, if you are creating a sound that has a long release that is meant to bleed into subsequent notes, it will help to reduce the release time a little bit to help your computer keep up.

Reduce sample distance from original pitch.

Iris 2 has two algorithms called Radius RT and Resampler, which are there to help detect the root note of the sample. When you play notes that are very far from this root note, it requires the plugin to make more calculations resulting in a higher impact on your computer’s performance. It is generally best practice to stay within an octave above or below the root note to avoid this.

Avoid the most resource-intensive filters.

Iris 2 comes with some boutique filter models such as New York and Tokyo that use up to 4% more CPU power than the rest. Avoiding these filter types will help ease the pressure on your CPU.

iZotope Iris 2 vs Serum

When Serum was released, it took the electronic music world by storm. It introduced a whole new way of working with wavetables and introduced the capability to create your own wavetables. Since its release, Serum has pretty much dominated as the most popular VST synth and likely still does. While Iris 2 offers such an amazing innovation with its spectral filtering, Serum is still a much more intuitive synth in its user interface design.

However, that does not mean that Iris 2 cannot hold its own. As covered in the beginning of this article, Iris 2’s spectral filtering capabilities are cutting edge and one of a kind. To replicate the things you can do with Iris 2’s spectrogram using even the most advanced traditional filters and equalizers is pretty much impossible.

Modulation Features

The modulation in Iris 2 works in a similar way to Serum’s modulation – you drag a modulator and drop it on a parameter, and you’ll see the range of the modulation light up the edges around that parameter. To adjust the range, you need to click and drag up and down. But it’s the modulators themselves that stand out in both plugins.

Serum’s LFO’s are completely customizable in that you can draw your own LFO shapes no matter how complex or random. This has been one of Serum’s strengths since the beginning. However, Iris 2 LFO’s, although not fully customizable, are wavetables themselves! This means that you can modulate the shape of the LFO’s themselves to create more variation in your sound.

FM Anything!

Another aspect of Iris 2’s LFO’s is the set of wavetables called “Multiply”. These wavetables are your standard waveshapes (sine, sawtooth, etc.) but the wavetable position slider will multiply the frequency of the waveform to a very high degree, offering an FM kind of effect on any parameter in the synth that can be modulated!

Also, one instance of Iris 2 offers up to four oscillators, all of which have the same spectral filtering capabilities. This gives the plugin a huge advantage over other plugins, most of which have only two oscillators and some only three. With four times the spectral madness, Iris 2 is possibly the most versatile soft synth plugin out there.

However, one thing that seems to be becoming an issue for a lot of producers (including me) is that it seems to be pretty restricted to making pad and drone sounds. This is not to say that it is meant only for that – the sounds library has everything from synth and instruments samples to atmospheres and real world objects – but the best results seem to come up only in the pad/drone area. So far, it seems very difficult to design a good, usable bass or lead sound, which is a bit of a downside to this otherwise amazing plugin.

Overall, Iris 2 is a great synth for sound design that may be aimed at the more intrepid sound designers among us. If you are looking to experiment with sounds in a whole new way simply for the sake of “seeing what happens”, then this synth is an absolute must-have. But if you are more of a songwriter in that you would like to get the best results for your music as soon as possible, then this may not be the plugin for you. Either way, Iris 2 offers some great innovations for its price and is totally worth a buy.

Mori B

I'm a music producer, a dj and a blogger.

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