In this final part of the Orchestral Positioning series of articles, we’ll be looking at different reverb types and stereo processing techniques, plus some reverb plugin recommendations.
To convo or to algo
There are two main types of reverb: algorithmic and convolution. In a nutshell, algorithmic reverbs use a mathematical formula — an algorithm — to calculate and simulate how sound behaves in a virtual space defined by a set of parameters. Convolution reverbs on the other hand rely on impulse responses which are recorded snapshots of real spaces or hardware reverbs. The IR’s are added to the input signal through a process called convolution, effectively creating the illusion that the signal was recorded in — or, in the case of hardware, through — the source of the IR.
There’s a lot of discussions on the web on the matter of which type is superior, but if you look beyond all the marketing hype and the comments from people who have bought into it, one thing becomes clear: both have their pros and cons and they’re not mutually exclusive. It all comes down to taste and application.
Personally I prefer algorithmic reverbs, mainly because of their flexibility. They will let you set and fine-tune every part of the reverb sound. They’re also often spacier and more “live”-sounding than convo verbs. Set up right, they will give you a nice airiness that is hard to capture with a convo verb. It’s comparable to the bloom/HDR lighting effect in 3D graphics; it’s nothing you would actually see in reality, but it softens the digital harshness and adds a nice aesthetic touch.
As for convolution reverbs, they certainly have their uses. My main gripe is that their sound and quality wholly depends on what impulse responses you have at your disposal. Another problem is that if you have lots of IR’s, finding one that suits the project at hand can be a very time-consuming, boring and potentially even futile task. Thirdly, convo verbs tend to have a slightly dead-sounding response, as they are after all based on a moment frozen in time rather than something that dynamically responds to the input signal. On the upside, convo verbs give you access to hardware that most of us can only dream of ever affording. Plus that they can’t be beat for realism, if that is what you’re after and you have some nice IR’s of real spaces.
So in short, if you’re new to all this I would recommend starting with a good algorithmic reverb. Working with it will teach you a lot about how reverb works, which is valuable knowledge when it comes to working in this reverb-laden genre of music. If you on the other hand think convolution reverb sounds like your type of thing, be prepared to part with money right off the bat as 1) there are no really good free convo verbs, and 2) there’s not a whole lot of free IR’s with the right qualifications. Which brings us to:
Reverbs and stereo processing
Sound quality is not the only factor to take into account when choosing a reverb for orchestral music. Different reverbs use different stereo processing techniques which will make a significant difference in believability. Not even the smoothest, lushest reverb in the world will do you much good if it messes up your instrument positioning and generally sounds like a thick mush.
The three most common processing techniques are mono-to-stereo, parallell stereo, and true stereo. While it’s not always as clear-cut as that (e.g. some reverbs will use true or parallel stereo early reflections but mono-to-stereo late reflections), generally speaking most reverbs will fall into one of the three categories. Let’s take a look at how these three techniques work.
A mono-to-stereo reverb takes the left and right input and sums them to mono before feeding the signal through the reverb algorithm. Out the other end comes a wet signal in stereo, but because of the mono summing everything will be centered in the stereo image. No matter how you pan your instruments, the reverberations will stay firmly centered, even if there’s stereo separation between the left and right channels. This is of course a bad thing in a virtual orchestration where it’s vital that an instrument’s position in the virtual space remains unambigous.
Parallell Stereo (PS)
A parallell stereo reverb processes the left and right channels independently, each one in mono. This is a slightly more natural-sounding technique than M2S, though not quite as good as true stereo. The farther you pan something to the side, the more attenuated the reverberations in the opposite channel will become. Beyond a certain point they will go completely silent. Meaning, if you have an instrument panned way off to the left, you will only hear the reverb in the left channel. Obviously this is not how a real space behaves. Even if a player is positioned far off to your left, you will always hear sound waves being reflected off of the wall to your right.
True Stereo (TS)
A true stereo reverb works kind of like a PS reverb, the difference being that it processes each input channel in stereo. You could think of it as two PS reverbs running in parallell. With a TS reverb you can pan a signal all the way from left to right and hear the reverberations realistically follow the movement. As you probably have guessed, a true stereo reverb is highly preferable when working on orchestral music. It just sounds so much more spacious and natural than the other techniques that once you try a good TS reverb and hear the difference, you will never want to go back to using a M2S or PS reverb.
If you’re doing mainly orchestral music, your arsenal should at the very least contain one good true stereo hall reverb. Whether algorithmic or convolution, realistic or nonrealistic — it’s up to you. But good halls is an absolute must. No, a plate reverb will not do. Neither will a spring reverb or a room ambience generator. If your reverb has multiple algos/IR’s and can do all the other stuff as well, that’s great. But remember, your main criteria for choosing an orchestral verb should be the quality of its halls and nothing else.
Of course, hardly anyone these days uses only one single reverb. Like all audio plugins they all have different strenghts and weaknesses and having a couple of different reverbs to choose from is never a bad thing. But don’t overdo it. Unless you’re working in many and radically different genres, having more than two or — at the most — three different reverbs is probably a bad idea.
Limiting yourself this way might sound dumb considering there are like a hundred completely free reverbs available, but trust me, there is really a limit to how many you can have a use for. If you have 20 different reverbs (or compressors, or amp sims, or… ) you will spend more time switching between plugins than making music. Don’t get me wrong, I absolutely encourage you to try everything you can get your hands on. By all means, download every freebie you can find and demos of a bunch of commercial ones too. If nothing else, this is an excellent way of learning what a good reverb sounds like.
But in the end, your goal should be to find a couple of verbs you really like and then throw all the other ones out. No, just not using them is not good enough. As long as they’re in your VST folder they will continue to distract you and lure you into reconsidering them, even if you have determined several times already that they’re crap. Just delete them and don’t look back. Life’s too short to spend hours and days sorting through the same junk over and over again for no other reason than that you think you might have been mistaken the first three times.
Below is a small list of reverbs that I consider worth a look. I have chosen to list only freeware and inexpensive plugins because this guide is aimed at those who, like myself, don’t have a large budget for music. But even if you happen have big bucks to spend, don’t be too quick to shrug the more inexpensive offerings off. In the world of VST plugins, “you get what you pay for” is surprisingly seldom a valid rule of thumb.
Hibiki is a fairly new addition to the Freeverb3 family of plugins. It’s a modulating reverb with a lush, smooth Lexicon-style sound and plenty of tweaking options. The only real downsides are the 1995-looking UI, some enigmatic parameters, and the confusing Freeverb3 distribution model with multiple packages for different uses and processor architectures. For orchestral stuff this would be my first candidate in the freeware realm.
Sanford Reverb is a discontinued commercial plugin that was updated to x64 and re-released as freeware in 2015. I actually bought this reverb years ago and used it on a lot of older projects, but it kind of fell by the wayside when I moved to a 64-bit setup. It’s a transparent-sounding reverb and not my first choice for cinematic epicness, but for more subtle duites it’s wonderful. Easy to work with, very versatile, and very forgiving — it’s almost impossible to make it sound bad.
Before Hibiki came out, KR-Reverb FS was my favorite TS freebie. It’s a bit bare-bones and not entirely intuitive to work with (tread carefully or it will turn into a barrage of delay lines) but it does sound quite nice with the right settings. It has a lot of character, in a good way. Its coolest feature is the listener position parameter — great for quickly creating different front-to-back reverb busses. It lacks a predelay parameter though, so you need to use a basic delay plugin before it in the signal chain.
Tila2 and Abstract Chamber are two gems from Finnish developer signaldust. Tila2 is not technically a reverb per se, it’s a room modeller. But as it allows you to create fairly large spaces, you could use it to create an overall stage ambience for your orchestra, and then add a touch of its cousin Abstract Chamber for those nice bloomy tails (AC isn’t true stereo so I wouldn’t recommend using it all on its own, but YMMV).
There is no shortage of totally awesome free synths, compressors, EQ’s and even amp sims that will give their commercial counterparts a run for their money, but sadly free reverbs are lagging behind. As of this writing there is not a single free reverb I would choose over the ones listed below.
The best reverbs you can get for a modest amount of money is without a doubt ValhallaDSP’s wonderful ValhallaRoom and ValhallaVintageVerb. At a measly $50 a piece they rival many expensive software reverbs out there. They sport a whole bunch of different reverb algorithms and plenty of tweakability, so make sure to RTFM to get the most out of them. They can do anything from realistic rooms and halls to plates and murky vintage digital reverbs. Heck, just buy ’em. Either, or both. At that price point you just can’t go wrong.
The algos used in Eos were created by ValhallaDSP developer Sean Costello, and just like Sean’s own plugins it does not fail to deliver. The Superhall algorithm is lovely and even though it may be more aimed at ambient soundscapes and massive synth pads rather than orchestral halls, who’s to say that is not exactly what your orchestral mix needs?
Reverberate is a very advanced and configurable convolution reverb. It tries (and succeeds, to an impressive extent) moving beyond the staticness of convolution by adding modulation, dynamic filtering and delays to the impulse responses. You can even use two IR’s in sequence or parallell, generate your own IR’s based on different parameters, and much more. Overall a great convo reverb that lets you be really creative with your IR’s. Paradoxically, the extreme tweakability is also Reverberate’s only real weakness — it’s easy getting lost in all its settings and interacting parameters.
Breeze is the little brother of 2C’s flagship Aether reverb. I have demoed both on a couple of occasions, and to me Breeze seems more appealing both in terms of pricing and usability. Both reverbs sound equally incredible, but Breeze is easier to work with. OTOH, if you have the prerequisite money, time and patience, Aether offers some serious reverb nerd porn.
I’ve demoed Redline Reverb a couple of times and liked it a lot, even though I didn’t end up buying it. Just like Hibiki and ValhallaVintageVerb it’s a classic Lexi-style reverb with a big, lush sound.
I wasn’t aware of NI’s Lexicon 480 clone RC 48 until just recently (again, as of this writing), and tried the demo out of curiosity. The price tag and the fact that it has only two algos makes it feel like kind of a pricey one trick pony. But it also sounds really great so if you’re in the market for a no-frills hall reverb, you should definitely give this one a try.