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d o w n l o a d
 

 (french version)

You can download the files for the pieces in the Preludes to Space series here. These can be used for diffusions/concerts or listened to in an educational context (most are available in binaural reduction on the listen page). For longer pieces, please contact me.

I offer the following formats:

1. The Nodal-3D space files on 64 channels constitute the most faithful representation of the allophonic composition format as I practice it in the Acousmonef. They can be adapted for all "true 3D" systems, that is, those based on a multilayer mesh in the three dimensions of space. This mesh can be linear matrix, like 4DSound, or irregular as in some large acousmoniums, without any significant loss of spatiality. Obviously, the more diffusion points there are, the better... We can consider around thirty channels to be a minimum value for correctly representing layering in three dimensions.

2. For the majority of acousmoniums and "immersive" devices, I propose surface transcriptions in Nodal-61 format. They can be rendered with maximum quality for systems based on a horizontal mesh containing at least twenty broadband points.

3. Specifically for domes, I have caried out the reduction of the original 80 nodes omniphonic space to 56 channels spherical space, with simulation of distance for the original peripheral points. This transcription was then encoded in 7th order (or higher) ambisonics. Here too, around thirty points/speakers is a good value (starting at ground level), even though the process can handle greater reductions.

4. I can also send the settings or optimized transcription files for any device (including, under certain conditions, for octophonic circles), the choice of compatible components depending directly on its characteristics (see examples).

All files are in Wavepack lossless compression format, 48 kHz, 24-bit. They are directly playable in Reaper.
Except for the ambisonic encoded files, their levels conform to the K-System in K-20. There is no dedicated low-frequency channel; the signals sent to the subwoofer(s) must be obtained using the Bass Management technique (see notes at the bottom of the page).
The plugins indicated for making the adaptations are free, but of course, everyone is free to use others ;-)

Download:
- Reaper for Linux, Mac, and Windows (unlimited trial version)
- the plugin GRM-Tools SpaceMaster for Windows and macOS (Intel / Rosetta. If it doesn't work on the Mac it means that you will have to download it from Linux or Windows).
- the Acousmodules SimpleTest 64 plugin for Windows and Mac (it's not essential but very useful for making adjustments and calibration)
- K-20 test file

The following mini-tutorials assume that Reaper and the audio interface are already configured and set to send the required number of channels to the speaker device, and that the intensity levels have been calibrated.

1. The files in Nodal-3D 64 channels

The Preludes to Space series currently comprises around fifty pieces, all available in this format. I have selected here those for which the "multi-layered 3D" space is most essential, particularly due to the point density required both inside and at ground level. Contact me for others.

GRM-Tools SpaceMaster plugin
Although it is a bit dated and its operation on macOS is limited to Intel processors or the use of Rosetta 2, it is perfectly suited for converting every kind of spaces with up to 64 channels. Its plugin functionality allows it to be used directly on audio objects, which can be very useful for playing multiple pieces created in different formats.

- Place the 64 channels file on a Reaper track: it will automatically configure the track to the required number of channels.
- Insert the SpaceMaster plugin onto the track (or object) and define the speaker layout corresponding to the sound system in the Layout Editor.
- Import the "Nodal-64-Cube" layout into the same window.

- Back in the main plugin interface in Calibration mode, select the layout you defined for the speaker device.
- Switch to Master mode and select the "Nodal-64-Cube" layout in "Init sources".

- Adjust the Spread parameter to around 25%
- Note: It is not necessary for the spatial representation to be exact, i.e., conforming to the actual distances between the speaker points, it is preferable that it be adjusted so as to cover the entire surface of the plugin and that the points that constitute it are as equidistant as possible.
 

2. N-61 files for acousmoniums and other enveloping spaces

For renderings with the GRM-Tools SpaceMaster plugin, the procedure is exactly the same as before, you just need to replace "Nodal-64-Cube" with "Nodal-61".

3. High-order ambisonic files for domes

Ambisonic spatial representation is particularly well-suited to devices physically based on a sphere, such as domes, but it can also be used for other peripheral (single-layer) spatial arrangements, such as variants of cinema formats, by applying the necessary distance compensations (many "domes" are actually closer to cubes).
One drawback is that the double processing applied during encoding and decoding introduces a certain loss of precision and spatial depth, which is all the more significant as the encoding order decreases. Tenth order (121 encoding channels) allows for accurate reproduction of the original format's resolution, but the gain compared to seventh order (64 encoding channels) is currently insignificant for most modern loudspeaker devices. Therefore, I am only presenting the seventh-order encoded versions here, knowing that I can provide tenth-order versions upon request.
Reminder: depending on the number of broadcast channels available, it is easy to reduce the order value for playback by simply ignoring the higher coding channels.
In all cases, it is strongly recommended that the lowest elevation level be at ground level.
And if you have the option, you can also consider increasing the size of your dome to take advantage of multi-layer decoding ;-) 

Sparta AmbiDec plugin
- Place the 64 or 121 channel file on a Reaper track; the track will automatically be configured with the required number of channels.
- Insert the Sparta AmbiDec plugin on the track and enter the angular values ​​of the speaker points corresponding to the sound system (note: for 7th order, the IEM AllRADecoder plugin is also perfect...).

- If the center distance of all speakers is not identical, insert the IEM Distance Compensator plugin after the decoding plugin and enter the center distance values for each speaker.

- Adjust the track gain according to the information provided in the footnote.

Download:
- Sparta and IEMplugins for Linux, Mac, and Windows
- The K-20 reference file encoded in HOA in the same way as the parts (see footnote)

4. specific adaptations

For loudspeaker systems that don't fall into the two previous categories, or if you lack the resources to perform the adaptations yourself, you can provide me with the precise specifications of your sound system so that I can handle them myself. This imposes a certain rigidity on the output format— it can only be played on that specific system — but ensures that it is optimized, at least in terms of its artistic quality.
The result of this conversion can be either an audio file playable directly in Reaper or a preset file for the TransSpace 80 plugin. The latter solution can be more flexible because it doesn't require sending new audio files if the system is modified, as playback always uses the original 80-channel files.
In both cases, you need to send me the precise placement of the speaker points as well as the corresponding numbers for the audio interface output channels as they appear in Reaper (important!). I recommend using the VisualSpacer 80 plugin for this (see examples below).

TransSpace 80 plugin
Unlike spatialization software such as SpatGris, the conversion between the two formats here is not automatic. It requires some familiarity and experience, and, for more complex cases, necessitates making choices based on knowledge of the work and what you want to achieve... and that's precisely what makes it so interesting (see the videos https://youtu.be/-h-NLFMnY1g and https://youtu.be/tIScN4DMqHg).
If you choose this solution:
- You provide me with the setup: the speaker positions and channel numbers (if possible, using the VisualSpacer plugin)
- I will then send you the vst.preset file for TransSpace
- On the track where the 80-channel room file is located, you insert the TransSpace 80 plugin and import the preset file that was sent to you. That's all! ;-)

Download:
- VisualSpacer 80 VST3 plugin for easily communicating the speaker device's placement, for WIndows and Mac, and its mini-manual
- TransSpace 80 VST3 plugin for WIndows and Mac, and its mini-manual (note for Mac)

Note about level calibration

All pieces are set up with a listening level calibrated according to the K-System principle in K-20: a digital reference level (pink noise at -20 dB RMS) should theoretically correspond to the listening point(s) at 83 dB-SPL (C/Slow) for each channel.
In reality, this value obviously needs to be adjusted according to the number of channels, the room's dimensions and acoustics, not to mention personal preferences, but it is nevertheless important to try to maintain this equivalence as a starting point, even if it needs to be adjusted later.
The Loudness R-128 measurement and normalization can be used as a complement or replacement in the case of ambisonics, but it is not sufficient on its own because it does not reflect the sometimes significant differences in dynamics between rooms, and obviously does not take into account the equipment and its settings, nor the room itself, and therefore the actual listening level.

Using the K-20 test file:
- Place it on a track; both the track and the master should be set to "0dB".
- Configure a sound level meter to "C curve / Slow".
- Adjust the amplification level so that the sound level meter displays approximately 83 dB-SPL for each channel at the intended listening distance.
- Repeat for each output channel/speaker.
Or, more simply:
- Insert the SimpleTest plugin on the Master, set to 0dB (the plugin's gain setting should be -12dB Peak, which is its default value).
- Play each channel in turn and adjust the amplifier gains so that the sound level meter displays the same reading as before.

Bass Management

One or more dedicated low-frequency speakers not only complement the spectrum produced by the "normal" speakers but also contribute to the overall homogenization of the system. The Acousmodules SimpleBass plugins make it easy to:
- select the crossover frequency for each output channel
- choose the crossover filter curve
- adjust and send the low-frequency signal to one to four subwoofers independently
- apply a low-cut filter to all channels corresponding to the crossover frequency
- adjust the send gain to the four subwoofers
- choose the send channel for the four subwoofers

Download the SimpleBass 36 and SimpleBass 64 plugins for Windows and Mac, and place them at the end of your signal chain on the Master or MonitoringFX module in Reaper.

* Note regarding downloading Acousmodules plugins for Mac: Due to Apple's protection policy, files downloaded from macOS will not run on the latest versions of the OS because they are not notarized. One solution is to download them from Windows or Linux and then transfer them to macOS. Another solution is to temporarily disable Gatekeeper with Sentinel.