Welcome to modouVerb

modouVerb is a space-based, high-density reverb from modou dsp.

Most reverbs give you a set of knobs such as size, decay, diffusion and mix, and leave you to imagine the room. modouVerb works the other way round. You choose a space that exists as real 3D geometry. You place a sound source and a microphone inside it, and you decide how far apart they stand. The engine then renders what that microphone hears at that spot, facing that way, in that room.

modouVerb comes in three editions built on one engine:

• modouVerb Standard is the full mono and stereo reverb.
• modouVerb Immersive is the full reverb for 7.1.4 to 9.1.6 speaker beds.
• modouVerb Lite is a two-control version for musicians who just want it to sound right.

This manual covers all three. Most chapters apply to every edition. Where something is edition-specific, a label says so.

This manual describes modouVerb v1.0.6.

A reverb is heard at one particular spot in a particular room. When you stand closer to a singer, three things change at once:

• the direct sound gets louder and brighter;
• the first reflections arrive later relative to it, and in a different order;
• the reverberant tail stays roughly as loud as before.

Turn your head, and the reflections swap ears. Move the singer toward a side wall, and that wall answers first and loudest.

Classic reverbs imitate the result of these relationships with independent controls such as mix, pre-delay, size and width. You can set those controls into combinations that no real room could produce. Sometimes that is exactly what you want. But it is also why a reverb so often sounds "pasted on" instead of around the source.

modouVerb keeps the relationships and lets you control the causes:

Where is the source? Where is the microphone? Which way does it point? What room are they in?

Everything you hear follows from those answers: the level and colour of the direct sound, the timing and direction of every early reflection, the balance of early to late energy, and the image across the speakers.

The three editions share the sound and differ in scope.

Requirements: macOS 10.13 or later on Intel, macOS 11 or later on Apple Silicon, and a host that loads Audio Unit (AU), VST3 or AAX plugins. Each edition also ships as a standalone application. Run ./build_installer.sh for a signed, notarized installer package.

In the host, the plugins appear under the manufacturer modou dsp. The three editions are separate plugins with separate plugin codes. You can install them side by side and use them in the same session.

User presets are saved as .mverbpreset files in ~/Library/Audio/Presets/modou dsp/modou VERB/. Standard and Immersive share this folder.

If a host still shows an older version after an update, rescan the plugins. On macOS you can also log out and back in so the Audio Unit cache is rebuilt.

Licensing

Each edition needs a licence from modou Central before it processes audio; an unlicensed instance stays silent (a mute DSP path, not a broken one). Open the gear icon in the plugin's header (or the modou Central app) to enter a licence key and email, or to request a trial. A licence is checked against your machine's hardware ID and can be moved between machines by deactivating it first. The three editions use separate SKUs (modou0010 Standard, modou0011 Immersive, modou0012 Lite), so each is licensed on its own.

Click the gear icon at the right of the header to open the Utility panel: licence status, display settings and credits, without leaving the plugin.

• Licence: reads ACTIVATED, TRIAL or UNLICENSED, with the licensed email or the remaining trial days underneath.
• Machine ID (HWID): masked by default. Copy puts the full ID on the clipboard, for support or for activating in modou Central.
• Manage Licence in modou Central: opens modou Central (or its download page) to enter a key, start a trial, or move a licence to this machine.
• 3D Stage Hint: on by default. The first time the 3D stage appears, it briefly orbits on its own so you notice it is a real 3D view you can drag and zoom, not a flat picture. Once you know that, turn it off here.
• Window Zoom: the same zoom the window's own resize handle sets, also reachable as a menu from 100 % to 200 %.

When a sound plays in a room, the microphone (or your ear) receives three kinds of energy, one after another:

1 · Direct sound

The sound that travels in a straight line from the source to the microphone. Its level falls by 6 dB for every doubling of distance (the inverse-square law), and air absorbs its highest frequencies as the path gets longer. The direct sound tells the brain where the source is.

2 · Early reflections

Sound that bounced once, twice or three times off the walls, floor and ceiling before it reached the microphone. Each reflection has a precise arrival time, a direction and a colour, set by the path length and by the surfaces it touched. The gap between the direct sound and the first reflection is the initial time delay gap (ITDG). The ear reads the pattern of early reflections as the size and shape of the room and as the distance to the source.

3 · Late reverberant field

After many bounces, the reflections become so dense that they merge into a smooth, decaying wash with no audible direction. Its decay time T60 (the time to fall by 60 dB) depends on the room's volume and on how absorbent its surfaces are, separately at low, mid and high frequencies. In a given room the late field is nearly equally loud at every seat.

The critical distance

Because the direct sound falls with distance but the late field does not, there is one distance at which they are equally loud: the critical distance r_c. Closer than r_c, you hear mostly the source. Farther away, you hear mostly the room. In a small studio r_c is about a metre. In a large, reverberant hall it is several metres. This single fact is why "wetness" in a real room is a matter of where you stand, not of a mix control.

Almost every algorithmic reverb descends from the same family of ideas. Schroeder's comb-and-allpass networks came in the early 1960s. Moorer added early-reflection taps and in-loop filtering. From the 1990s on, the feedback delay network (FDN) became the standard: a set of delay lines whose outputs are mixed by a matrix and fed back. These are excellent tools. modouVerb itself uses a high-density FDN for its late field. But when the whole reverb is built only from delays, several limits follow.

The room is a statistic, not a place

The delay lengths are chosen to be mutually prime and "roughly room-sized". A SIZE control usually scales all of them together. Nothing in the algorithm knows where the walls are. So nothing can tell you what happens when the singer moves to the left, or when the microphone moves back.

Early reflections are a fixed tap pattern

The early part is usually a tapped delay line: a hand-made list of times and gains, sometimes one per "room type". The pattern is the same for every source and every listening position. In a real room, moving the listener changes every reflection's time, level and direction. In a tap pattern, only the global PRE-DELAY moves.

DRY/WET is not distance

A mix knob crossfades between the dry signal and a finished reverb. In a real room, moving away from the source changes several things at once:

• the direct sound drops and loses high frequencies;
• the reflections arrive closer to the direct sound in time;
• the balance of early to late energy shifts;
• the late field stays almost constant.

A mix knob does only the first of these, and without the colour change. That is why turning up the mix often sounds like "more reverb on top" rather than "further away".

Ringing, flutter and metallic colour

A network with too few echoes per second rings at its own delay lengths. Designers hide this with modulation, which smears the pitch, and with heavy input diffusion, which smears the transients. The tail then sounds smooth but generic.

Stereo is a trick, and multichannel is an upmix

Stereo width usually comes from taking two decorrelated outputs of the same network. There is no microphone that can be turned, no polar pattern, and no image. Most "surround" reverbs create extra outputs by further decorrelation or by upmixing stereo. The reflections do not come from where the walls are.

A delay-based reverb answers "how long and how dense?" very well. It cannot answer "from where, to where, and in what room?"

Convolution reverbs take the opposite approach. A real room is measured once: a loudspeaker plays a sweep, a microphone records it, and the result is the room's impulse response (IR). Convolving your audio with that IR places it in the measured room with great realism. For that one seat, convolution is the most faithful method there is. The limits come from the word one.

One source position, one mic position, frozen

An IR is valid for exactly one loudspeaker position and one microphone position. You cannot move the singer closer, move the mic back, raise it, or place the drums at the side of the stage. Libraries try to cover this with a few alternative positions (near, mid, far). Switching between them jumps, it does not move.

The measurement equipment is baked in

The IR contains more than the room:

• the frequency response and directivity of the loudspeaker used;
• the microphone model, its polar pattern and the direction it faced;
• the stereo technique (AB, XY, ORTF, Decca tree);
• the measurement noise floor and any truncation of the tail.

None of these can be changed afterwards. You cannot turn a cardioid into a figure-8, or rotate the mic by 90°.

Crossfading two IRs is not an intermediate seat

Blending the "near" and "far" IRs gives you both sets of reflections at once, at their own times: a double image with comb filtering. It is not the reflection pattern of a seat in between. Distance cannot be automated smoothly with fixed IRs.

Editing the IR is not physics

Shortening or lengthening the decay by reshaping the IR's envelope also reshapes the early reflections and bends the natural frequency-dependent decay. Pre-delay made by trimming or padding the IR moves the direct sound together with the room.

Multichannel multiplies the problem

A stereo-in, stereo-out ("true stereo") reverb already needs four IRs. For a real 7.1.4 input and output you need one IR from every input speaker to every output microphone: 12 × 12 = 144 measured responses, for one room and one arrangement. They are rarely measured, rarely consistent, and very expensive to convolve. So most immersive convolution reverbs place one or two sources in the room and upmix the rest.

An impulse response is a photograph of a room. modouVerb is the room.

modouVerb models the real physical conditions of a space — its geometry, its materials, where the source and the microphone actually stand in it — and generates the reverb from that model, rather than approximating a room with a chain of delay taps or freezing one seat into a fixed impulse response. It is a reverb built on real acoustic conditions carried as far into the virtual as they will go, which is what puts it past the fixed limits of an ordinary algorithm and of an IR. Concretely, it combines the physical parts that matter for where with a high-density network that is best at how long. Room-acoustics prediction software uses the same hybrid.

Because the reflections are computed rather than recorded, you can change what an IR cannot: move the source, move and turn the microphone, change its pattern, lengthen the decay without touching the early field, and render from a 2-channel to a 16-channel speaker layout from the same model.

Because the late field is a tuned high-density network rather than a recording, it is noise-free, can be as long as you like, reacts smoothly to every control, and is cheap: about 1–2.5 % of one CPU core for a stereo instance.

The last row is honest. If you need that exact hall, convolution is the right tool. If you need a room you can work in, where you place things, move them and automate them, modouVerb is.

Each space is a complete, independent design:

• a closed 3D polyhedron;
• a material for each face;
• an early-reflection design;
• a late-field tuning with its own delay-line lengths, diffusers, damping and modulation;
• a designed placement of the source and the microphone;
• a distance range.

None of the rooms is a box, a cylinder or a sphere. Parallel walls and simple symmetric shapes produce flutter echoes and strong room modes. Real performance spaces avoid them, and so does modouVerb.

The figures below come from the engine itself. Volume is the polyhedron's real volume. T60 is given at DECAY 1.00× for the low / mid / high bands. r_c is the critical distance computed from that volume and the mid T60. DISTANCE is the range of the source-to-mic control.

Studio

Short, natural reflections. A treated control-room-sized space. The walls are splayed so that no two are parallel, and the ceiling rises toward the back. The side walls and the absorbent ceiling take out most of the highs. The back wall is a strong diffuser (scattering 0.75), and the floor is hard. The result is a short, tight room (0.36 s) with a clear sense of walls and no flutter. Use it for "in the room" vocals, drum rooms and small ensembles, and whenever a sound needs space but not reverb.

Chamber

Warm, dense reverberation. Modelled on the classic studio echo chamber: a small, very reflective room with a pentagonal plan and a tilted ceiling. That is the traditional way to stop flutter in a hard room. The surfaces are hard plaster with little absorption, so the decay is long for the size (1.5 s mid) and heavy in the lows (1.9 s). The critical distance is only 0.6 m, so the chamber turns wet very quickly as the microphone moves back. That is the famous chamber density.

Concert Hall

Wide, balanced space. A fan-shaped hall that opens out from the stage, with a faceted rear wall and a ceiling rising toward the back. The audience area is absorbent and strongly scattering, and the rear wall is treated. This is the default space: 2.1 s mid-band decay, lower bands a little longer, highs shorter, the balance of a good concert hall. With a 5.3 m critical distance, the first metres keep the source present, and the back rows are truly distant.

Gothic Church

High ceiling, long decay. A Latin-cross plan with a nave, a transept and a faceted apse, under a gabled vault that rises to 28 m along the nave. Stone surfaces reflect almost everything. The ribbed vault scatters strongly (0.6) and the floor is smooth stone. Decay is 5.6 s in the mids and 7 s in the lows. The source stands at the altar end, and the far seat is 36 m away down the nave. Reflections from the transept arms and the vault reach the microphone from the sides and from above.

Cave

Dark, irregular reflections. A nine-sided cavern with a sloping rock roof. Rock absorbs high frequencies strongly and scatters almost everything (0.7–0.85). The early field is roughened further: image positions are jittered and each strong reflection throws extra scattered "satellite" taps. The late field uses two allpasses in every delay line. The result is dark, grainy and enveloping, with 3.4 s mid decay and highs dying early.

Tunnel

Long, strongly directional reflections. A 140 m horseshoe-section tunnel that bends by 6° halfway along, and whose ends are open: sound that reaches an end leaves. The concrete is smooth and mostly specular, so reflections run along the tube. The early field is traced to 4th order (all other rooms use 3rd), and the late field is kept narrow, as a tube sounds. The source stands inside the tunnel, and the microphone can move up to 60 m away down its length and around the bend.

Warehouse

Hard surfaces, wide space. A large trapezoidal industrial shed under a five-tooth sawtooth roof ("north-light" trusses). Each tooth has a vertical glazed riser that throws reflections back toward the source. The floor is polished concrete and almost perfectly specular. The walls are hard, and the roof glazing scatters moderately. It is big, bright-ish and slightly rough, with 3.1 s mid decay, the sound of lofts, factories and large live rooms.

Plate

High-density 2D diffusion. Not a room but a 2.0 × 1.0 m steel reverb plate. It has no geometric early reflections. Instead, sound spreads as bending waves, which travel faster at high frequencies. modouVerb reproduces this with dispersion stages inside the network and in front of it. On the Plate, DISTANCE is the distance on the plate surface between the driver and the pickups: 5 cm to 1.6 m. The decay is brightest in the mids and highs (2.4 s mid, 2.0 s high), as on a real plate. The 3D stage shows the plate from above, and the camera is fixed.

The designed placement

Every space has a designed placement: where a sensible engineer would put the source and the microphones.

• Source: on the stage, at the altar or inside the tunnel mouth, 1.35–1.8 m high.
• Microphone: moves back along a "seat path" from near the source toward the back of the room, 1.2–1.6 m high.
• Offset: the microphone sits slightly off the centre line, because perfectly centred positions in a symmetric room sound artificial.

DISTANCE moves the microphone along this path. The placement controls let you leave it.

modouVerb renders every sound as three parallel fields that meet at the microphone. The same room model drives all three.

Specular early reflections — image sources

The engine mirrors the source in every face of the polyhedron, then mirrors those images again, up to 3rd order (4th order in the Tunnel). Each candidate path is then checked for real:

• the reflection point must lie on the face, not on its infinite extension;
• no other face may block any leg of the path.

In concave rooms such as the church cross, the sawtooth roof or the cave, many mirror images are invisible from a given seat, and the engine removes them. For each surviving path:

• Time is the path length ÷ 343 m/s, measured from the direct sound.
• Level follows 1/distance, times the reflection coefficient of every face touched, separately below and above a per-space crossover of about 1 kHz.
• High frequencies are also lost to air absorption along the path.
• Direction of arrival is known exactly and goes to the microphone model.

The strongest reflections inside the space's early window (60 ms in the Studio up to 220 ms in the Church) are kept: 28 to 48 taps depending on the space. Later reflections are left to the late field.

Diffuse early reflections — "diffuse rain"

Real surfaces are rough. Part of the energy that hits a wall scatters in all directions, and the rest reflects like a mirror. The share that scatters is the surface's scattering coefficient (0 = mirror, 1 = fully diffuse). modouVerb traces this energy with rays:

• 384 rays leave the source and are followed for 5 bounces.
• At every hit, the surface's scattering share of the ray's energy is radiated toward the microphone in a Lambert (cosine) pattern, if the microphone can see that point. The remaining specular share continues along the mirror direction.
• The scattered energy is collected into 12–48 time bins per seat. Each bin keeps an energy-weighted arrival time, a direction and a low/high balance, and becomes a diffuse tap.
• Two safeguards stop a single lucky ray from becoming an audible spike: the solid angle a surface patch can cover is capped, and each patch's energy is spread over several arrival times.
• Smooth surfaces (scattering 0) produce no diffuse field.

These are the same rays the 3D stage draws. The picture and the sound come from one model.

Combining and moving the early field

The specular and diffuse taps together fade in over the first 3–8 ms after the direct sound. This comb guard keeps a very early reflection from colouring the direct sound like a comb filter.

When the source or the microphone moves, a background thread rebuilds the pattern for the new placement. That takes about 0.1–2 ms. The audio thread then crossfades to the new pattern over 40 ms, so moves and automation are smooth and click-free. When the host renders offline (bounce or export), the rebuild happens synchronously, so every placement change lands sample-exactly in the file.

Along the designed seat path the engine keeps nine pre-computed distance snapshots and interpolates between them. DISTANCE therefore moves continuously through true reflection patterns, not through a crossfade of two seats.

The late field — a high-density FDN

• 16 delay lines, lengths spread irregularly over a per-space range: 7–23 ms in the Studio, 38–135 ms in the Church, 22–150 ms in the Tunnel.
• Mixing matrix: a 2D-separable Hadamard matrix, so every line feeds every other with equal energy.
• Echo density: one or two Schroeder allpasses inside every line (two in the Cave and on the Plate) multiply the echo density, so the tail is dense from the start and never rings.
• Damping: 3-band damping in each line sets T60 separately for lows, mids and highs, with per-space crossovers.
• Modulation: slow, cubic-interpolated modulation of the line lengths (0.15–0.6 Hz, at most a few tenths of a millisecond) keeps the tail from sounding static without audible chorus.
• Energy: analytic energy normalisation keeps the level constant when DECAY or DENSITY changes.
• Input: before the network, the input passes through a pre-delay and a chain of diffusing allpasses. Part of the early field also feeds the network, so the tail grows out of the reflections.

Late onset. The late field starts a space-specific time after the direct sound: 6 ms in the Studio, 18 ms in the Hall, 30 ms in the Church. This onset halves as the microphone moves to the far end. PRE-DELAY is added on top.

The late field is N-channel on both sides:

• Inputs: every input channel (up to 16 in the engine) has its own pre-delay, its own diffuser chain and its own input vector into the network, a different Walsh row. Two input channels therefore excite the room differently.
• Outputs: every output speaker (up to 15 main channels) receives its own decorrelated output from mutually orthogonal Walsh rows.

Why a network and not rays for the tail? After a few hundred milliseconds, a real room's field is statistically diffuse: the same everywhere, from every direction. A tuned high-density network reproduces exactly that, with no noise, at any length, for 1–2 % of a CPU core. Tracing the whole tail would cost far more and sound the same.

DISTANCE is the heart of modouVerb. It is the source-to-microphone distance in metres. The dial is logarithmic: equal steps multiply the distance by the same factor, which matches how we hear distance.

The physics

The engine starts from Barron's revised theory of sound energy in rooms:

• Direct energy falls as 1/r².
• Reverberant energy is set by the critical distance r_c = 0.057 √(V / T60), with V the polyhedron's real volume. It falls slowly with distance, as e^{−0.04 r / T}.
• Late share: the part of the reverberant energy arriving after 80 ms is e^{−1.11 / T}.
• Early energy is not a formula. It is the actual summed energy of the traced reflection pattern at that seat.

The musical shaping

• The physical direct-to-reverberant ratio is scaled and bounded per space. The closest position is never completely dry and the farthest never completely washed out.
• As the microphone moves back, part of the early energy moves into the late field: −3 dB of early energy at the far end. This makes distance easier to hear.
• Partial loudness compensation keeps the total level from collapsing as you move away. A distant source sounds distant, not simply quieter.
• The direct sound loses high frequencies with distance, up to −4 dB at 8 kHz in the Studio and −9 dB in the Church, Cave and Tunnel.

Decay changes the room, not just the tail

DECAY does not simply stretch a delay time. Turning it up grows the room itself — width, depth and height scale together, so the shape is kept — and turning it down shrinks it; the early reflections are re-traced through that resized polyhedron. DISTANCE's own metre range (the numbers printed under the dial) grows or shrinks with the room. What does not move is the microphone: its actual position in metres is preserved as DECAY changes, so a singer standing 20 m back in a small hall is still standing 20 m back once DECAY turns that hall into a cathedral. Only DISTANCE's normalised position — where the dial sits within the new range — shifts to keep that true.

Example — Concert Hall

The stage shows the current RT60 and the DIRECT / REVERB ratio (D/R) for your settings. The ratio crosses 0 dB near the room's critical distance, and in the Concert Hall that is about 4–5 m.

In modouVerb the microphone is a real part of the model. Every arrival that has a direction, meaning the direct sound and every early reflection (specular and diffuse), is picked up through the capsules' polar patterns before it reaches the speakers. Turning a directional microphone away from the source lowers the direct sound by more than 12 dB, darkens it, and turns the whole reflection image. The late field has no direction. It reaches the speakers through the network's decorrelated outputs.

Mic modes

The MIC panel shows what AUTO chose, for example IN Stereo → OUT 7.1.4. An explicit mode overrides AUTO. For example, you can listen to a stereo source with a mono microphone, or turn a mono source into a full immersive room.

Patterns

The three pattern buttons change meaning with the mode:

Directional capsules also darken off-axis, as real pressure-gradient microphones do. Every pattern gets an automatic early-field make-up so that its average room level matches an omni's. DISTANCE therefore means the same thing whichever pattern you choose. The immersive array is energy-normalised for every arrival direction, so a sound moving around the room never falls into a hole between speakers.

Heading — 360°

The heading turns the microphone on the spot. 0° points it at the source, and the value reads as degrees to the left (L) or right (R), up to 180° (pointing away). Set it with the dial in the MIC panel, or by dragging the microphone glyph on the 3D stage. Double-click either one to return to 0°. Some examples:

• A cardioid turned 60° away hears the source off-axis and one side wall head-on.
• A figure-8 turned 90° is deaf to the source and hears only the room: a pure ambience microphone.
• In IMMERSIVE mode, turning the array rotates the entire room around the listener.

Position and height

Where the microphone stands is set by DISTANCE (how far from the source), MIC bearing (in which direction from the source) and MIC HEIGHT. A higher microphone hears less of the floor reflection and more of the ceiling. In the church it moves up into the vault. See Placement.

There are two sets of loudspeakers in modouVerb. The output speakers are your monitoring layout, which the microphone renders to. In the Immersive edition there are also input speakers: loudspeakers standing inside the virtual room that play your input channels into it.

Output layouts

Channel directions follow Dolby Atmos and ITU-R BS.2051. Azimuth is positive to the left, and the heights are at 45° elevation.

The LFE channel receives no reverb. Reverberation is not a low-frequency-effects signal, and bass management belongs to your monitoring chain. Audio Unit hosts can carry 7.1.4 and 9.1.6 only, because Core Audio has no 7.1.6 or 9.1.4 layout. VST3 carries all four.

Input speakers — your channels, installed in the room Immersive edition

In the Immersive edition every input channel is treated as a loudspeaker installed in the space, like a real speaker system hung in a real hall:

• Mono is one speaker, C.
• Stereo is L and R.
• 7.1 is seven speakers around the room.
• 7.1.4 adds four speakers overhead.

Each speaker keeps its Atmos direction as seen from the microphone, with 0° pointing toward the SOURCE. It stands where that direction meets the room: against a wall, and for the height channels on the ceiling or vault. It is pulled off the surface by 8 % of the distance (at least 0.3 m). The array therefore fits the space. In the Studio it is a small near-field array. In the Church the rears stand deep in the nave, and the tops hang in the vault. At an open tunnel end, the speaker stands at a capped distance instead. On the Plate, which has no walls, the speakers are placed on a circle at the source-to-mic distance.

Every placed speaker is a complete source:

• its own direct path to the microphone;
• its own traced early reflections, from where it actually stands;
• its own input into the late network, with its own pre-delay, diffusion and input vector.

This is what an N × M impulse-response set would try to capture. Here it is computed, and it follows the room, the microphone and the placement. The LFE input is not placed.

Standard — five steps to a placed sound

1. Insert or send. Put modouVerb Standard on a track as an insert, or on an AUX return. On a return, switch on 100% WET · AUX.
2. Choose a space. Click one of the eight tabs. The small number under each name is its current decay time.
3. Set DISTANCE. Turn the big orange dial. Close is present and dry. Far is distant and roomy. Watch the D/R readout cross 0 dB around the room's critical distance.
4. Shape the tail. Use DECAY for length, TONE for darker or brighter, DENSITY for grainy or smooth, and PRE-DELAY for separation. Add DYNAMICS if the tail crowds the source.
5. Place and point (optional). Drag the SOURCE and MIC pucks in PLACEMENT, set their heights, and turn the microphone in the MIC panel. RESET returns to the designed placement.

Immersive — a stereo send into a 7.1.4 return

1. Create a 7.1.4 (or 9.1.6) return/aux track in your host and insert modouVerb Immersive. It opens as 7.1.4 in → 7.1.4 out.
2. Switch on 100% WET · AUX.
3. Send stereo tracks to it. With MIC mode on AUTO, the microphone becomes an immersive array, because the output has more than two main speakers. Every speaker of the bed receives its own part of the room.
4. Choose a space and DISTANCE exactly as in Standard. The IN/OUT meters show every channel.

Lite — two decisions

1. Choose a place: ROOM, HALL, CHURCH or PLATE.
2. Turn DISTANCE from CLOSE to FAR until the source sits where you want it. That's all.

Header

• Logo: modouVerb, always visible so you know the plug-in is loaded (the edition itself shows in the window title and the installed bundle name).
• ‹ Preset ›: step through the presets, or open the menu for factory presets (by category) and your user presets. An asterisk (*) after the name means you have changed something since loading it.
• Save: saves the complete current state as a user preset.
• 100% WET · AUX: removes the direct sound for use on a send/return.
• ADVANCED: opens the Advanced panel over the deck.
• LAYOUT [A] [B]: a permanent toggle between the Console and Distance-rail layouts — see Layouts A and B below.
• Gear icon: opens the utility panel (licence status and activation).

Space tabs

The eight spaces, each showing its current mid-band decay time. Switching spaces is seamless: a second engine fades the new space in over 20 ms while the old space's tail fades out over 350 ms. A running reverb never cuts off.

The deck

• PLACEMENT (bottom left): the SOURCE and MIC joysticks with their height sliders, and RESET. See Placement.
• DISTANCE: the main control, shown in metres (or centimetres on the Plate), with the range of the current space below it.
• Macros: PRE-DELAY, DECAY, TONE, DENSITY, DYNAMICS.

Advanced panel

Opened with ADVANCED. It holds PRE-DELAY, EARLY, LATE, WIDTH, MODULATION, LOW CUT and HIGH CUT. Close it with Done or the ADVANCED button. (LAYOUT [A] [B] is its own permanent toggle in the header, not part of this panel.)

Layouts A and B

Layout A (Console) puts the space tabs on top and the controls on a deck below the stage. Layout B (Distance rail), shown above and open by default on a fresh load, gives the stage more room and turns DISTANCE into a rail marked in metres, which is handy for precise depth staging. A permanent LAYOUT [A] [B] toggle sits in the header in both, so switching back and forth costs one click. Both layouts control the same parameters. The window is 1120 × 720 pixels (Lite: 560 × 460), resizable from the edge or from Window Zoom in the Utility panel.

The stage draws the current space as a wireframe of its real polyhedron, with the source (orange) and the microphone (with its heading and pattern) where the engine actually puts them. Its readouts:

• Top left: the space's name and character.
• Top right: the current RT60 and DIRECT / REVERB ratio.
• Bottom: the shape and size of the room.

Camera

The camera only changes the view, never the sound. On the Plate the view is fixed, looking down on the plate.

IN / OUT meters

Small peak meters at the top of the stage show every input and output channel, labelled with the format (Mono, Stereo, 7.1, 7.1.4 …) and the channel names (L, R, C, Lfe, Lss, Rss, Lrs, Rrs, Ltf, Rtf, Ltr, Rtr …). They adapt to up to 16 channels.

RAYS — the sound, made visible

The RAYS panel slides out of the stage's left wall. Click its tab to show or hide it. ON/OFF switches the animation. The rays are traced through the same room model that the diffuse early field uses. They are driven by your signal: each onset in the input fires a pulse from the source, up to 24 pulses in flight at once, and silence fires nothing. In the Immersive edition every placed input speaker fires its own rays, in its own colour, triggered by its own channel.

The rays are for display only. Switching them off changes nothing in the sound and saves some graphics load.

MIC panel

The MIC panel slides out of the stage's right wall. It is shown by default. It contains:

• the mode buttons: AUTO, MONO, STEREO, plus IMMERSIVE in the Immersive edition. When AUTO is lit, the resolved mode is outlined.
• the three pattern buttons, whose names follow the mode.
• the heading dial: drag it round, nudge it with the wheel, double-click to reset.
• a status line such as IN 7.1.4 → OUT 7.1.4 · 11 input channels placed at Atmos positions.

The PLACEMENT section has two joysticks drawn over the current room's floor plan, a HEIGHT slider next to each, and RESET. The pads show where the engine really puts the source and the microphone. Both are kept inside the polyhedron, at least 0.3 m from every surface, so a puck stops at a wall.

All placement parameters can be automated. Changes are crossfaded over 40 ms in real time, and are sample-exact in an offline bounce.

These are the parameters of modouVerb Standard and Immersive as the host sees them, with their ranges and defaults. Lite is described in its own chapter.

Main

Microphone

Placement

Advanced

All parameters are smoothed per sample, so every one of them can be automated without zipper noise or clicks.

modouVerb Standard and Immersive include 17 factory presets in six categories. A factory preset sets the space, DISTANCE, DECAY, TONE, DENSITY, DYNAMICS and 100% WET. It resets the Advanced parameters to neutral and uses the space's designed placement. It does not change the microphone mode, pattern or heading, so a preset keeps your monitoring setup. The metre, decay and D/R figures below are computed by the engine for each preset.

Preset notes

Most musicians do not want to think about volumes, materials and polar patterns. They want the vocal "a bit further back, in a nice hall". Lite is built for exactly that. It has two controls:

• Place: ROOM, HALL, CHURCH or PLATE.
• DISTANCE: a big dial from CLOSE to FAR, showing metres (centimetres on the Plate).

Everything else follows the place. It runs the full modouVerb engine with a microphone chosen automatically: a cardioid, as an XY pair on a stereo output, in the space's designed placement.

The ROOM decay is doubled from the Studio's natural 0.36 s. On its own the treated studio is almost too dry to hear as "reverb", and 0.7 s is the small room musicians expect. The pre-delays grow with the size of the place, to keep the source clear of its reverb.

Lite has no dry/wet control, and doesn't need one. For a send/return, simply turn DISTANCE further out. Lite exposes exactly two parameters to the host (Place and Distance), so automation lanes stay simple. It has one program, "Default", and no preset menu.

Rule of thumb for Lite: vocals and lead instruments sit between CLOSE and the middle. Pads, choirs and backing parts sit from the middle toward FAR.

Insert or send?

Insert modouVerb on a track when that sound needs its own place, for example a lead vocal in a specific room at a specific distance. The direct sound passes through the distance model, including its level and high-frequency loss. Send to modouVerb on an AUX return with 100% WET on when several tracks should share one room. The send level sets how much of each track reaches the room, and DISTANCE sets how deep the room sounds.

Depth staging: one room, many seats

The most powerful technique in modouVerb is also the most natural one. Use the same space on several instances, and set a different DISTANCE for each group of instruments. The late field, the room's "signature", stays the same across all instances, so everything sounds as if it is in one building. The direct level, early reflections and brightness give each group its own depth. In a Concert Hall, for example:

Add left/right placement with Source X: move the violins' source left and the cellos' right, and the reflections come from the correct walls, not just a panned dry signal.

Vocals

• Pop / rock lead: Vocal Plate or Close Vocal Room. PRE-DELAY 15–40 ms keeps consonants clear of the reverb. DYNAMICS 30–50 % lets the reverb bloom between phrases.
• Ballad: Default Hall, DISTANCE 0.25–0.35, TONE slightly dark.
• Backing vocals: the same hall as the lead, DISTANCE 0.2–0.3 further out than the lead.

Drums

• Room mic: Drum Room or Loft Warehouse, STEREO XY. Blend under the close mics.
• Ambience only: MONO or STEREO with the Figure-8 / Blumlein pattern turned 90° from the kit: very little direct sound, a lot of room.
• Snare: Snare Plate on a send, or the Chamber with DENSITY high.

Orchestral and acoustic

Dry orchestral samples come alive when each section gets its own instance of the Concert Hall, with its own Source X (seating) and DISTANCE (depth). Use Orchestral Hall as the starting point. Keep DECAY equal on all instances so the hall stays one hall.

Post-production and sound design

• Matching dialogue to picture: choose the space nearest the location, set DISTANCE to the camera distance, and turn the microphone as the boom would face. A figure-8 at 90° gives off-screen "room tone" from the same space.
• Movement: automate DISTANCE, Source X/Y or Mic Bearing. Every move is re-traced and crossfaded, not faked with volume. The Tunnel is ideal for passes and fly-bys.
• Rotation: automate the microphone heading for an ambience that turns around the listener, which is especially striking in IMMERSIVE mode.

Immersive mixing Immersive edition

• Stereo send → 7.1.4 / 9.1.6 return is the most common setup. Every stereo track sent to the return is played into the room by two speakers (L/R), and the immersive microphone array renders the room into every speaker of the bed, including the heights.
• Bed reverb: send a 7.1 or 7.1.4 bus with a matching input. Each channel is a speaker in the room, so the reverb keeps the direction of each part of the mix.
• Height content comes from real ceiling and vault reflections: strong in the Church and Hall, subtle in the Studio. For more height, raise the microphone or use a tall space.
• Focus vs envelopment: the WIDE pattern gives maximum envelopment. FOCUSED gives the sharpest direction per speaker.
• Monitoring in stereo: switch the MIC mode to STEREO to check the stereo compatibility of the same room.

modouVerb Immersive has one main input bus and one main output bus. The host decides their formats. The plugin opens as 7.1.4 → 7.1.4 and accepts:

General procedure

1. Create an AUX / FX / return track whose channel format is your bed format (7.1.4 or 9.1.6).
2. Insert modouVerb Immersive. If your host lets you choose the plugin's input format, choose Stereo for a stereo-send return, or 7.1 / 7.1.4 for a bed.
3. Switch on 100% WET · AUX.
4. Send tracks to the return. Check the MIC panel's status line: it should read, for example, IN Stereo → OUT 7.1.4 with IMMERSIVE outlined.
5. Check the OUT meters: every main channel should move, and LFE stays silent by design.

Signal flow

IN ─┬──────────────── DIRECT  (per-speaker mic pickup · distance level · air absorption) ───────────┐
    │                                                                                            ├─ OUT
    └─ INPUT BAND ─┬─ EARLY FIELD ─ MIC (polar patterns, per speaker) ─ tone ─ level ─────────────┤
                   │    ├ specular: image sources on the room polyhedron (order ≤ 3, Tunnel 4)   │
                   │    └ diffuse:  ray tracing "diffuse rain" (384 rays · 5 bounces)           │
                   │         └ part of the early field feeds the late network                    │
                   └─ PRE-DELAY ─ DIFFUSION ─ HIGH-DENSITY FDN ─ speaker route ─ tone ─ DYNAMICS ─ level ┘
                        16 lines · Hadamard · in-loop allpasses · 3-band damping · modulation
                        N inputs (own pre-delay, diffusers, Walsh input row per channel)
                        N decorrelated outputs (≤ 15 mains; LFE silent)

Specifications

Validation

Every release is checked objectively before listening tests:

• DSP test suite: 274 checks. FDN stability and resonance, RT60 per band, echo density, early-reflection geometry and timing, the distance model, tone, dynamics, click-free parameter changes, sample rates from 44.1 to 192 kHz, the microphone and immersive rendering, placement and rays.
• Apple auval (strict): passed for all three editions.
• pluginval at strictness 10: passed with 0 warnings for AU and VST3 of all three editions.
• Host harness (AU and VST3): layouts, 6 sample rates × 4 block sizes, irregular blocks, automation, bit-identical state restore, programs and the editor.

Known limitations (v1.0.6)

• The late field is statistical, not geometric. Position changes its level and onset, not its texture.
• Geometric acoustics does not model diffraction or low-frequency room modes. The low end of each space is shaped by its tuned late field.
• The immersive output is a channel bed, not Ambisonics or Atmos objects.
• The window has a fixed size (960 × 960; Lite 560 × 460). User presets cannot be renamed or deleted from the interface.
• Not yet tested in real DAWs. AAX is built and PACE-signed but not yet tested in Pro Tools.