In this article, Paul Maunder checks out Audiokids Undertone 2 – a realtime ambience and texture generator, sound multiplier and drone maker, based on granular and convolution synthesis.
Audiokids are a team of three sound editors from Rome, Italy. Earlier this year we featured their handy Pro Tools AudioSuite plug-in, Dragout, which allows users to export audio files from Pro Tools to Finder or any other software or plug-in that supports drag and drop. It’s also a stereo and mono down mixer, providing a quick way to create down mixes from multi channel audio.
Audiokids’ latest release, Undertone 2, is an update to their granular and convolution synthesis based ambience and texture generator plug-in. The updates in version 2 are quite significant so I’ll do my best to cover the key features here.
What Is Undertone 2 For?
At its simplest, Undertone 2 can be used to generate ambience for dialogue fills. You can sample a short section of clean ambience in a recording and use it to generate and render a new section of any duration. Of course, this is something which can be done with other software such as the Ambience Match module in iZotope RX. Undertone 2 goes way beyond this though.
Undertone 2 is capable of generating ambiences and evolving soundscapes from short samples (as short as 150ms and up to 30 seconds long) in a natural and organic way. Thanks to the granular and convolution synthesis, it can twist and transform the source material in subtle or extreme ways. Up to 10 different samples can be used simultaneously, to create results ranging from simple to highly complex. It supports channel widths from mono up to 7.1.
Key Features
Undertone 2 is available as an AudioSuite, AAX, VST3 and Audio Units plug-in. It has two synth engines, single and multi. They can be used by themselves or mixed together.
The single engine has a limited set of controls and is very effective at generating background fills. The convolution engine provides a method for creating background fills with noise and impulse responses. It works well with constant backgrounds that have tonal content. A mix control is provided which allows you to adjust the balance of the two synths, granular and convolution. The single engine provides a pair of low and high pass filters, one for the convolved signal and one for the granular signal. Dragging one filter while holding down shift will move the opposite filter on the other signal, splitting the spectrum between the convolved and granular synths.
The multi engine offers more control over the granular synth and can use up to 10 different sounds at the same time. It also offers a powerful multi channel panner. Each slot has its own panner and settings. X and Y parameters scale the area where new grains will be spawned. A distribution control in the panner allows the randomisation of the panning to be set. When working in 5.1 or 7.1, an LFE control is provided in the panner section. There’s a path option which, when active, allows you to specify start and destination points for grains, creating movement in the sound stage.
The multi engine can generate complex scenes, musical drones, special effects and layered background fills. The probability of any given sound (or grain) playing back can be set with a slider within its respective slot. The total number of simultaneous grains is controlled in the section at the top of the plug-in and the maximum number of concurrent grains for any given slot can be set with the slot specific controls at the bottom of the plug-in. A rest time can also be applied. This sets a minimum amount of time that should pass before that slot is triggered again. For each slot, you can tweak level, pitch, randomisation, the probability that it will play back in reverse, the grain size relating to the source duration and the envelope, which is the fade in and out time. A Play From Start option is provided in each slot when you want grains to be generated from the source sample start, rather than a random position.
One effective way to use the single and multi engines in combination is to have a steady state sound in the single engine and several randomly triggered sounds loaded into the slots in the multi engine. The mixer control can then be used to set the desired balance between the two.
Sounds can be loaded into slots by dragging and dropping audio files from Finder or by clicking on the Load button for a slot and selecting a file from any location on your computer.
There’s a new Preset Browser in version 2 which provides hundreds of presets which playback from samples included as part of the tone packs installed with the plug-in. The presets can be used as they are, or as a starting point for tweaking and adjusting as needed.
Every single parameter in Undertone 2 can be automated, allowing dynamic changes over time. This provides even greater potential for variance of the generated ambiences.
There will be occasions when you only want to use a section of a loaded sound. The Sample Editor allows in and out points to be set and the gain to be adjusted. This is similar to clip gain in that it adjusts the gain of the sample prior to any level control applied by the Undertone 2 engines.
Playback sync can be set to either Host or Free. When Host is selected, Undertone 2 will follow the status of the host transport, playing and stopping with your DAW. When Free is chosen, Undertone 2 continuously generates sound independently from the host DAW.
Take a look at the video below to see Undertone 2 being used to generate dialogue fill and then to generate more in depth, evolving atmospheres.
New Features
Audiokids have added a lot of new features into this version 2 release of Undertone. Here’s the complete list of everything that’s new!
AAX/VST3/AU support
Full automation support
Dual concurrent Engines: Single and Multi play together and can be freely mixed.
Preset Browser to easily save, find and organise presets, with search, comments and tag support Dynamic grains movement: in the Panner, grains can travel on a path from a source to a destination position
AudioSuite renders are 20x faster than Undertone 1.0
Slots Overview for a quick view and control of all 10 slots
Sample Editor to edit the loaded audio files
Convolution synth supports pitch shifting and length change of the original sound
Filters in Single for the granular synth and the convolution synth
In Single, AudioSuite can use the slot name for the rendered clips
Accessibility enabled UI (in DAWs that support it)
Native Intel and AppleSilicon support on MacOS 10.12 to 12.4
Windows 8 to 11 support
Ability to load only part of a preset: Audio, Single, Multi and Panner settings and each slot independently.
Samples and presets are always resampled to the current session sample rate
Reworked user interface, larger and more user friendly
UI can be resized
New Single Engine Mini view
More than 150 new and updated presets
Auto Load in the preset browser to quickly listen and load the Presets
In Multi, new Grains Limit control per slot: set the maximum number of grains from that slot
All 10 slots can play even if not visible and can be shown independently from one another
Max grains in Multi can be set to 0: this stops the Grain generation
Drag and drop support for audio files and presets
Slots are shown when selected or ‘Pinned’ on the Slots Overview
Dry (mix Undertone 2 with existing sounds) and main output levels
Check out Audiokids’ overview video to see a demonstration of the controls and features of the plug-in.
Pricing & Availability
Undertone 2 is available now at the introductory price of €169, or as an upgrade from version 1 for €75. Introductory pricing is available until November 18th.