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Update: 2020-08-18

Table of Contents


L4Reverb is an extended version of LatticeReverb. This time, lattice structure has 4 * 4 * 4 * 4 = 256 sections per channel.

If L4Reverb is too heavy for your machine, L3Reverb is also available. L3Reverb is a trimmed down version of L4Reverb. The lattice structure has 3 * 3 * 3 * 5 = 135 sections per channel.

L4Reverb and L3Reverb requires CPU which supports AVX or later SIMD instructions.

The package includes following builds:

macOS build isn’t tested because I don’t have Mac. If you found a bug, please file a issue to GitHub repository or send email to

Linux build is built on Ubuntu 18.0.4 and tested on Bitwig and Reaper. If you are using distribution other than Ubuntu 18.04, plugin will not likely run. In this case, please take a look at build instruction.



Place *.vst3 directory to:

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


Extract preset zip, then place preset directory to the OS specific path:

Preset directory name must be the same as the plugin. Make Uhhyou directory if it does not exist.

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.

Linux Specific

On Ubuntu 18.0.4, 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.

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

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 following command to unzipped .vst3 directory.

xattr -rc /path/to/PluginName.vst3

Plugin may be considered as unsigned/un-notarized application. In this case, 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.


Color Configuration

At first time, create color config file to:

Below is a example of style.json.

  "fontPath": "",
  "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"

Hex color codes are used.

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.


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

Knob and slider can do:

There is an additional control for number sliders used for Octave, Seed etc.

Control with many blue vertical bars (BarBox) have some keyboard shortcuts. LFO Wave on Main tab and Gain, Width, Pitch, Phase on Wavetable tab are using BarBox. Shortcuts are enabled after left clicking BarBox and mouse cursor is on the inside of BarBox. Cheat sheet is available on Infomation tab.

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)
Right Drag Draw Line
Shift + Right Drag Edit One Bar
Ctrl + Right Drag Reset to Default
Ctrl + Shift + Right 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
2-9 Decrease 2n-9n

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:


Output may change with different sample rate or buffer size.

Output may blow up when both Cross and Spread are not 0.

Output may become loud when offset of *Feed is not 0, and modulation is enabled.

Output may become loud when following steps are performed.

  1. Set some of the OuterFeed or InnerFeed to close to minimum or maximum.
  2. Input signals.
  3. Change the value of OuterFeed or InnerFeed which was set at step 1.

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.



Delay time of all-pass filter.


Feedback and feedforward gain of all-pass filters nested inside of lattice structure.


Feedback and feedforward gain of lattice structure at lowest layer.


Feedback and feedforward gain of lattice structure at 2nd lowest layer.


Feedback and feedforward gain of lattice structure at 3rd lowest layer.


Feedback and feedforward gain of lattice structure at top layer.

Tip: Setting all of the *Feed values to negative makes output more wet by blurring input signal. Especially recommend to fine tuning D4Feed.


Multiplier for Time and *Feed. Useful to shorten or lengthen reverb.

Base values are used in both left and right channel. Base value determines the character of reverb.

Offset values are maximum ratio between left and right channel. Amount of ratio is randomized. Changing Offset spreads reverb to stereo.

if (Offset >= 0) {
  valueL = Base
  valueR = Base * (1 - Offset)
else {
  valueL = Base * (1 + Offset)
  valueR = Base

When Modulation is checked, Offset values will be randomized for each buffer. Smooth can be used to change the character of modulation.


Pressing Panic! button stops reverb output by setting multiplier of Time and *Feed to 0.

Useful to stop sounds in case of blow up.



Gain of input signal.


Gain of reverb signal.



Feedback amount from an output of lattice structure to the lattice structure on another channel. If the value is 0, signal from other channel will not be mixed.


Mid-side (M-S) signal ratio.

Following equations are used to calculate mid-side signal.

mid  = left + right
side = left - right

left  = mid - Spread * (mid - side)
right = mid - Spread * (mid + side)



Seed value of random number sequence.


Transition time to change parameter value to current one. Unit is in second.

Change Log



Old Versions


L4Reverb and L3Reverb is licensed under GPLv3. Complete licenses are linked below.

If the link above doesn’t work, please send email to

About VST

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