‘ab Decoder’ HOA
Audio Brewers ab Decoder HOA is a collection of plugins designed to manipulate, transform and decode Higher Order Ambisonics signals automatically to multiple speakers arrays.
The set of plugins was made with ease in mind - where the user simply inserts the plugin, and it will automatically work without the need to spend countless hours tweaking settings.
ab Decoder HOA also comes with a ‘smart troubleshooting’ algorithm, which will check your signal chain and let you know if something is wrong with it.
The plugins are not only compatible with all Audio Brewers libraries, but also with any 1OA-7OA signal*.
The plugins come in VST/AU/AAX format and are compatible with any DAW that can support multichannel audio/instrument tracks.
As of today, the list of supported DAWs is:
Pro Tools | Ultimate
Reaper
Cubase Pro
Nuendo
Logic X
Max
A Windows and Mac OS version is available.
Additionally, a free version of the plugin is also available, apart from allowing you to rotate the signal, it will decode it to Stereo (or Headphones).
Audio Brewers ‘ab Decoder Light’ (Free)
ab Decoder Light is the free version of the decoder, which automatically adapts the input signal (Ambisonics) to Stereo/Headphones Stereo.
A Rotation Control helps the user rotate the signal in the spatial field (true panning)
An Azimuth and Elevation control allow the user to flexibly place the speakers at different positions in the spatial field.
This plugin might be enough to those composers, musicians and sound engineers who work in with Stereo signals.
ab Decoder HOA includes:
ab Decoder HOA
This plugin decodes you Ambisonics signal to several speaker-array configurations from Stereo all the way to 9.1.6 (depending on your DAWs support).
The plugin adjusts automatically its input and adapts the decoding algorithm depending on the signal being 1OA, 2OA, 3OA, 4OA, 5OA, 6OA or 7OA*.
Depending on the DAW’s Output, the plugin automatically selects the optimal order used to decode (you can also manually select between 1OA-7OA or Automatic).
The plugin adjusts automatically to your DAW’s output (depending on its support). From Stereo, all the way to 9.1.6.
Additionally, it offers Azimuth and Elevation controls per speaker (or speaker pairs) to manually adjust the location of the sound sources.
A SOLO/MUTE button allows the user to monitor specific speaker groups of the decoded signal
Finally, a High-Pass filter as well as a Gain control are available for each segment of the selected Speaker Array.
This plugin includes a HOA Rotation control, so if you want to simply decode your signal without a long chain of plugins, this would suffice.
An LFE control is also included in case the user wants to route some of the Low Frequencies to the LFE channel (when available)
ab Rotator HOA
This plugin is designed to rotate the signal in the spatial field (true panning). It doesn’t decode the signal, so it inputs and outputs an Ambisonics signal (1OA, 2OA, 3OA, 4OA, 5OA, 6OA, or 7OA, depending on your track’s properties*).
Rotation can happen in the Y (left/right), X (up/down), and Z (diagonally) axes.
ab Rotator HOA automatically detects if your signal is 1OA, 2OA, 3OA, 4OA, 5OA, 6OA or 7OA*, and then rotates it!
How to decode Ambisonics audio files in Avid Pro Tools Ultimate?
How to decode Ambisonics Sample Libraries in Avid Pro Tools Ultimate?
How to decode Ambisonics audio files in Steinberg Nuendo or Cubase Pro?
How to decode Ambisonics Sample Libraries in Steinberg Nuendo or Cubase Pro?
How to decode Ambisonics audio files in Cockos Reaper?
How to decode Ambisonics Sample Libraries in Cockos Reaper?
How to decode Ambisonics audio files in Presonus Studio One?
How to decode Ambisonics Sample Libraries in Presonus Studio One?
‘ab Decoder Light'
The free version of the ‘ab Decoder’ comes ready to decode any 1st Order Ambisonics signal into Stereo and Stereo Headphones. Additionally, rotation controls are included to manipulate the signal’s rotation before it’s decoded and thus, achieve what we call ‘True Panning’.
Compatibility:
Input:
This plugin should always receive a 1st Order Ambisonics (4-Channel) Signal. Depending on your DAW, your track’s properties will be different, please refer to your DAW’s section of this guide.
Output:
Additionally, this plugin will always Output a Stereo signal (2-channels).
Rotation:
The Rotation Controls help rotate the Ambisonics signal three-dimensionally. This transformation happens internally before the signal is decoded to stereo, thus, all the sonic properties of the sound are transformed and retained accordingly.
ROTATION can be quickly turned on and off by clicking on the Toggle button (in blue), however, as soon as the user modifies any of the rotation sliders, Rotation will automatically turn on.
Three sliders (in yellow) offer the user the option to rotate the signal in three axes:
Z-axis (left), is a rotation as if your head was moving from left to right.
X-axis (middle) is a rotation as if your head was looking up/down
Y-axis (right) is a rotation as if your head was moving diagonally over the Y-axis.
The visualiser helps the user see the resulting sound after it’s being rotated, this can be useful keep a visual track of where the sound is coming from.
What is true panning?
‘True Panning’ is a concept that came to us to differentiate ambisonics rotation from the traditional stereo panning. When panning in stereo, the user is simply sending one channel to another so the sound is simply moving to that direction the hard way - the sound remains static and there can be problems in the acoustics if each of the channels contains phase differences.
‘True Panning’ rotation grabs the three-dimensional signal and rotates it around the person’s head, transforming the way the sound behaves in the same immersive mix. As an example, a piano’s leftmost key and a rightmost key shouldn’t sound in the same spot if the piano is hard-panned to the left, when you place a piano to your left, the leftmost and rightmost keys still contain a stereo image as the sound arrives at your head at different times and with different reflections. With ambisonics, because all the three-dimensional information of the recording is retained in the signal, the sonic results are just like in a real-life environment.
Rotation can be applied in three directions: When you rotate your head over the Z axis (i.e. you look left/right), the X axis (up-down) or the Y axis (diagonally). In other words, you could place a piano on top of your head - sonically speaking :)
Decoder:
The decoder itself works automatically to decode the signal to Stereo.
A type of stereo decoding can be chosen by clicking on the menu (yellow) and selecting from the options. Additionally, the location of the sound source can be modified by widening or narrowing the distance between the speakers and their height from the head (green).
As the location is modified, the visualiser can be used to help spot where the sound is coming from (blue).
The difference between Stereo and Headphones Stereo is that whenever the speakers are less than 90 degrees apart, the ‘Headphones’ polar pattern of the sound sources is more directional than that of the ‘Stereo’.
Meters
The meters are here to keep track on the levels and the results of both the input and output signal.
Additional
The buttons are available to reset the window size, toggle between dark and light mode and display an ‘About’ window of the plugin. The plugin can be freely resized by clicking and holding from the bottom-right corner.
‘ab Rotator HOA’
‘ab Rotator HOA’ is a plugin that can be inserted in any 1st, 2nd or 3rd order Ambisonics chain.
Compatibility:
Input:
This plugin should always receive a 1st through 7th Order Ambisonics Signal. Depending on your DAW, your track’s properties will be different, please refer to your DAW’s section of this guide.
Output:
The plugin’s output is a 1st through 7th Order Ambisonics signal (depending on your track’s width), so make sure you insert it BEFORE the decoding happens.
Rotation:
The Rotation Controls help rotate the Ambisonics signal three-dimensionally. This transformation happens internally before the signal is decoded to stereo, thus, all the sonic properties of the sound are transformed and retained accordingly.
ROTATION can be quickly turned on and off by clicking on the Toggle button (in blue), however, as soon as the user modifies any of the rotation sliders, Rotation will automatically turn on.
Three sliders (in yellow) offer the user the option to rotate the signal in three axes:
Z-axis (left), is a rotation as if your head was moving from left to right.
X-axis (middle) is a rotation as if your head was looking up/down
Y-axis (right) is a rotation as if your head was moving diagonally over the Y-axis.
The visualiser helps the user see the resulting sound after it’s being rotated, this can be useful keep a visual track of where the sound is coming from.
What is true panning?
‘True Panning’ is a concept that came to us to differentiate ambisonics rotation from the traditional stereo panning. When panning in stereo, the user is simply sending one channel to another so the sound is simply moving to that direction the hard way - the sound remains static and there can be problems in the acoustics if each of the channels contains phase differences.
‘True Panning’ rotation grabs the three-dimensional signal and rotates it around the person’s head, transforming the way the sound behaves in the same immersive mix. As an example, a piano’s leftmost key and a rightmost key shouldn’t sound in the same spot if the piano is hard-panned to the left, when you place a piano to your left, the leftmost and rightmost keys still contain a stereo image as the sound arrives at your head at different times and with different reflections. With ambisonics, because all the three-dimensional information of the recording is retained in the signal, the sonic results are just like in a real-life environment.
Rotation can be applied in three directions: When you rotate your head over the Z axis (i.e. you look left/right), the X axis (up-down) or the Y axis (diagonally). In other words, you could place a piano on top of your head - sonically speaking :)
‘ab Decoder HOA’
The ‘ab Decoder HOA’ is a plugin that can be inserted in any 1st through 7th order Ambisonics chain* to be able to decode a 1st through 7th Order Ambisonics signal into different speaker arrays.
Compatibility:
Input:
This plugin should always receive a 1st through 7th Order Ambisonics Signal. Depending on your DAW, your track’s properties will be different, please refer to your DAW’s section of this guide.
Output:
The plugin’s output depends on the selected (or suggested) decoder’s settings. Make sure your studio setup and your master bus matches the amount of speakers channels.
The Decoder:
‘ab Decoder HOA’ contains a Higher Order Ambisonics Rotator as well as Input and Output meters.
Below the meters, you can select which Ambisonics Order will be decoded (equal or lower to the input). So for example, if the input is 3OA but you wish to decode only at 1OA level, you can select 1OA.
By leaving in Auto, ‘ab Decoder HOA’ will select the most convenient depending on your Speakers Array selection.
As soon as it is loaded, ‘ab Decoder HOA’ will automatically suggest an output array configuration based on the DAW setup, as the user changed the Output’s width, ‘ab Decoder’ will rearrange the Decoding arrays to try and fit the new width. So in other words, as soon as the plugin is loaded, there’s nothing that needs to be done to start working.
The Decoding output can manually be changed by clicking on the Output configuration menu and selecting the desired speaker array.
When decoding audio, the sound source of each speaker group can be modified by making the signal narrower or wider or manipulating the elevation of the sound source with the available knobs.
The sound sources locations are always visible in the visualiser, that way the user can always keep track of where each speaker is located in the sonic field.
A High-Pass (HP) filter will help you filter low frequencies from each of the channel groups of the array.
A Volume Control will allow you to fine-tune the volume of each of the channel groups of the array.
A SOLO/MUTE button allows the user to monitor specific speaker groups of the decoded signal
Finally, an LFE control is available at the bottom-right of the Plugin to send some of the Low Frequency signals to the LFE channel (when available)
‘ab Decoder HOA’ was created with the word ‘ease’ as the most important goal. For this, we wrote a plugin that automatically adapts, scans and keeps the signal healthy without the need of the user intervention.
A large chunk of the development time was spent creating an automatic troubleshoot algorithm, where the plugin checks for the signal and its routing and let’s the user know if there is an issue with it.
If the steps to set up the plugin in this user guide were followed, ‘ab Decoder’ should work out-of-the-box, however, sometimes an issue might arise and for that, ‘ab Decoder HOA' will display a message with an error code.
In this page, we list all the errors that might appear and how to solve them.
(ERR 0) Input Mismatch: Are you sure your track input has 4 or more channels?
Your track doesn’t have the minimum amount of channels needed to decode an Ambisonics track: 4.
Reaper: Make sure your track has 4 or more channels (for decoding to stereo, use 4).
Nuendo/Cubase: Make sure your track is 1st Order Ambisonics or Quad.
Pro Tools | Ultimate: You shouldn’t have this problem ;)
(ERR 1) I don't think I'm receiving an Ambisonics signal. Are you sure your source has 4 or more channels?
The source you’re feeding to your decoder might not be Ambisonics, are you sure it is?
If you’re working with Audio Brewers Libraries for Kontakt, this might be because you didn’t route the library to a 4-Channel Output in Kontakt, make sure you do that.
If you are working with Audio, make sure the WAV file is Ambisonics (4-channels)
Overall, make sure before decoding happens, if you are using any plugin, it supports multichannel audio, if you use a plugin that only supports stereo audio, it might mess with the signal, so your track’s inserts should look like this:
For Audio Tracks: Multichannel Plugins > Decoder > Stereo (or your configuration) plugins.
For Instrument Tracks: Kontakt > Multichannel Plugins > Decoder > Stereo (or your configuration) plugins.
(ERR 2) Not enough channels, make sure your track has 4 channels or enable 'Decode' to the selected amount channels
Make sure your track has 4 or more channels, the plugin is not detecting a track wide enough to carry an Ambisonics signal.
Reaper: Increase the amount of channels of the track
Nuendo/Cubase: Your track must be at least Quad/1st Order Ambisonics. Not Stereo
Pro Tools | Ultimate: You shouldn’t have this problem ;)
(ERR 3) Your track doesn't have enough Output channels. Make sure you make it wider or 'Decode' to less channels.
You’re trying to decode to more channels than your track’s. For example, you’re trying to decode to 7.1 in a 5.1 channels, so there are two channels with nowhere to go :(
Reaper: Make sure you decode to less channels to fit your track or increase the track’s width to accomodate more channels.
Nuendo/Cubase: Make sure your output has more channels or decode to less channels, try always to match your main bus’ output (Stereo > Stereo, or Surround 5.1 > Surround 5.1)
Pro Tools | Ultimate: Make sure you are decoding to the same amount of channels or less than that of your Main Bus.
(ERR 4) I don't think I'm receiving an Ambisonics signal. Are you sure your source has 4 or more channels?
The source you’re feeding to your decoder might not be Ambisonics, are you sure it is?
If you’re working with Audio Brewers Libraries for Kontakt, this might be because you didn’t route the library to a 4-Channel Output in Kontakt, make sure you do that.
If you are working with Audio, make sure the WAV file is Ambisonics (4-channels)
Overall, make sure before decoding happens, if you are using any plugin, it supports multichannel audio, if you use a plugin that only supports stereo audio, it might mess with the signal, so your track’s inserts should look like this:
For Audio Tracks: Multichannel Plugins > Decoder > Stereo (or your configuration) plugins.
For Instrument Tracks: Kontakt > Multichannel Plugins > Decoder > Stereo (or your configuration) plugins.