User Manual

Version 0.9.0

Spatial Convolutional Reverb

2026-07-16

build 977a3f4*

1 Introduction

Hartley DSP created THeVerb to allow musicians and producers to make digital instruments and recordings sound alive, with the warmth and character that comes from human performance in a real space. With today’s technology recording live isn’t always an option and, even when it is, it can be difficult, expensive or creatively limiting. THeVerb lets you bring digital sources into realistic acoustic environments, so that you can have the best of both worlds.

1.1 What Is THeVerb?

THeVerb is a unique spatial convolutional reverb plug-in. It allows you to place and move sound sources within a space, simulating the way sounds are affected by the distance and direction of the source from the listener, and the reverberation that occurs as sound waves reflect off the walls, ceiling and floor. Our brains are exquisitely sensitive to these spatial cues. The tiny differences they create in the sounds reaching our left and right ears create a vivid sense of space even when we are not consciously aware of them. By combining different instances of THeVerb, you can recreate the interaction of sounds from different musicians playing together at the same time, in the same room, even if they were recorded separately.

2 Installation and Activation

This section walks you through the process of installing and activating your THeVerb plugin. Activation is required to unlock the full functionality of the plugin, but you can also use it in Trial mode to evaluate it before purchasing.

2.1 Installing the Plug-in

Visit hartleydsp.com/products to download the latest installer. Run the installer and follow the prompts to install THeVerb on your system. The installer includes the plugin itself, as well as the factory IR library (a set of different acoustic spaces you can use with your plugin), and this user manual.

The installer will place the factory IR library in a folder within your Windows user account: %appdata%\Hartley DSP\THeVerb\IRLibrary (this typically corresponds to a location like C:\Users\<username>\AppData\Roaming\HartleyDSP\THeVerb\IRLibrary). In the HartleyDSP folder we also store other information your plugin needs, such as your settings and presets.

2.2 Activating Your License

When you first open THeVerb (typically adding it as an insert in your DAW) it will run in Trial mode. This mode allows you to use the plugin with some limitations to evaluate it before purchasing, to activate your license when you buy a license (removing the limitations), and to reactivate if your system changes or the license information is lost. When in Trial mode the plugin displays an orange indicator and “Trial Mode” text at the bottom of the interface.

To activate click on the orange “Activate” button (marked X, below) at the top of the interface, just to the right of the THeVerb logo. This will open the activation dialog, where you will enter your email address and license key. You can find your license key in the confirmation email you received when you purchased, or in your account on our website. After entering your information, click “Activate” to complete the process. If the activation is successful, you will see a confirmation message and the plugin will be fully functional.

2.2.1 Activating Beta Versions

2.2.2 Trial Mode Experience and Limitations

The plugin is fully functional in Trial mode, with the following exceptions: - A limited number of rooms are available. In the full version 45 rooms are included. - Spatial features (XY source position, distance attenuation, distance delay and binaural microdelays)are available for 30 minutes in each session. After 30 minutes spatial features are locked and the reverb operates in mono. To continue evaluating, start a new session. - The “Spatialize” feature for User IRs is not available in Trial mode.

3 Quick Start for Experienced Users

First install and activate your plugin (see Installation and Activation as described above).

Quick workflow:

1. Choose a factory room (or load a User IR).
2. Set source position in the XY pad (use headphones to hear the spatial effects clearly).
3. Adjust Direct/Room Mix and Room Tone to fit the track.
4. If you are working with several related tracks, enable Sync so room or preset changes propagate across synced instances.
5. Set gain match and distance options as desired. With attenuation on, the plugin will make your sound quieter, so you may want to turn off attenuation or use one of the gain match options to compensate. Binaural delays provide a strong spatial effect, especially when mixing for headphones, but overall distance delay is barely perceptible and can cause phase issues, so it can be turned off unless realism is a priority.
6. Trim reverb time and adjust tail shape to taste.

4 Overview

When you open up the plugin in your DAW, you will see the main interface which is designed to be compact and intuitive. All the controls you need are on a single screen, a few sections expand when clicked to provide options. The main panels are labelled A-F in the figure below; individual controls are numbered within each panel. The Header panel (A) provides product information, settings and help. Just below that the Visualizer panel (B) shows how the plugin is working. Beneath that the central area, panels C,D and E provide the main controls used to configure the plugin, in panel E, Direct/Room Mix acts very like a wet/dry, mix blending the direct signal with reverberation (the direct signal is not strictly dry because it normally includes microdelays and attenuation). At the very bottom of the interface is the Footer panel (F) which provides information about the plugin’s operations, modes and version.

4.1 Header Panel (A)

• UI Scale control. Select a scale that works for your screen and preferences. On a laptop with limited space, you may need to use a reduced scale such as 85%, on a large desktop monitor with high resolution, you may prefer to use a larger scale such as 150% or 200%.
• You can also access Help () and Settings () from the header.

4.2 Visualizer Panel (B)

• Direct Signal Visualizer on the left (1)
• Room Signal Visualizer on the right (2).

These show the effect of your spatial settings and convolution in real time, so you can adjust them to get the sound you want.

4.3 Control Panel (C)

In the Control Panel you can adjust various parameters affecting the direct and room signals:

• Presets (3) allow you to save the current settings, or recall settings you have used previously.
• Input Mono/Stereo (4) determines whether your input signal will be treated as mono or processed via two independent stereo channels. For many situations mono is more realistic (because the sound comes from a single location), but stereo can produce more interesting and creative results.
• Gain Match radio buttons (5) allow you to select options that increase the level of the plugin’s output to match the input level in different ways (view tooltips for details).
  
• Distance (6) independently toggles different components (attenuation - , distance delay - and binaural delays- ) of the direct signal processing pipeline - when they are all on, processing is realistic giving a vivid sense of the source’s location. When they are all off, the direct signal is equivalent to the dry input.
• Room Tone (7) provides low cut and high cut filters allowing you to adjust the tone of the room signal, removing low and high frequencies respectively.
• Reverb and Fade Time controls (8) allow you to trim the effective duration of the impulse response and the shape of its tail, shortening the reverberation time.

4.3.1 Presets: Create, Save and Delete

Use the Presets control to capture useful combinations of room, position and processing settings so you can recall them quickly.

4.3.1.1 Create and Save a Preset

1. Set up the plugin the way you want (room, source position, mix and processing controls).
2. Click the Presets control to open the popup, then click New Preset .
3. In the Save Preset dialog, enter a name.
4. Choose what to store using the three groups.
5. Group meanings:
   • Room: saves the current room reference. If a User IR is selected, this stores the User IR reference (when available).
   • Position: saves XY source position.
   • Processing: saves processing controls (mix, mono/stereo mode, distance options, gain match, filters and reverb-time controls).
6. Click Save.

If a preset with the same name already exists, THeVerb asks whether to overwrite it.

4.3.1.2 Load a Preset

Open the Presets popup and click a preset row marked . If that preset includes a room reference, THeVerb also loads the associated room (or User IR reference) and updates controls accordingly.

If you change settings after loading, an asterisk (*) appears next to the preset name to indicate the current state has been modified.

4.3.1.3 Delete a Preset

1. Open the Presets popup.
2. Move the mouse over a preset row icon to reveal delete .
3. Click , then confirm deletion in the dialog.

The built-in Default preset is protected and cannot normally be deleted.

4.4 Spatial/Room Panel (D)

The Spatial/Room Panel (D) is the heart of the interface, where you choose the acoustic space and place your sound source within it:

• Room Selector (9) choose from a library of factory rooms, or load your own impulse responses.
• Sync button (10) you can synchronize the preset and room selection with other THeVerb instances in the same project (), or keep them independent (). When synced, changing the room or preset in one instance will change it in all synced instances, allowing you to easily create a consistent acoustic environment for all synced tracks.
• XY Pad (11) allows you to move the sound source around in the horizontal plane of the room, changing its distance and direction from the listener. The listener’s position is just below at the bottom-centre of the pad, left is left, right is right. The size and aspect ratio of the sound stage depends on the selected room.
• Instance Bar (12) shows you the name of the current instance (the track name if your DAW supports it) and reveals locations used by other instances of THeVerb in the same project - this can make the interface rather cluttered so it is hidden by default - click the closed eye icon () to make it active ().

4.4.1 Room Selector, IR Library and User IRs

The Room Selector is where you choose the acoustic environment that determines the room signal. Open the browser and find the factory bundle: these are curated rooms with impulse responses modelled on recording and performance spaces with different characteristics. Select a room by clicking on its name in the middle column. The room selector remains open so you can switch between rooms and audition them with your track playing.

If you want to use your own impulse response, switch to User IR mode in the Room Selector and load your file. In the full product, you can then enable Spatialize to map that IR into THeVerb’s spatial model, so movement on the XY pad still produces meaningful positional cues, affecting both direct and room signals, rather than a static stereo reverb. This is useful when you want the character of a custom IR but still need consistent placement control across multiple tracks. The spatialization synthesizes spatial cues based on statistics of thousands of IRs across different simulated spaces, so that your IR behaves like the more detailed and precise spatial models built into our library.

4.5 Output Panel (E)

In the Output Panel (E) you can adjust the balance between the direct and room signals with the Direct/Room Mix control (13). The higher the value, the more room signal and less direct signal you will hear, so it acts very like a wet/dry control, although the direct signal is not strictly dry because it normally includes microdelays and attenuation.

In the Metering Section (14) you can see the input, direct signal, room signal and output levels. The meters display the RMS level of the signal (coloured bars) in dBFS and an indication of the peak signal (white line). From left to right the meters show:

• Input (): the level of the signal coming into the plugin.
• Direct (): the level of the direct signal (after processing).
• Room (): the level of the room signal (reverberation only).
• Output (): the level of the final output signal (after mixing direct and room signals and applying gain match).

4.6 Footer Panel (F)

The footer at the bottom of the interface shows information about the plugin’s status, such as whether it is in Trial mode, the convolution and graphics modes, the build name and type. These can be useful for troubleshooting and support. On the left hand side of the footer is the notification area. This displays information (such as license status), warnings (for example, if a library file cannot be found) and error messages (for example, “IR Library path not found: {path}”). It is normally closed and just displays a count of the number of messages of each type. Click on the notification area and scroll to see the messages. If a message spans several lines you can click to expand it. When a new warning or error message is generated you will see it briefly displayed to the right of the notification area, and the count of warnings or errors will increase.

5 In Depth

This section explores the ideas and techniques behind THeVerb’s processing and provides practical guidance for getting the most out of the plugin. For a reference to the interface controls, see the Overview above.

5.1 How THeVerb Works

THeVerb processes two separate signals. The direct signal is the sound that reaches the listener directly from the source, without bouncing off any surfaces. The room signal convolves the input sound with an impulse response (IR) that captures the acoustic characteristics of a given space, simulating the reverberation you would hear in that room. The two signals are mixed together to create the final output.

Using the XY pad you can place the sound source anywhere in the horizontal plane of the room, and THeVerb adjusts both signals accordingly. The direct signal is processed with delays and attenuation to simulate the effect of distance and direction. The room signal uses a different IR, or a blend of IRs, matched to the source’s position. THeVerb includes a library of impulse responses for a curated set of rooms, and you can also load your own IRs.

5.2 Key Concepts

Convolution: at any moment the sound you hear is a combination of waves coming directly from sources (instruments, voices, speakers etc.) and reflections of earlier waves that have arrived at your ears after bouncing off surfaces in the room (walls, ceiling, floor, etc.). Mathematically, and in nature, this combination works by adding together the changing waves from the present and recent past according to a fixed pattern of thousands of “echoes” generated by the reflections. Some reflections arrive more quickly and are stronger than others. Mathematically each “echo” multiplies the sound level by different amounts according to the surfaces the waves have hit along the way; different surfaces, and the air itself, absorb different frequencies to different degrees. So, at each moment in time, we are adding together the past waves after they have been multiplied by a factor that depends on how much energy has been absorbed or reflected along the way.

Impulse Response (IR): the impulse response is the fixed pattern of echoes that occur in a given space, and it depends on the sound source’s location, the listener’s location, the geometry of the room and the acoustic properties of the surfaces. But it has a very simple real-world equivalent: the sound you hear at the listener’s location when a very short burst of noise (like a balloon popping) is emitted at the source position. By imposing this pattern on every new wave emitted by the source, we can simulate the reverberation we would hear in the room with any new sound.

Reverberation: because there are so many reflections, and they are so close together, we don’t typically hear individual echoes, but rather a gradually dying reverberation which smears the original sound over a few seconds.

“Dying” and “smearing” don’t sound very pleasant, but in fact reverb can be a very beautiful and natural sound. We never, in normal life, hear a sound without any reverb, and we miss it when it’s not there. The absence feels very cold, dry and unnatural. In many real-world settings, natural reverberation is very subtle, and, to achieve clarity in performance and recording spaces, steps are often taken to reduce it. Although we may not be aware of it, even this very subtle reverberation adds a sense of warmth, space and life to the sound. And with bigger reverb sounds (such as those we would only normally hear in a cave or a church) we become conscious of the effect; it typically adds a sense of significance or grandeur, although it can make individual notes hard to pick out. If you are mixing a slow ballad, you will probably want to add a longer reverb to the vocal, otherwise it will sound lifeless.

5.3 Reading the Visualizers

The Visualizer panel (B) shows the direct and room signals in real time. Here is how to read them in detail.

5.3.1 Direct Signal Visualizer

The Direct Signal Visualizer shows how distance and direction affect the sound that travels straight from the source to the listener. Time runs along the horizontal axis, with the whole window covering about 50 ms.

On the left of the plot, a tall white bar shows the relative level of the original source. To its right, a coloured bar represents the sound arriving at the listener’s ears: delayed by a few milliseconds (further to the right on the time axis), quieter (reduced in height), and - if the source is not directly ahead - very slightly earlier at one ear than the other. The narrowing grey “shadow” between source and listener indicates attenuation according to the inverse square law. Blue represents the left ear, orange the right; the slight offset between them shows the interaural time difference (ITD). Because these differences are tiny, the bars are bowed outward to make the ITD easier to see. As you move the source around the XY pad, the display updates to reflect the changing delay, attenuation and ITD.

5.3.2 Room Signal Visualizer

The Room Signal Visualizer shows the room signal - the sound that reaches the listener only after bouncing off surfaces. As sound waves interact with walls, floor and ceiling, they may be absorbed or reflected, with different surfaces reflecting different frequencies to a greater or lesser extent. The reflected waves may bounce several times before reaching the listener; the longer they travel, the more energy is absorbed. The visualizer has two parts: an impulse response envelope at the top, and a dynamic room signal at the bottom.

5.3.3 Impulse Response Envelope

The upper part of the room signal visualizer shows the impulse response envelope: a plot of the overall intensity of the IR over time. With room impulse responses the early reflections are typically more intense, and the sound gradually dies away. Imagine the sound of a balloon popping in a room. In a small living room with carpet and soft furnishings, the sound dies away very quickly. In a large cathedral you will hear it die away only gradually over several seconds.

5.3.4 Dynamic Room Signal

The animated lower part of the visualizer shows the effect of the impulse response on the input signal in real time. At the far left we see the initial reflections arriving a few tens of milliseconds after the sound was emitted, having bounced off one or two surfaces. But at the same moment we are also hearing sounds that have been delayed longer (to the right of the plot), sounds that have died away a little and have different spectral characteristics as some frequencies are absorbed more than others. These sounds add together to create the reverberation we hear at a given moment - the process is called convolution.

5.3.5 Spectral Colours

As well as the intensity of the sound, the impulse response also affects the tone of the reflections. A room with hard reflective surfaces such as stone or wood panelling will have a much brighter tone than a room with heavy curtains that tend to absorb high frequencies. In some cases the high or low frequencies may die away more quickly than mid-range frequencies, so that later reflections can have a warmer or cooler tone than the initial reflections.

In THeVerb these spectral properties of sound are represented by colours which correspond to wavelengths of light. Every part of the audible sound spectrum is mapped to a part of the visual spectrum, and sounds that combine different frequencies are represented by a corresponding combination of visual wavelengths. Warm colours - reds, oranges and yellows - correspond to rich bass frequencies; cooler blues and violet to bright treble frequencies; greens and turquoises to midrange frequencies. It’s also possible to see other combinations such as purple (blending bass and treble), white (broadband sound with energy across the spectrum) and pink (broadband with greater energy in the lower frequencies). If you adjust the Low Cut and High Cut filters (see Room Tone, below) you can see their effect on the IR envelope and the dynamic room signal in the visualizer.

5.4 Spatial Positioning

THeVerb’s spatial model simulates how a sound source’s position affects what the listener hears. This section explains how the XY pad maps to the room and how the three distance cues interact.

5.4.1 How the XY Pad Maps to the Room

The XY pad represents the horizontal plane of the selected room. The pad is square, but the sound stage - the area the source can move within the room can be rectangular. The size and aspect ratio of the sound stage varies by room, in some rooms it can be much smaller than the space (for example in a venue where the stage is much smaller than the audience area). In the current version of THeVerb you cannot visualize these aspects of the room’s geometry (although the overall dimensions are diplayed in the Room Browser), so it is best to rely on your ears to evaluate the effect of source placement in different rooms. We plan to include a more detailed room visualisation in a future version of THeVerb.

The listener sits below the bottom edge of the pad, facing the sound stage. The listener’s position is fixed - you cannot move it. The puck represents the sound source: moving it upward increases the distance from the listener; moving it left or right changes the source’s direction. At the bottom centre of the pad the source is at its closest point to the listener, directly ahead.

Because the listener is below the pad rather than at its edge, even a source placed at the very bottom of the pad is some distance away. This minimum distance is typically a couple of metres leading to some attenuation of the direct signal (which can be offset the using Gain Match feature).

5.4.2 Movement

THeVerb allows you to move the source seamlessly in real time. You should notice the direct signal provides a very detailed impression of movement, while the effects on the room signal are more subtle in most rooms. You can automate the X and Y parameters in your DAW, or - if it permits it - link them to a MIDI controller for real-time input.

5.4.3 Distance Cues and Their Trade-offs

The Overview describes the three distance toggles in the control panel. Here is what to expect when you use them, and why you might choose to turn one off.

Distance attenuation () follows an inverse square law: double the distance and the direct signal drops by about 6 dB. This is the most immediately audible distance cue. With it on, moving the source further away makes it noticeably quieter, which shifts the balance between direct and room signals toward the room. This is realistic, but it means the output level changes as you reposition the source. If you need a consistent level while still using the other spatial features, turn attenuation off and consider using one of the Gain Match modes instead (see Gain Management, below).

Distance delay () delays the direct signal according to the speed of sound. At typical room distances (a few metres) the delay is only a few milliseconds, and on its own it is barely perceptible. However, the presence or absence of this delay can affect the relative phase of signals when combining THeVerb’s output with other tracks or with a parallel dry signal. Turning it off preserves phase alignment at the expense of physical realism. Unless phase interaction is causing problems, the default (on) is a reasonable choice.

Binaural delays () model the interaural time difference (ITD): when a source is off to one side, sound arrives at the nearer ear a fraction of a millisecond earlier. This is one of the strongest directional cues our hearing system uses, and on headphones the effect is vivid - the source is clearly placed to one side. With binaural delays off, the direct signal arrives at both ears simultaneously and the sense of direction comes only from the room signal. You might turn them off if you are mixing primarily for speakers (see below) or if you want a more conventional reverb sound without strong lateralisation.

5.4.4 Headphones vs Speakers

THeVerb’s spatial model is binaural: the direct signal processing is designed to place sound at each ear independently, producing the most vivid spatial impression on headphones. On speakers, acoustic crosstalk means each ear hears both channels, which dilutes the ITD cues. The room signal still conveys a sense of space on speakers, and the overall effect remains useful, but the precise left-right placement of the direct signal is less sharp.

If you are mixing primarily for speaker playback, you may find that turning off binaural delays and relying on the room signal for spatial character gives a more natural result. If you are mixing for headphones - or for a binaural or immersive format - keeping binaural delays on will give the strongest sense of source position.

5.5 Shaping the Sound

The Overview describes THeVerb’s tone and time controls. This section provides more detail on how they interact and how to use them in practice.

5.5.1 Room Tone: Filters in Practice

The Room Tone filters (Low Cut and High Cut) shape the frequency content of the room signal only - they do not affect the direct signal. The filters are 12 dB/octave, giving a moderate slope that sounds natural rather than abrupt.

In practice, the most common use is managing the low end. Large rooms and rooms with hard surfaces can produce substantial low-frequency reverberation, which may muddy a mix. Raising the Low Cut filter cleans this up without affecting the direct signal’s bass content. Similarly, High Cut can tame overly bright reflections - useful if a room’s natural character is harsher than you want.

The effect of the filters is visible in the Room Signal Visualizer’s spectral colours: raising the Low Cut shifts the colour palette away from warm reds and oranges; lowering the High Cut removes the cooler blues and violets. This makes it easy to dial in the tone by eye as well as by ear.

5.5.2 Reverb Time and Fade

The Reverb Time control trims the effective length of the impulse response, shortening the reverberation. This is useful when you want the character of a large room but need a tighter tail for clarity in a mix. Very short trim values can produce a thickening or doubling effect rather than an audible reverb, which can be effective on vocals and close-miked instruments.

The Fade control adjusts the shape of the tail’s decay near the trim point, controlling how abruptly the reverb cuts off. A longer fade produces a smoother, more natural-sounding end to the reverb; a shorter fade gives a more defined cutoff.

When BPM units () are engaged, the Reverb Time control snaps to musically meaningful durations derived from the host tempo, so that the reverb tail aligns with the rhythmic structure of the track. This can be particularly effective for rhythmic material where a reverb tail that decays cleanly before the next beat or bar produces a tighter, more controlled sound. BPM units require a tempo from the host DAW; if no tempo is available, the control reverts to its standard proportional behaviour.

5.5.3 Direct/Room Mix

The Direct/Room Mix control blends the direct and room signals. At 0.0 you hear only the direct signal; at 1.0, only the room signal. It functions much like a wet/dry control, but with one important difference: the “dry” direct signal is not identical to the unprocessed input. When distance cues are active, the direct signal carries attenuation and delay processing, so even at a mix of 0.0 the output reflects the source’s position.

For subtle room ambience - the kind of treatment where you want a sense of space without obvious reverb - values in the range 0.05 to 0.15 are a good starting point. For more prominent reverb, values of 0.3 and above bring the room signal clearly into the foreground. At the extremes, a mix of 1.0 (room only) can be useful as a send effect, or for creative treatments where you want pure reverberation.

The interaction with Gain Match is worth noting: if you are using Gain Match to Input, the compensation tracks the overall output level, so changing the mix does not cause the level to drift. With Gain Match off, increasing the mix adds room signal energy and the output gets louder.

5.6 Gain Management

THeVerb’s spatial processing changes the output level in ways that a conventional reverb does not. Distance attenuation makes the direct signal quieter as the source moves away, while the room signal adds energy. The Gain Match modes address this, but they serve different purposes depending on what you are trying to achieve.

5.6.1 Choosing a Gain Match Mode

Gain Match off (): the most realistic option. Level changes naturally as the source moves, just as it would in a real room. Best when realism is the priority and you are comfortable managing levels manually - or when THeVerb is the primary level control for the track.

Match to zero distance (): compensates for the minimum attenuation that occurs even when the source is at its closest point to the listener (the bottom centre of the XY pad). With this mode, the output at that nearest position matches the input level, but the signal still gets quieter as the source moves further away. This is a good compromise when you want to preserve the sense of distance but don’t want the constant baseline attenuation to throw off your mix balance.

Match to input level (): the output level tracks the input level regardless of source position. This uses an RT60-matched envelope follower - essentially a dynamics processor whose release time matches the room’s reverb time - so that the compensation decays gracefully during reverb tails rather than cutting them off abruptly when the input goes quiet. The effect is a little like a compressor, and it does affect the dynamics of the signal. Results depend on the character of the input and the reverb time: with short, percussive input and long reverb, you may notice the tail being shaped. Best when you need to drop THeVerb into a mix and have the level stay consistent without manual adjustment.

Match direct signal (): compensates the direct signal’s attenuation, boosting the entire output (direct and room together) by the same amount. The direct part of the output matches the dry input level, but because the room signal is boosted proportionally, the overall output is louder than the input. The net effect is that as you move the source further away, the level stays consistent but the sound becomes more reverberant - a useful behaviour when you want distance to affect character rather than volume. Like Match to Input, this mode uses an envelope follower to handle reverb tails smoothly.

A soft limiter prevents any gain match mode from producing excessive output in extreme cases (very large distance attenuation combined with a hot input signal).

5.7 User IRs

You can import your own impulse responses (IRs) to provide the room signal. IRs can be obtained online, and in principle you can create your own (beyond the scope of this manual). User IRs must be wav files with durations between 0.1 and 10 seconds, and they should be stereo for best results. The quality of the reverb will depend on your chosen IR, and not every wav file will produce viable results.

You can find some free IRs with Creative Commons licenses at operairlib.net and there are many other sources online. Such IRs do not inherently support the spatial features of THeVerb, but the full version of the plugin allows you to “Spatialize” User IRs, so that moving the source on the XY pad produces meaningful positional cues rather than a static stereo reverb. Spatialization synthesizes spatial cues based on statistics of thousands of IRs across different simulated spaces, but note that it cannot work in the same way as our own more precise spatial models (the necessary geometric information is not available). With spatialization, you should find that when the XYPad is in the bottom centre position the sound you hear is very similar to the original IR, the room signal varies subtly as you move the source location and the direct signal carries detailed spatial cues just as with the THeVerb rooms. Without spatialization you will be able to use THeVerb as a conventional convolutional reverb, but you cannot move the source.

5.7.1 Level Management with User IRs

When loading your own impulse responses, the output level can be unpredictable. THeVerb attenuates an imported IR if the expected room signal would be louder than the input, but even so, some User IRs produce substantially louder or quieter room signals than the factory rooms.

To avoid surprises: start with your DAW channel fader low and the Direct/Room Mix at a conservative value (0.10 or so). Audition the IR, then bring the fader and mix up to taste. If the room signal is persistently too loud or too quiet to blend comfortably with the mix control alone, consider adjusting the IR’s gain in an audio editor before importing it.

If User IR spatialization is active, resonant frequencies in the IR can interact with XY positions, so it is worth testing with representative audio across a range of source locations.

5.8 Presets in Depth

The Overview covers creating, loading and deleting presets. This section explains the three component groups and how to use them for more flexible workflows.

5.8.1 Component Groups: Room, Position and Processing

When you save a preset, you choose which of three independent groups to include:

• Room: stores the current room reference (or User IR reference, if a User IR is selected). When a preset with a Room group is loaded, THeVerb switches to that room.
• Position: stores the XY source position. Loading a preset with a Position group moves the source puck to the saved location.
• Processing: stores the processing controls - Direct/Room Mix, Input Mono/Stereo mode, distance toggles, gain match mode, filter settings and reverb time controls.

Because the groups are independent, you can create presets that store any combination. Some practical examples:

• Room only: build an audition shortlist of rooms for a project. Load each preset to switch rooms quickly without disturbing your current position or processing settings.
• Position only: save “this instrument lives here” references - a vocalist at centre-front, a guitar slightly left - that you can recall when switching between rooms or projects.
• Room + Position, no Processing: lock down where a source is in a given space, while keeping the freedom to experiment with mix, filters and reverb time.
• Processing only: store a favourite reverb sound for a given instrument, without locking it to a specific room or position.
• All three: capture a complete snapshot of the plugin’s state, for recall or for sharing a known-good starting point across sessions.

If you change any setting after loading a preset, an asterisk (*) appears next to the preset name, indicating the current state has been modified from the stored version. You can save over the existing preset to update it, or save a new preset under a different name.

5.8.2 Combining Presets

Because of the way different presets can include or exclude certain parameter groups, you can combine them when setting up a track. For example, you can load a preset that defines the room, gain matching, reverb time adjustments and filter settings, followed by another that controls only the location of the source. By setting up a reusable collection of presets, you can quickly specify the acoustic environment and spatial layout of an ensemble.

• location presets can be used for speaker locations (“PA Left”, “PA Right”, “Drums”, “Bass Amp”)
• room + processing presets can be used for acoustics (“Airy Quarter Note”, “Warm Tight Gain Matched”)

5.8.3 Presets and Sync

When Sync is enabled across multiple instances, loading a preset or changing the room in one instance propagates the change to all synced instances. See Multi-Instance Workflows, below, for more on how sync works.

5.9 Multi-Instance Workflows

THeVerb’s ability to run multiple instances in the same DAW project - each processing a different track but sharing the same acoustic space - is one of its distinguishing features. This section explains how to make the most of it.

Through the multi-instance bar () you can see all the instances in the project, and their XY source positions. The instance you are acting on has a solid blue puck; the other instances have hollow pucks. You can only move the active instance’s puck.

5.9.1 Sync: What Propagates

The Sync button () puts an instance into a shared pool. When any synced instance changes its room or loads a preset, that change is dispatched to all other synced instances. Unless reset by the preset parameters, each instance’s XY source position remains independent - the whole point is to place different instruments at different locations in the same room.

What syncs:

• Room selection: changing the room in one synced instance changes it in all of them, so every track shares the same acoustic space.
• Preset loading: loading a preset in one synced instance loads the same preset in all of them.

The selected preset will alter all the parameters included in that preset’s groups. If the preset includes a Room group, all instances will switch to that room; if it includes a Position group, each instance will move its source puck to the saved position; if it includes a Processing group, all instances will update their processing controls accordingly.

When Sync is off (), the instance is independent and neither sends nor receives changes.

5.9.2 Placing an Ensemble

The basic workflow for placing several instruments in the same room:

1. Insert THeVerb on each track you want to place in the shared space.
2. Enable Sync on all instances and select a room in any one of them - the rest will follow.
3. Position each source on its own XY pad. Use the Instance Bar () to see all source positions at once, so you can arrange the ensemble across the stage and avoid stacking sources on top of each other.
4. Adjust processing controls per instance as needed. Each instance can have its own Direct/Room Mix, distance settings, filters and reverb time, even though they share the same room.

The result is that each track sounds as if it were performed at a specific location within the same space. On headphones, the binaural processing gives a vivid sense of each source’s position; on speakers, the room signal provides a coherent shared ambience.

5.9.3 Mono vs Stereo in a Multi-Instance Context

THeVerb’s spatial model assumes a single source location. When the input is set to Mono, the signal is summed to a single channel before spatial processing, which produces the most realistic result - the sound genuinely comes from one point in the room. This is the natural choice for individual instruments, vocals, and any source that has a single physical location.

Stereo mode processes the left and right channels independently through THeVerb’s spatial pipeline. This can produce interesting and creative results with stereo sources such as drum overheads, stereo synths or stereo-recorded instruments, but because two independent channels are being placed at the same XY position, the spatial impression is different from what you would hear from a real single source and the stereo information can conflict with the spatial cues generated by the plugin. In a multi-instance setup where realism is the goal, Mono is usually the right choice for each track. Stereo can produce some interesting and often subtle creative effects.

6 The IR Library

THeVerb’s rooms are stored on your disk in the “IR Library”. The library is installed alongside the plugin and placed in a folder within your Windows user account:

%appdata%\HartleyDSP\THeVerb\IRLibrary.

The library is divided into bundles - curated collections of rooms with related characteristics. Several bundles are included with the plugin. A small subset of rooms (the “Trial Bundle”) is available in Trial Mode, before the full product has been activated. In addition, a few rooms are built into the plugin binary itself, so that basic operation continues even when the IR Library on disk is missing, incomplete or damaged (if a built-in room is being used in place of a library room, a notification will tell you so).

6.1 Included Rooms and Bundles

6.1.1 Included Bundles

The plugin comes with three curated bundles of rooms each including 15 rooms:

• Rooms & Booths: a broad palette of recording spaces with more varied acoustic properties and including very small spaces (booths) as well as medium and large live rooms with a variety of reflective and absorptive surfaces.
• Studios & Venues: a selection of recording and performance venues, inspired by real-world locations with a range of dimensions and acoustic characteristics. Studios often have extensive acoustic treatment so that even large spaces can sound quite dry. Treatment tends to control higher frequencies better than low frequencies so they tend to have a warm sound. Venues typically have more lively acoustics, and need to be large enough to accommodate a crowd - albeit sometimes quite tightly packed!
• The Works: an imagined complex of industrial and commercial buildings repurposed as rehearsal and performance spaces. The everyday materials and unusual dimensions create more intriguing and distinctive acoustics.

6.1.2 Included Rooms:

6.1.2.1 Rooms & Booths

• Amontillado Room: Small treated room, the sound stage squeezes up against the walls. Dry, warm, and very slightly claustrophobic.
• Cedar Booth: Wood surfaced isolation booth with a balanced tone and distinctive character.
• Cognac Booth: Despite its small size, this half-tiled booth has a lingering reverberation with a distinctive, evolving tone that combines initial bite with developing warmth. Compare with its brighter twin “Riesling Booth”.
• Drum Booth: Small room with acoustic treatment and some reflective surfaces. Designed for drums but works well with many instruments and can accommodate a small ensemble (if they are good friends).
• Ember Room: Large, high-ceilinged tracking room with moderate acoustic treatment and an unusual reflective floor which act together to provide tight reverb with a distinctive but neutral tone. Less is more.
• Light Frost Booth: Very lightly treated booth, with a tight, bright tone.
• Mahogany Room: This large tracking room has hardwood surfaces and only very light acoustic treatment but nonetheless achieves a warm, controlled tone.
• Mirage Room: Large tracking room, with moderate acoustic treatment. Reverb decays rapidly but with lingering warmth. Subtle.
• Oak Room: Small room with stone floor and wooden panelling. Neutral tone with a slight emphasis on mid frequencies and a useful short reverb time.
• Pine Room: Medium-sized room with stone floor and wooden surfaces. A taller cousin of Oak Room with a slightly longer, more open reverb. Neutral tone with presence in the midrange.
• Purple Booth: Tight and bright booth with a distinctive character. Deeply scooped mids reserve space for foreground instruments and vocals to shine.
• Red Booth: Treated isolation booth with a warm tone.
• Riesling Booth: Half-tiled booth combining reflective surfaces and heavy acoustic treatment. Distinctive evolving character - bright crisp peak with a hint of distant thunder. Compare with its warmer twin “Cognac Booth”.
• Vocal Booth: Heavily treated isolation booth. The thick carpet and absorbent walls produce the darkest, driest sound. Ideal for vocals or any performance that needs to speak for itself. An almost subliminal reverb brings it to life and makes it 3D.
• Walnut Room: Medium sized tracking room with solid hardwood surfaces and only minimal treatment. Distinctive warm tone and controlled reverberation.

6.1.2.2 Studios & Venues

• Bowery: Modelled on a world-famous venue in New York City that played a key role in the birth of punk rock. With its long, narrow shape and incredibly cramped stage, the audience themselves absorb any stray reflections. Dense and punchy.
• Congregational: Modelled on a well-known studio in a converted church in London. High ceilings and reflective surfaces are tamed by acoustic treatments. A large, versatile space with a sound combining a crisp immediate response with a subtly warmer decay.
• Kreuzberg: A medium sized hall with distinctive wooden surfaces generating a tangy and lasting reverberation. Based on a recital room in Berlin, later converted into a world-famous studio. A lively tracking space used for landmark rock recordings.
• Kreuzberg Recital: A medium sized hall with distinctive wooden surfaces. Based on a recital room in Berlin (later converted into a world-famous studio - see “Kreuzberg”), set up here for live performance with more balanced tone and distinctive spatial layout.
• LA Coffee: Based on a famed Los Angeles live music venue. A key site in the rise of folk-rock and Americana, it is surprisingly compact for its ~500 capacity. Its tone balances the effects of a packed audience (warm) and untreated wood (bright).
• Nashville A: Based on a well-known studio in Nashville, a large hall within a renovated church. It is a versatile, neutral sounding space used for pop-rock, country, and film productions when space for a full band, choir or orchestra is needed.
• Nashville B: A large tracking room based on a well-known recording studio in Nashville. Acoustic treatment gives the space a versatile, dense, tight sound with a fairly neutral tone, while still being large enough to accommodate a band or ensemble.
• Oxford Recital: Modelled on an eighteenth century recital room in Oxford. Purpose-built for chamber music, the elongated room has distinctive acoustics suited to expressive, sustained sounds. The stage provides space for a small ensemble.
• Pacific A: Modelled on a world-renowned studio in Hollywood that stamped its sound on America’s most influential hits from the late 1950s to today. Big enough to accommodate an orchestra, but with a controlled, versatile acoustic.
• Pacific B: Modelled on world-renowned studio in Hollywood. The smaller of two huge tracking rooms (“Pacific A” is its larger sibling). Acoustic treatment gives it a tight, neutral tone, suitable for a wide range of genres.
• Soho Jazz Club: Modelled on an iconic jazz club in London, this space has an unusual layout: a wide, low-ceilinged room with small stage set against one wall, surrounded by upholstered seating and tables. Subtle, intimate.
• St Johns Wood 1: Inspired by a world-famous recording studio in London, this high-ceilinged, hangar-sized room is big enough for an entire orchestra. The reverb is tamed by acoustic treatment which gives the space a controlled warmth.
• St Johns Wood 2: A large high-ceilinged room modelled on the dimensions of a world-famous recording studio in London. The reverberation is contained by acoustic treatment which gives the room a satisfyingly thick, warm sound.
• St Johns Wood 3: A fairly small, high-ceilinged room modelled on the dimensions of a world-famous recording studio in London. The relatively short dense reverb has a thickening effect and a certain warmth. Versatile.
• Van Nuys A: A mid-sized tracking room modelled on a famous recording studio in Los Angeles. The pleasing and versatile acoustics arise from the dimensions of the space and its reflective floor, while acoustic treatments keep the reverb time short.

6.1.2.3 The Works

• Drama Studio (In The Round): The soundstage is in the centre of this theatre space, surrounded by the audience area and beyond which are thick absorbent curtains. For such a large room it has a short reverb time and a pleasing warm tone.
• The Works - Bunker: Large untreated space with reflective surfaces of stone, concrete and brick for a dramatic cavernous industrial sound.
• The Works - Chancel: Large space with wide soundstage and thunderous reverberation. Mixed surfaces lead to a natural-sounding, evolving tone with a distinctive character.
• The Works - Clocktower: A tall room with a relatively modest floor area and reflective surfaces providing a bright tone with a manageable duration.
• The Works - Fluorescent Tube Booth: Unusual acoustic treatment gives this booth an emphasis on the high-mid frequencies. Edgy, exposed and unforgiving, but it may be just what you need.
• The Works - Foundry: An uncompromisingly long reverb from a room with stone floor and reflective surfaces. Initially bright with a long, gradually warming tail. Gravitas and grandeur.
• The Works - Hallway: A long, narrow space, carpeted but with no acoustic treatment. The soundstage is squeezed across the corridor. A natural, neutral tone and a useful short decay time.
• The Works - Pit: Superficially unglamorous rehearsal space whose tone seems to enhance the detail in a performance and brings it closer to the audience. An aural magnifying glass.
• The Works - Qube A: Small cubic rehearsal space. Pleasing neutral tone and controlled reverb.
• The Works - Qube B: Medium sized cubic rehearsal space. High ceiling, controlled reverb with a pleasing neutral tone.
• The Works - Qube C: Large cubic rehearsal space with a pleasingly natural live sound.
• The Works - Unit 1: Medium sized rehearsal space with a natural evolving tone and manageable reverb time.
• The Works - Unit 2: Medium sized rehearsal space with light acoustic treatment. Pleasing neutral tone and short reverb time.
• The Works - Unit 3: Medium sized rehearsal space with distinctive acoustics initially scooped but evolving toward a more neutral tone. Slightly uneven with a hint of slap-back echo.
• The Works - Workshop: Like its more intimate up-close cousin the Pit, this medium size rehearsal space has a pleasing natural tone that exposes the detail in a performance.

6.1.3 Trial Bundle

The Trial Bundle is a small selection of rooms included with the plugin, available in Trial Mode before activation. There are two rooms from each of our three curated bundles (described above):

From Studios & Venues: St Johns Wood 2 (the default room which is loaded with a fresh instance) and LA Coffee From Rooms & Booths: Pine Room and Vocal Booth From The Works: Foundry and Pit

6.2 Missing or Damaged Rooms

The room browser marks each room with a status dot, and unavailable rooms display an explanatory message in the details column. There are two distinct problems the plugin can detect:

• Missing: the room’s data file cannot be found on disk.
• Damaged: the file is present but its content does not pass integrity checks.

In both cases, if the room belongs to one of the included bundles, re-running the installer is likely to fix the issue - the installer replaces the included library files. Your license and settings are stored separately from the library and are not normally affected by reinstalling. Just in case, it is wise to make a note of your registered email address and license key before reinstalling (both can be found in the activation panel, or in your account at hartleydsp.com). The same advice applies when an entire included bundle is unavailable.

In our experience, the most common cause of missing or damaged rooms is manual changes to the library folder - files moved, renamed or edited outside the plugin. See “Changing the Library Location” below before reorganizing anything by hand.

6.3 Locked Rooms and Bundles

Rooms shown with a lock icon are present on disk but not available under the current license:

• Trial Mode: only the Trial Bundle is unlocked. The remaining included rooms are visible in the browser so you can see what the full version offers, but they cannot be loaded until you activate. See the Trial Mode section of this manual (or Help/Trial Mode in the plugin) for details.
• Not included in your license: the bundle is installed but your license does not include it (for example, an expansion bundle you have not purchased).
• Refresh required: your license may include the bundle, but the plugin has not yet verified access. Refresh your license: open Settings (the gear symbol in the header), choose “License…”, and click “Refresh license”. This briefly requires an internet connection. If a bundle you believe you own remains locked after refreshing, contact support@hartleydsp.com.

6.4 Expansions

Free and premium expansion bundles may be made available at hartleydsp.com. If you obtain an expansion, follow the instructions included with it to register and install the bundle, then refresh your license (as described above) so that the new rooms become available in the plugin.

6.5 Changing the Library Location

Advanced users can relocate the IR Library - for example to a larger drive. The “Change Library Path…” button at the bottom of the room browser changes the location where the plugin searches for the library. It does not move, copy or modify any files.

To relocate the library safely:

1. Close your DAW (or remove all THeVerb instances).
2. Copy the entire contents of the IR Library folder to the new location, keeping the folder structure intact. Copy rather than move, so the original remains as a fallback until you have confirmed the new location works.
3. Reopen the plugin, click “Change Library Path…”, and select the new folder.
4. Confirm in the room browser that all bundles and rooms show as available, and that rooms load and play correctly.
5. Only then, if you wish, remove the original folder.

The change applies to all instances of THeVerb on the machine. If the new location proves incorrect (for example, the browser shows “No bundles found”), use the same button to point back at a working copy - the default location is %appdata%\HartleyDSP\THeVerb\IRLibrary. Any unintended change to the structure or content of the library files and folders can cause rooms or bundles to become unavailable; re-running the installer restores the included bundles to the default location.

6.6 Unavailable Rooms in Saved Projects

If you open a DAW project that references a room which is currently unavailable - missing, damaged, or locked under the current license - the plugin loads a default room instead and posts a warning in the notification area, so your session keeps working.

The project’s original room selection is generally preserved: the plugin retains the original room reference, and saving the project keeps it, so the correct room returns once the library is repaired or your license refreshed and the project is reopened. The preserved reference is replaced only when you actively select a different room in that instance - at that point the plugin treats it as a deliberate new choice.