What is Algorithmic Reverb? How to Get Stylish Ambience in Your Mix

What is an Algorithmic Reverb Michael Gerzon M.R. Schroeder, Synthetic Stereo Reverberation.

For software users, reverb effects tend to fall into one of two categories: Algorithmic or Convolution based. Let’s take a deep dive and define them once and for all.

Algorithmic Reverb defined

An algorithmic reverb is based on a mathematical model that simulates the behavior of a physical space. You can think of this as a really complex signal chain. In an algorithmic reverb, your audio is passed through a network of digital delay lines that are modulated, filtered and fed back into each other in a manner aimed to resemble the reflections of a room, hall or chamber – or even a “super-natural” space.

Algorithmic reverbs - whether in VST plugin or hardware form - are hard to develop because they consist of so many parameters that each have compounding effects on the end result. One little change in any part of the chain/algorithm will make for a completely different sound, and things can quickly get metallic or murky. This means you need equal development and sound design skills to create a great algorithmic reverb. (And a whole lot of patience!).

Because of the complexity that goes into developing pro-grade algorithmic reverbs, these effects are often considered ‘the holy grail’ of DSP development. In audio circles, the inner workings of legendary algorithmic reverbs such as the Lexicon 480L have almost become as mythical as the Coca Cola recipe.

Algorithmic reverbs are not as realistic as convolution reverbs, but in some ways this is their strength. They turn the idea of what a “reverb” is on its head: Instead of aiming to sound exactly like the real world, algorithmic reverbs tend to just sound like reverb effects, often in ways that transcend the limitations of any natural space. This is why algorithmic reverbs are so great for making vocals, synths or mix busses sound larger than life.

At Baby Audio, we love algorithmic reverbs (perhaps you can tell). Our best attempt at making one for the modern era is our Crystalline plugin (VST, AU AAX + iOS). It stands on the shoulders of classic studio reverbs such as the Lexicon and EMT units that defined the sound of the 1980s, but offers an upgraded, contemporary sound and feature set.

Crystalline by Baby Audio, a modern algorithmic reverb.

Convolution Reverb defined

Convolution reverbs, on the other hand, use Impulse Responses recorded out in the real world to create a natural sounding reverberation. You can think of a convolution reverb as a plugin that can host ‘samples’ of real spaces and which lets you send your tracks through these space samples to get similar reflections (often with a very high degree of realism). The benefits to this approach is accuracy and its ability to mimic real world spaces, but the main drawback is that impulse responses tend to be somewhat static. (And sometimes, real world spaces just aren’t as exciting when you want to truly elevate a track).

Algorithmic Reverb vs. Convolution Reverb - what’s better?

If you make music firmly rooted in the real world, such as folk, classical or jazz, you’d probably want to find a well equipped convolution reverb. It will give you the truest representation of the rooms and halls known from our physical world and help your music sound natural and “real”.

On the other hand, if you’re looking for reverb as an ‘effect’ to elevate and enrich your tracks, then algorithmic reverbs tend to offer more potential – both sonically and feature-wise. Sonically, algorithmic reverbs aren’t tied to the constraints of the physical world. Their algorithms can be tweaked in endless ways to make super-natural spaces that give your music a touch of otherworldly magic. For this reason, algorithmic reverbs are typically preferred for modern music genres such as pop, hip hop, electronic, dance, ambient and experimental.

Having said that, algorithmic reverbs aren’t just for modern sound design purposes. If you’re looking for a 1980s or 1990s retro vibe, an algorithmic reverb is 100% the way to go! Especially in a lower quality setting such as Crystalline’s optional ‘basic’ mode.

What’s the history of the Algorithmic Reverb?

The idea of recreating a physical space digitally through an algorithm - or mathematical formula - was pioneered in the 1960s by academics such as Manfred Schroeder and Michael Gerzon. It may seem like an obvious idea today, but you have to remember that computers and microchips were almost as foreign at the time as the space rocket that landed the first human on the moon.

The space age was an era for big visions and small chips!

As a result, algorithmic reverbs improved slowly but consistently throughout the 20th century – with every new technology leap. Companies like EMT and Lexicon finally led the way in making algorithmic reverbs the go-to choices in studios around the world.

This leads us to Crystalline


With modern computer power at our disposal, we now have a luxury our predecessors could only have dreamed of. Where they had to walk a hard line between restraint and imagination, our super-powered computers allow us to focus primarily on the latter.

In working on Crystalline, we experimented with the algorithmic reverb concepts originally envisioned by pioneers like Gerzon and Schroeder — and re-applied their ideas from scratch without the original limitations. This led to A LOT of delay lines! And even more trial and error.

But in the end we got something we're proud of as a contribution to the ongoing evolution of the algorithmic reverb. Crystalline is certainly not the end station, neither is it the only modern reverb to tap into these classic ideas. But it offers our upgraded and genuine take on what could rightly be called ‘the holy grail’ of dsp – designed with a 21st century user in mind.

If you want to hear Crystalline in action, you can get a free trial and learn more by clicking the link below.

How to use algorithmic reverb in your mix

Algorithmic reverb is perfect for any situation that calls for stylish and creative atmospheres.

It’s often used for large ambient washes where modulation plays a central role. But it works equally well for applications that require tight rooms, plates and chambers.

Many of the most beloved algorithmic reverb hardware units are famous for their non-linear modes, including the classic gated reverb trick from the 80s.

Crystalline can add a distinctive flavor whether you need the expansive sound of a space that’s larger than life, or a short decay that stands out with rich character.

Here are a few tips for using algorithmic reverb with Crystalline:

  • Engage slow, deep modulation on settings with long decay times to add lushness and complexity to the reverb tail.

  • Shape the harmonic content by adjusting the high and low damping frequencies. Try different combinations with short or long decays to see how they interact.

  • Create the classic gated effect by turning up the gate control’s threshold and setting the release to match the song’s tempo.

  • Try the Shimmer function to add a ghostly upper octave reverberation to the signal

Crystalline: Not Your Grandfather's Reverb

Written for Baby Audio by James Kelly, Member of the Recording Academy, GRAMMYÂź Voter.

I have to admit: reverb plugins often elude me. Despite a Latin Grammy nomination as an engineer, I'd be lying if I said every time I load up a reverb emulation I immediately feel at home. What's this parameter mean? How do I make my reflections brighter? What's a bass multiplier? And on and on.

But, I'm pleased to report, Baby Audio's Crystalline is the rare exception. Here you'll find an incredibly user-friendly reverb plugin that combines all the production-and-mix-ready features that it often takes several other plugins to handle. And, most importantly, it sounds great.

Before I dive into its applications, let's just talk about the features. Yes, you'll find all the parameters one typically associates with a reverb plugin: the size of the reverberant space, the stereo width of the reflections, the trusty dry/wet slider. But there's so much more: an extremely useful built-in ducker, an exceedingly fun Freeze button (which holds the reverb till what seems like infinity), and—wait for it—an entire Clean Up section that actually makes crafting the sonic makeup of your reverb intuitive. Hell, you can even augment the fidelity of your reflections—from something approaching 16-bit glory on up to pristine modeling of each lush bounce.

Now let's talk use cases. I started by loading up an edgy synth bass line in need of some character. Before touching a preset, I set out on my own to find a sound. After dialing in a short, wide verb, I ventured into Crystalline's more exotic parameters. First, I cranked the Modulation all the way up: what was once a relatively subdued reverb became a swirling, snarling beast. Next, I turned to the Smoothing parameter in the Shape section. The on-screen helper text (which is very helpful) informed me that this parameter attenuates "sharp" frequencies in the reverb. Looking for even more aggression, I pulled that parameter all the way down, letting the bite of the reflections punch through. Presto: my boring synth bass had been given a brooding, breathing, foreboding vibe.

Crystalline by Baby Audio, a modern algorithmic reverb.

Turning my attention to drums, I loaded an instantiation of Crystalline onto a track containing a hip 80s drum machine loop. At this point, the plugin's wide array of presets were calling to me. Scrolling through the Drums list (the presets are broken down by instrument and by sound designer), I immediately spotted one to which I could not say no: "DO YOU LIKE PHIL COLLINS." Hell yes I do! The result? Instant gated verb heaven. The reflections were tight and crisp with a warmth and character often lacking from 80s-inspired verb engines. By engaging the plugin's Reverse button (which many verb plugins sadly lack), a relatively tame beat became a shimmying, polyrhythmic banger. 

Lastly, I had to try this awesome thing on humans. I loaded up a dry sample of a lilting soprano vocal and let Crystalline do its thing. Again, I turned to a preset to start. This time it was Dean Reid's "WEIRD VOCAL DELAY." Off the bat, this preset delivered an enchanting personality to the vocal. I can only describe it as a delicate, bright verb that ends in a hint of pitch-decay delay. Really intriguing. By increasing the width of the verb, the vocalist began to swirl around my head. Reducing the size of the reverberant space and pulling out some high end made the vocal incredibly intimate while still providing the space needed to make it sound like a polished performance. 

What a rush. Crystalline is easily the most flexible, intuitive, and fun reverb plugin I can ever remember using. It looks and sounds great and has immense promise as both a production and sound-design tool. It has instantly found its way into my sonic arsenal. Try it for yourself and see: what's now boring can be exciting; what's now static can be given life.

Get your free trial of Crystalline by clicking the link below.

Crystalline 1.3 Out Now

Crystalline updated to 1.3

The new update includes bug fixes, improvements and a new/revamped feature:

  • Preset library updated to organize by purpose/instrument as requested by many users.

  • "Crackling bug" fixed in the Transients feature. Now replaced with an improved and new parameter called "Warp", which lets you shape how the reverb responds to transients – and shift the emphasis toward attack or release.

  • Improved reverse function.

  • Various graphical and performance updates.

The new 1.3 update is free for all owners of Crystalline. We hope you’ll enjoy it!

 

Splice Rent-To-Own Launch

Get harder mixes for the price of a coffee

We've teamed up with Splice to offer our latest plugin IHNY-2 via their popular Rent-To-Own model. This means you can get one of the hardest hitting compressors in the industry for the price of $4.99 per month – for 14 months.

It's like an extra cappuccino each month, except this one has triple-shot strength and will make your drums slap harder than ever!

What we like about Splice's RTO model is that you actually get to own the plugin in the end. So it's not like a subscription that ties you in with no end-date – and leaves you with nothing when it's over.

And if you decide IHNY-2 is not for you, you can of course cancel anytime.

We think the RTO model is probably the most fair way to get plugins at a low monthly cost, and our users have been asking us for such an option. So we're beyond excited to have joined forces with Splice. With a bit of luck more of our products will launch there soon as well.

Grab IHNY-2 now to get your mixes hitting harder!

Magic Switch: Free Chorus VST Plugin

To get Magic Switch for free, head to our Freebies Section.

 
Baby Audio Magic Switch Best Free Chorus Plugin
 

What is Baby Audio’s Magic Switch?

Magic Switch is a free VST, AU and AAX chorus plugin for Mac and PC, developed by Baby Audio. It’s based on the “Magic” parameter in our award-winning Super VHS plugin. Magic Switch strips the Super VHS “Magic” feature into its own free plugin to give you instant, dreamy 1980s Juno Chorus vibes.

In the below we’ll go through some of the typical questions about chorus effects to get you more familiar with Magic Switch.

What is a chorus effect in music?

Chorus is one of the original cheat codes for making music sound thicker and richer. In fact, it goes all the way back to the classical ages. The effect occurs when the same sound is played back in multiple “instances” that each have slightly different time and pitch variations. Imagine a string ensemble: Each musician could play the same notes, but it would be virtually impossible for their timing and pitch to be 100% identical all the time. The resulting pitch/time variations are perceived by our human ears as making the music sound richer and deeper. (And quite frankly it is as there’s more information for our ears to process).

The metaphor of the ‘string ensemble’ is actually not so far off when we talk electronic chorus effects. In Korg’s Polysix synthesizer, the built-in chorus option is simply called “Ensemble”.

What is a chorus plugin?

A chorus effect, whether in plugin, pedal or hardware form is an attempt to simulate the ensemble effect of several musicians playing the same notes with subtle variations. This is done by taking a signal and mixing it with one or more copies of itself, which differ in pitch and time. Typically, these differences will be created by an LFO that modulates the copies relative to the original audio source.

A stereo chorus keeps the pitch and time differences separated between the left and right channel. This makes the stereo image feel wide and magical. Magic Switch does this quite well (hence the name).

The chorus FX parameters explained:

All chorus effects will share some of the same parameters, but there’s a difference in whether or not these parameters are exposed to the user. In the case of Magic Switch, we’ve set the parameters exactly how we feel they need to be to give you that wide and dreamy 1980s sound with the click of a button. You could call this a curated approach.

On the other hand, if you’re using stock audio plugins, you’ll probably be given a bunch of parameters to play around with yourself. These are going to vary from plugin to plugin and DAW to DAW – but let’s explore some of the most common features:

  • Rate / Speed: This sets the frequency of the low frequency oscillator that’s modulating the signal to create a chorus effect. It sounds a bit complicated, but think of it as the speed at which things go in and out of pitch. For a dreamy effect, you might want something slower and more subtle. A higher rate will sound dizzier, which can work well for more radical sound design.

  • Depth / Intensity: Controls the frequency range of the pitch modulation created by the chorus effect. Or in simpler words, this feature sets how much ‘out of tune’ your chorused signal is going to get when it goes out of tune. (It does, remember that’s what a chorus is).

  • Width: Controls the chorus width from mono to stereo or anywhere in between.

  • Feedback: This is a less common parameter in chorus VSTs, but you’ll sometimes find it in better equipped plugins. It adds a chorus signal back into itself in a feedback loop. This can give you some very intense sounds if that’s your thing.

  • Dry / Wet: Use this control if you want less of the chorus effect blended in with your dry original. In Magic Switch, this parameter is useful as the effect can be quite colorful otherwise.

What is a Juno Chorus?

The “Juno Chorus” refers to the on-board chorus effect in Roland’s Juno-series of synthesizers from the 1980s (such as the Juno-106 and Juno-60). The Juno Chorus was a one-button chorus effect that could only be either engaged or disengaged, but not fine-tuned by the user. (Hint: It was usually engaged!). To give some variation, Roland equipped the Junos with two effects, chorus 1 and 2, which offered different levels of intensity.

The Juno Chorus was created by a set of Bucket Brigade Delays (BBD), which gave it its distinct analog character. We’ll explain this concept another time as it almost warrants its own blog post.

So what’s so magical about the Juno Chorus?

Well, frankly, it was just incredibly well tuned by the legendary company that had already developed the famous Dimension D and Boss CE-2 chorus effects. The Juno Chorus was engineered by Roland - to perfection - to complement the character of the Junos’ Saw and Square oscillators. As with anything in audio, it’s all about doing things that vibe with each other, and the Juno Chorus vibed with the synth that hosted it in a way that almost ended up defining the sound of an era.

In fact, we’d argue that the Juno Chorus was as much an achievement by Roland in sound design as in engineering. This is what inspired us to create our own ‘sound design engineered’ one-button chorus effect in the form of Magic Switch.

Magic Switch is not meant to be a Juno chorus emulation. Instead, it’s meant to be an ideal chorus effect for this day and age of digital music production – where tracks are cleaner than ever and often in need of some character and soul. As a result, you’ll find Magic Switch to be darker and more detuned than the Juno Chorus. This is how we think a one-button chorus VST should sound today!

The one and only Juno-106. Some people say it’s not as ‘meaty’ in the low-end as the Juno-6 or Juno-60 – but to our ears it’s synth perfection.

Is Magic Switch the best free chorus plugin?

Magic Switch is our best attempt at designing the perfect free chorus plugin. One that’s simple enough to not obstruct your workflow – and lush enough to elevate your tracks. Why don’t you try it out and see how you like it? It’ll cost you absolutely nothing!

Written by Baby Audio founder Caspar Bock.

Update May 2023. Thanks to Bedroom Producer’s Blog for naming Magic Switch among the best free chorus plugins: LINK

Crystalline iOS Released

iOS AUv3 Best Reverb Plugin Baby Audio Crystalline

Get Crystalline for your iPad/iPhone

Algorithmic reverbs have come a long way! Studio owners in the 1980s would routinely pay tens of thousands of dollars to get digital reverb systems with limited flexibility and imperfect sound.

Today, you can have a more versatile reverb, with crystal clean definition, inside your phone. All for the price of a round of beers.

So if you like the idea of walking around with a professional grade studio in your pocket, you might want to add this one to your arsenal.

Crystalline iOS - out today - is the App version of our premium reverb plugin, for iPad and iPhone devices. It's compatible with all major AUv3 plugin hosts.

Go grab it on the App Store for just $29.99: LINK

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Baby Audio M1 Update

Baby Audio M1 - All Plugins Are Compatible

Our plugins are now fully M1 compatible

We're happy to share that we've updated our full suite of plugins for Mac M1 Native compatibility.

If you're on a new Mac, this should make a great impact on CPU performance. And even if you're not, the updates still offer a number of minor tweaks that you'll benefit from. So we recommend you go grab them!

You can update your owned plugins by following the download instructions in your original order email – or head to our Free Trials section to get a demo of any plugin you don’t own yet.

The update is free for any plugins you already own.

We hope you'll enjoy the improvements! Let us know if you experience any issues.

 

The ‘Mac vs PC’ of Plugin Design

This is the first in a new series of articles about our approach to plugin development, written by Baby Audio founder Caspar Bock.

ï»żI was recently writing back to a beta tester about a forthcoming plugin. He’d asked me why we chose to hide certain parameters under the hood instead of making them user-controllable – and that’s where the idea for this blog post came up.

We’re often asked about our approach to vst plugin development. We’ve also been asked why our blog is so rarely updated.

The purpose of this forthcoming series of posts is to address both issues!

OK, so back to the beta tester


He was asking a very reasonable question: Why not give users access to certain parameters that are already in the plugin but hard-coded under the hood?

In coming up with an answer, I thought about the two classic ‘religions’ of personal computing, Mac vs PC. PCs were historically about interconnectivity, modularity and full user customization, whereas Macs had a curated and self-contained nature.

The Mac philosophy was to make systems that were close-ended and 'guardrailed', giving users a smaller space to operate within, but one that was thought-through from A-Z. You couldn't do as much on a Mac, but you also couldn't really screw things up. This suited some users as they could worry less about the tech and more about their actual work. Other users disliked the limitations and opted for the customizable nature of the PC.

Both schools have their pros and cons


And on a personal level, I've never really been too devoted either way.
However, when it comes to making audio plugins, I've realized that we are more Mac than PC at Baby Audio. Not deliberately, but I can see it looking back (and forward) on our design decisions. We like the idea that you can abuse all the parameters in our products without seriously damaging your output. We like that our plugins offer a sonic experience that is curated and consistent regardless of what you throw at them. We think that intelligently planned guardrails can give the product experience a sense reliability and instil confidence in the user. (And who doesn’t want that from a plugin).

And that’s why we hide certain things


Some parameters would change the sound too much. Others would clutter the interface and make the music production workflow less intuitive. We don’t want that. So we hard code these parameters under the hood, either statically or dynamically. Leaving the user with just enough flexibility to do something unique and personal but never so much that it overwhelms the creative process.

This will upset some and inspire others


And that’s exactly how it should be!

Ultimately, the Mac vs PC rivalry benefitted both platforms. And if I look around at the audio plugin landscape, there’s plenty of options for every preference. Some rivalry between us developers is only interesting, and in fact I wonder if there could be even more of it sometimes?