# FDN64Reverb

FDN64Reverb is a reverb equipped with a feedback delay network (FDN). However, the size of feedback matrix is 64.

- Download FDN64Reverb 0.1.19 `full` - VST 3 (github.com)
- Download FDN64Reverb 0.1.19 `macOS` - VST 3 (github.com)
- Download Presets (github.com)

`full` package contains following builds.

- Windows (x86_64)
- Linux (x86_64)
- macOS (Universal 2)

Linux build is built on Ubuntu 24.04. If you are using distribution other than Ubuntu 24.04, plugin will not likely to run. In this case, please take a look at build instruction.

`macOS` package is recommended for macOS user. I can’t purchase Apple Developer Program, therefore installation requires a workaround to bypass Gatekeeper. Details of workaround are written in Installation -> macOS Specific section.

## Contact

Feel free to contact me on GitHub repository or `ryukau@gmail.com.`

You can fund the development through paypal.me/ryukau.

## Installation

### Plugin

Move `*.vst3` directory to:

- `/Program Files/Common Files/VST3/` for Windows.
- `$HOME/.vst3/` for Linux.
- `/Users/$USERNAME/Library/Audio/Plug-ins/VST3/` for macOS.

DAW may provides additional VST3 directory. For more information, please refer to the manual of the DAW.

### Presets

Notice: Some plugins don’t have presets provided by Uhhyou Plugins.

Presets are included in the plugin package linked at the top of this page. To install presets, follow the steps below.

1. Download plugin from a link at the top of this page.
2. Extract downloaded zip file.
3. Open `presets` directory placed in extracted package.
4. Move `Uhhyou` directory into an OS specific preset directory (see below).

Below is a list of preset directories for each OS.

- Windows : `/Users/$USERNAME/Documents/VST3 Presets`
- Linux : `$HOME/.vst3/presets`
- macOS : `/Users/$USERNAME/Library/Audio/Presets`

Preset directory name must be the same as the plugin. If preset directory does not exist, create it.

- Preset Locations - VST 3 Developer Portal

### Windows Specific

If DAW doesn’t recognize the plugin, try installing C++ redistributable (`vc_redist.x64.exe`). Installer can be found in the link below.

- Latest supported Visual C++ Redistributable downloads | Microsoft Learn

### Linux Specific

On Ubuntu 24.04, those packages are required.

    sudo apt install libxcb-cursor0  libxkbcommon-x11-0

If DAW doesn’t recognize the plugin, take a look at `Package Requirements` section of the link below and make sure all the VST3 related package is installed.

- VSTGUI: Setup

REAPER on Linux may not recognize the plugin. A workaround is to delete a file `~/.config/REAPER/reaper-vstplugins64.ini` and restart REAPER.

### macOS Specific

Important: `full` package is not confirmed working. When using `full`, try removing following files.

- `Contents/Resources/Documentation`
- `Contents/x86_64-linux`
- `Contents/x86_64-win`

`macOS` package doesn’t contain above files. Also, all packages are in “ad-hoc signing” state set by `codesign` command.

#### Remove Quarantine

When trying to run plugin first time, following message may appear on macOS.

    <PluginName>.vst3 is damaged and can't be opened. You should move it to the Trash.

In this case, open terminal and try running one or both of following command to unzipped `.vst3` directory. Replace `/path/to/PluginName.vst3` according to your install location.

    xattr -rd com.apple.quarantine /path/to/PluginName.vst3
    xattr -rc /path/to/PluginName.vst3

#### Bypass Gatekeeper

Plugin may be considered as unsigned/un-notarized application. In this case, open System Preferences, go to Security & Privacy → General, then click the Open Anyway button. The offcial Apple help page linked below has screenshots for the procedure. See “If you want to open an app that hasn’t been notarized or is from an unidentified developer” section.

- Safely open apps on your Mac - Apple Support

If the plugin is still not working, try changing install location to `/Library/Audio/Plug-ins/VST3/` or `/Users/$USERNAME/Library/Audio/Plug-ins/VST3/` whichever still haven’t tried.

If all the above methods do not work, try following the steps below.

1. Open terminal and run `sudo spctl --master-disable`.
2. Go to System Preferences → Security and Privacy → General → Allow apps downloaded from, then select “Anywhere”.

Beware that steps above degrades security of your system. To revert the settings, follow the steps below.

1. Go to System Preferences → Security and Privacy → General → Allow apps downloaded from, then select option to “App Store and identified developers”.
2. Open terminal and run `sudo spctl --master-enable`.

#### Applying `codesign`

Note This section may not relevant to `macOS` packages. However it’s not verified. (GitHub issue)

To use `full` package, following command might be used.

    sudo codesign --force --deep -s - /path/to/PluginName.vst3

`codesign` might not be available without installing Xcode.

#### Reference

- Safely open apps on your Mac - Apple Support
- java - “libprism_sw.dylib” cannot be opened because the developer cannot be verified. on mac JAVAFX - Stack Overflow
- How to Fix App “is damaged and can’t be opened. You should move it to the Trash” Error on Mac
- Allowing unsigned/un-notarized applications/plugins in Mac OS | Venn Audio

## GUI Style Configuration

At first time, create color config file to:

- `/Users/USERNAME/AppData/Roaming/UhhyouPlugins/style/style.json` on Windows.
- `$XDG_CONFIG_HOME/UhhyouPlugins/style/style.json` on Linux.
  - If `$XDG_CONFIG_HOME` is empty, make `$HOME/.config/UhhyouPlugins/style/style.json`.
- `/Users/$USERNAME/Library/Preferences/UhhyouPlugins/style/style.json` on macOS.

`style.json` will be loaded for each time a plugin window opens.

Several color themes are available on the link below. To use, copy the text to `style.json`.

- VSTPlugins/package/style/themes at master · ryukau/VSTPlugins

Below is an example of `style.json`.

    {
      "guiScale"          : 1          ,
      "fontFamily"        : "Tinos"    ,
      "fontBold"          : true       ,
      "fontItalic"        : true       ,
      "foreground"        : "#000000"  ,
      "foregroundButtonOn": "#000000"  ,
      "foregroundInactive": "#8a8a8a"  ,
      "background"        : "#ffffff"  ,
      "boxBackground"     : "#ffffff"  ,
      "border"            : "#000000"  ,
      "borderCheckbox"    : "#000000"  ,
      "borderLabel"       : "#000000"  ,
      "unfocused"         : "#dddddd"  ,
      "highlightMain"     : "#0ba4f1"  ,
      "highlightAccent"   : "#13c136"  ,
      "highlightButton"   : "#fcc04f"  ,
      "highlightWarning"  : "#fc8080"  ,
      "overlay"           : "#00000088",
      "overlayHighlight"  : "#00ff0033"
    }

### GUI Scale

- `guiScale`: GUI scaling. For example, `0.75` is 75%, and `2.0` is 200%.

The minimum of `guiScale` is `0.01`. The maximum is practically non-existent (the max value of 64-bit float).

Notice: If `guiScale` is too large, DAW may place the “close” button on the plugin window out of screen, making it unclickable.

### Font Options

Following is a list of font options.

- `fontFamily`: Font family name.
- `fontBold`: Enable bold style when `true`, disable when `false`.
- `fontItalic`: Enable italic style when `true`, disable when `false`.

System font can be used as `fontFamily`. To use different fonts for different plugins, place `*.ttf` file into custom font path: `*.vst3/Contents/Resources/Fonts`.

Notice: If the combination of `fontFamily`, `fontBold`, `fontItalic` does not exist in custom font path, default font of VSTGUI is used.

If `fontFamily` is set to empty string `""`, then `"Tinos"` is used as fallback. If the length is greater than 1 and the font family name doesn’t exist, default font of VSTGUI is used.

Styles other than bold, italic or bold-italic are not supported by VSTGUI. For example, “Thin”, “Light”, “Medium”, and “Black” weights cannot be used.

### Color Options

Hex color codes are used.

- 6 digit color is RGB.
- 8 digit color is RGBA.

First letter `#` is conventional. Plugins ignore the first letter of color code, thus `?102938`, `\n11335577` are valid.

Do not use characters outside of `0-9a-f` for color value.

Following is a list of color options. If an option is missing, default color will be used.

- `foreground`: Text color.
- `foregroundButtonOn`: Text color of active toggle button. Recommend to use the same value of `foreground` or `boxBackground`.
- `foregroundInactive`: Text color of inactive components. Currently, only used for TabView.
- `background`: Background color.
- `boxBackground`: Background color of inside of box shaped components (Barbox, Button, Checkbox, OptionMenu, TextKnob, VSlider).
- `border`: Border color of box shaped components.
- `borderCheckbox`: Border color of CheckBox.
- `borderLabel`: Line color of parameter section label.
- `unfocused`: Color to fill unfocused components. Currently, only used for knobs.
- `highlightMain`: Color to indicate focus is on a component. Highlight colors are also used for value of slider components (BarBox and VSlider).
- `highlightAccent`: Same as `highlightMain`. Used for cosmetics.
- `highlightButton`: Color to indicate focus is on a button.
- `highlightWarning`: Same as `highlightMain`, but only used for parameters which requires extra caution.
- `overlay`: Overlay color. Used to overlay texts and indicators.
- `overlayHighlight`: Overlay color to highlight current focus.

## Controls

`Right Click` on the controls pops up a context menu provided by DAW.

Knob and slider provides following controls:

- `Ctrl` + `Left Click`: Reset value.
- `Shift` + `Left Drag`: Fine adjustment.
- `Middle Click` : Rotate through minimum, default and maximum value.
- `Shift` + `Middle Click` : Take floor of current value.
  - Note: For decibel (`dB`) parameters, floor is applied after the value is converted to amplitude.

Control with many blue vertical bars (BarBox) have some keyboard shortcuts. Shortcuts are enabled after left clicking BarBox and mouse cursor is on the inside of BarBox.

Input | Control
--- | ---
`Left Drag` | Change Value
`Shift` + `Left Drag` | Change Value (Snapped)
`Ctrl` + `Left Drag` | Reset to Default
`Ctrl` + `Shift` + `Left Drag` | Change Value (Skip Between Frames)
`Middle Drag` | Draw Line
`Shift` + `Middle Drag` | Edit One Bar
`Ctrl` + `Middle Drag` | Reset to Default
`Ctrl` + `Shift` + `Middle Drag` | Toggle Lock
`a` | Alternate Sign
`d` | Reset Everything to Default
`D` | Toggle Min/Mid/Max
`e` | Emphasize Low
`E` | Emphasize High
`f` | Low-pass Filter
`F` | High-pass Filter
`i` | Invert Value (Preserve minimum)
`I` | Invert Value (Minimum to 0)
`l` | Toggle Lock under Mouse Cursor
`L` | Toggle Lock for All
`n` | Normalize (Preserve minimum)
`N` | Normalize (Minimum to 0)
`p` | Permute
`r` | Randomize
`R` | Sparse Randomize
`s` | Sort Descending Order
`S` | Sort Ascending Order
`t` | Subtle Randomize (Random walk)
`T` | Subtle Randomize (Converge to 0)
`z` | Undo
`Z` | Redo
`,` (Comma) | Rotate Back
`.` (Period) | Rotate Forward
`1` | Decrease
`2`-`4` | Decrease 2n-4n
`5`-`9` | Decimate by holding 2n-5n

Snapping is not available for all BarBox. If you’d like to have snapping for certain BarBox, feel free to open issue to GitHub repository.

Edit One Bar with `Shift` + `Right Drag` holds a bar under the cursor when mouse right button is pressed. Then only changes that one bar while holding down mouse right button.

Toggle Lock with `Ctrl` + `Shift` + `Right Drag` behaves as line edit. When right mouse button (RMB) is pressed, it holds the opposite state of the bar below mouse cursor, then use the state for the rest of bars. For example, if RMB is pressed on a locked bar, dragging unlocks bars while holding down RMB.

Some BarBox has scroll bar to zoom in. Scroll bar has handles on left end and right end. To control zoom, use `Left Drag` on one of the handle. Scroll bar also has following controls:

- `Right Click` : Reset zoom.
- `Mouse Wheel` : Zoom in/out.

## Caution

Setting `Feedback` to 1 and `Highpass Cutoff` to 0 might adds massive direct current depending on input signal.

## Block Diagram

If the image is small, use `Ctrl` + `Mouse Wheel` or “View Image” on right click menu to scale.

Diagram only shows overview. It’s not exact implementation.

## Parameters

Delay Time [s]

  Delay times in seconds. Below is the equation to calculate the total of delay time.

      delayTime = (Time Multi.) * (Delay Time) + (Time LFO Amount) * random().

  Note that maximum delay time do not exceed 1 second. This means that if both `Delay Time` and `Time LFO Amount` are set to 1, then LFO stop working.

Time LFO Amount [s]

  Amounts of LFO modulation to delay times.

  When `Interp. Rate` exceeds 1.0, LFO modulations start adding noticeable noise. To get smooth output, recommend to set `Interp. Rate` under 0.25.

Lowpass Cutoff [Hz]

  Cutoff frequencies of lowpass filters that are applied to delay outputs.

Highpass Cutoff [Hz]

  Cutoff frequencies of highpass filters that are applied to delay outputs.

  Note that setting `Feedback` to 1 and `Highpass Cutoff` to 0 might adds massive direct current depending on input signal.

### Delay

Time Multi.

  A multiplier to `Delay Time`. Useful to change all the delay time at once.

Feedback

  Feedback amount of FDN. In other words, `Feedback` is a scalar that multiplies feedback matrix.

  When `Feedback` is close to 1.0, it lengthen the reverb time. When set to exactly 1.0, the reverb stop to decay. In this case, `Gate` can be used to shut down the reverb.

Interp. Rate

  Rate limiting value of delay time interpolation. For example, when `Interp. Rate` is set to 0.1, changing delay time from 0 to 1 samples requires 10 samples of interpolation time.

Gate [dB]

  Threshold of gate.

  When input amplitude is less than the value of `Gate` for a while, the gate modulates `Stereo Cross` to make output amplitude to 0.

  Gate is intended to use with rotation. Release time is approximately 5 ms.

Matrix

  Type of feedback matrix. Note that changing this parameter may cause pop nosie.

  Abbreviation | Full Name | Additional Infomation | Quality
  --- | --- | --- | ---
  Ortho. | Orthogonal |  | Good
  S. Ortho. | Special orthogonal |  | Good
  Circ. Ortho. | Circulant |  | OK
  Circ. 4 | Circulant | 4 non-zero elements per row | SFX
  Circ. 8 | Circulant | 8 non-zero elements per row | SFX
  Circ. 16 | Circulant | 16 non-zero elements per row | SFX
  Circ. 32 | Circulant | 32 non-zero elements per row | SFX
  Upper Tri. + | Upper triangular | Range of randomization is `[0, 1]` | Bad
  Upper Tri. - | Upper triangular | Range of randomization is `[-1, 0]` | Bad
  Lower Tri. + | Lower triangular | Range of randomization is `[0, 1]` | Bad
  Lower Tri. - | Lower triangular | Range of randomization is `[-1, 0]` | Bad
  Schroeder + | Schroeder reverb | Range of randomization is `[0, 1]` | Bad
  Schroeder - | Schroeder reverb | Range of randomization is `[-1, 0]` | Bad
  Absorbent + | Absorbent allpass | Range of randomization is `[0, 1]` | OK
  Absorbent - | Absorbent allpass | Range of randomization is `[-1, 0]` | OK
  Hadamard | Hadamard | No randomization | Good
  Conference | Conference | No randomization | Good

  Quality is rough indication. Bad means it frequently adds metallic tones to output. Good means almost no metallic tone. OK is in between good and bad. SFX means they sound strange as a reverb. Bad matrices can be used to add more effects with rotation.

Seed

  Seed value for randomization of feedback matrix. Note that changing this parameter may cause pop nosie.

Change Matrix

  A button to randomize feedback matrix. Pressing `Change Matrix` also changes the value of `Seed`. Note that changing this parameter may cause pop nosie.

### Mix

Dry [dB]

  A gain applied to input signal which bypasses FDN.

Wet [dB]

  FDN output gain.

Stereo Cross

  Stereo crossing feedback amount between left and right FDNs. Setting `Stereo Cross` to 1.0 stops input to prevent blow up.

### Rotation

Speed [Hz]

  Rotation speed of FDN input gains.

Offset

  Initial phase of the waveform to rotate input gains.

  `Offset` can be used to change the sound when `Speed` is 0, but `Skew` is greater than 0. Feedback matrix affects the character of output.

Skew

  Changes the waveform used to rotate input gains. Note that when `Skew` is set to 0, `Speed` and `Offset` stop working.

  Below is a plot of relation between `Skew` and rotation waveform.

## Change Log

- 0.1.19
  - Fixed a bug that plugin to show up with incorrect window size (likely 512x512 pixels) at initialization.
  - Changed internals to speed up.
- 0.1.18
  - Added GUI scaling.
  - Fixed a bug on BarBox that the “ascending sort” shortcut was disabled.
  - Updated the Linux patch for VSTGUI4.
- 0.1.17
  - Fixed GUI on Linux.
- 0.1.16
  - Changed to include presets in plugin zip package.
  - Fixed a bug that invalid `style.json` crashes plugin.
- 0.1.15
  - Changed default style color of `foregroundInactive`.
  - Fixed performance drop caused by subnormal floating point numbers.
- 0.1.14
  - Added note event input to control delay times.
- 0.1.13
  - Fixed crash on Renoise. Previous code was trying to access freed memory of GUI widgets, and it was causing the crash.
- 0.1.12
  - Fixed stuttering on Audacity where `processContext` is `nullptr`.
- 0.1.11
  - Updated splash screen text.
- 0.1.10
  - Added decimation by holding shortcut to BarBox. Shortcut is `5`-`9`.
  - Added floor shortcut to number sliders. Shortcut is `Shift` + `Middle Click`.
  - Fixed to reset `Rotation` counter.
- 0.1.9
  - Added to `virtual` to destructor of common components. This may prevent some cause of crash or memory leak.
- 0.1.8
  - Updated VST 3 SDK to version 3.7.6. This also fixes the crash when opening multiple GUI of same plugin on Linux.
  - Change BarBox to only send modified parameter values to host. This prevents to overwrite unchanged parameter automation on the same BarBox.
- 0.1.7
  - Changed BarBox to get focus on mouse down, and release focus on mouse exit.
- 0.1.6
  - Removed dependency to x86_64 specific SIMD instructions.
- 0.1.5
  - Fixed crash on Linux.
  - Fixed BarBox to receive shift key.
- 0.1.4
  - Fixed a bug that `Interp. Rate` is shared between all FDN64Reverb instances.
- 0.1.3
  - Fixed the condition of acceptable channel count. This is a fix for unintentional muting on sidechain in REAPER.
- 0.1.2
  - Added custom font options for `style.json`.
- 0.1.1
  - Updated VSTGUI from 4.10 to 4.11.
- 0.1.0
  - Initial release.

## Old Versions

- FDN64Reverb 0.1.18 - VST 3 (github.com)
- FDN64Reverb 0.1.17 - VST 3 (github.com)
- FDN64Reverb 0.1.16 - VST 3 (github.com)
- FDN64Reverb 0.1.15 - VST 3 (github.com)
- FDN64Reverb 0.1.14 - VST 3 (github.com)
- FDN64Reverb 0.1.13 - VST 3 (github.com)
- FDN64Reverb 0.1.12 - VST 3 (github.com)
- FDN64Reverb 0.1.11 - VST 3 (github.com)
- FDN64Reverb 0.1.10 - VST 3 (github.com)
- FDN64Reverb 0.1.9 - VST 3 (github.com)
- FDN64Reverb 0.1.8 - VST 3 (github.com)
- FDN64Reverb 0.1.7 - VST 3 (github.com)
- FDN64Reverb 0.1.6 - VST 3 (github.com)
- FDN64Reverb 0.1.5 - VST 3 (github.com)
- FDN64Reverb 0.1.4 - VST 3 (github.com)
- FDN64Reverb 0.1.3 - VST 3 (github.com)
- FDN64Reverb 0.1.2 - VST 3 (github.com)
- FDN64Reverb 0.1.0 - VST 3 (github.com)

## License

FDN64Reverb is licensed under GPLv3. Complete licenses are linked below.

- https://github.com/ryukau/VSTPlugins/tree/master/License

If the link above doesn’t work, please send email to `ryukau@gmail.com`.

### About VST

VST is a trademark of Steinberg Media Technologies GmbH, registered in Europe and other countries.