A Reverb Built Around Mic Technique: André de Brito on ADB Room Mics

The initial idea was to model a simple drum room and experiment with different microphone techniques, using Steven Slate Drums as the starting point. The first versions had a drum kit in a fixed position, and you could only move the microphones closer or further away.

From there I gradually expanded the plugin. The microphone approach stayed central because it gives you a recording engineer’s way of thinking: where would I place the microphones, and how would I capture this room? Size and decay still matter, but the microphone technique and position give you another way to shape the sound.

The model also accounts for instrument directivity: how an instrument radiates sound in different directions. You can switch that off and use an omnidirectional source if you want to keep the original source. For a more neutral microphone perspective, you can choose a mono omni or an AB pair with the Neutral mic type.

AB would be a starting point for a spacious image, XY for a more focused image with good mono compatibility, Blumlein when the room itself is an important part of the recording, and ORTF for a balance of width and definition.

The same principles apply inside the plugin, but you don’t have to match the technique used in the original recording. If something was recorded with ORTF, for example, you can still use AB as your virtual room pair. You’re choosing how to capture the added room around that recording.

With an existing stereo recording, I would preserve its image using the Stereo source option, then choose the virtual microphones according to what the mix needs. I would also consider how much room is already present: a dry recording gives you more freedom, whereas a naturally ambient recording may need only a subtle addition.

Ears changes the perspective from microphones capturing a room to a listener being inside it. It uses measured KEMAR head-related transfer functions to represent how the head and ears affect sounds arriving from different directions.

The differences include timing, level and frequency response. On headphones, those cues can give a stronger impression of being in the space.

It would not be my automatic choice for every mix. The effect depends on the listener and the playback system, and a conventional pair may give a more suitable image when working mainly for loudspeakers. Ears is another listening perspective rather than an upgrade over all the microphone techniques.

The venues weren’t captured by me on location. I used published acoustic measurements, along with documented dimensions and materials where available, to recreate real spaces within my model. The calculated decay and other relevant information is checked against the measured data across frequency, rather than relying on a single reverberation-time value. If a room doesn’t meet the validation criteria, it isn’t included in the plugin.

I kept adding information and drastically improving the plugin on every release, and now it’s quite complex but still easy to use. You can choose different shapes of room, control early reflections and, of course, change the materials inside the room. It can be an extremely creative tool. There are over 300 presets to choose from as well, if you don’t want to dabble with all the parameters.

So it isn’t strictly a measured-versus-algorithmic distinction. ADB Room Mics generates its responses computationally, but the models of real spaces are informed by actual measurements. Those measurements provide a reference for the behaviour of a particular venue, while the model still allows you to move the source and microphones.

A measured space isn’t automatically better sounding. What is interesting is its particular acoustic character, including how different frequencies decay, rather than simply a generic “large hall” sound. The aim is to recreate those characteristics without claiming that every detail of the original venue has been reproduced.

I also expanded the creative side of the plugin, drawing on both acoustics and music production. I added gated and reverse reverb, ducking and modulation, alongside more unusual options such as coupled rooms, placing one room inside another, and combining the early reflections of one room with the reverberation tail of another. That lets you start with a physically grounded space and then take it somewhere more experimental.

I think people often underestimate how much the room affects both recording and listening. Even without an obvious reverb tail, early reflections and room modes can strongly colour what you hear. At low frequencies, those modes create peaks and dips that depend on where the source and listener are positioned.

Speaker placement and the listening position are particularly important. I’ve seen setups with the listener right in the middle of the room, which can be a problematic position because of deep modal cancellations. You might then try to correct a lack of bass in the mix when the problem is actually where you’re sitting.

There is also a tendency to think acoustic treatment is unnecessary, or that a few (or a lot of) thin foam panels will solve everything. Appropriate treatment matters, particularly for controlling low-frequency problems.

With a clean, dry recording, ADB Room Mics can add space, depth and a shared acoustic setting for separately recorded instruments. But it cannot remove the room already captured in a recording, or fix the acoustics of your listening environment. Good placement and suitable treatment remain the foundation for making reliable recording and mixing decisions.

There isn’t one single signing cost covering all of those. Windows and macOS have different code-signing and distribution processes, while AAX is a plugin format with its own requirements. ADB Room Mics doesn’t currently include a native AAX version.

I haven’t paid for all those processes myself, so I wouldn’t want to give an inaccurate total. My own decision was that, having already invested countless hours in development and testing, I didn’t want to take on additional signing expenses for a project I’m giving away.

For freeware developers, there is no income from sales to cover those expenses. I want to keep ADB Room Mics free, and donations help support its continued development.

I’m working on two more personal projects, due to sheer necessity, which will be out soon.

ADB Vocal Align came from my recent transition from Cubase to REAPER. I record a lot of vocal takes and harmonies, and I liked how simple Cubase’s Audio Alignment tool is. I wanted a similarly straightforward workflow in REAPER: select a reference and the takes to align, then do it directly within the session, non-destructively. The aim is to reduce repetitive editing while keeping control over the performance.

ADB Smart EQ is aimed at transparent correction for vocals, instruments, buses and full mixes, in both mixing and mastering. I’m developing an integrated adaptive engine that combines resonance control, broader tonal balancing and the management of harshness, continuously analysing the audio without a separate learning step. So instead of using different EQ tools, I can use just one tool for transparent EQ and another tool for analog EQ.

It will also include a manual parametric EQ with a live spectrum and a separate display of the correction being applied. The priority is maximum audio quality while preserving the source’s character, transients and dynamics.

I don’t intend to become a full-time programmer. These are personal projects, born out of things I need in my own music production, that I’ve decided to share with other musicians and engineers. Both are intended to be freeware with no obligations from my side. Donations are always welcome.