SparkVerb's main window offers a frequency graph from left to right, above which hovers a cloud of colours. These colours indicate the active areas of the frequency spectrum and how those areas will generate reverb once a sound has been routed into the plug-in. Beneath the display, SparkVerb gives you access to three frequency bands and controls to determine their decay speed. The prominent, central dial is simply labelled Decay, while Hi Decay and Lo Decay lie on either side. These provide independent speed control over the rate of reverberation fade of higher and lower frequencies. You can choose the crossover frequency between the bands, or employ high or low shelf filters to remove these outer bands from processing altogether. Above, the colour palette changes, providing attractive and immediate visual feedback.
To the left, you can then pick size and shape for the virtual space you're creating, as well as introduce modulation to create deliberate artefacts and moving components within the reverb decay tail. Three algorithms are offered—Lo-Fi, Bright and Dark—and coupled with Depth and Modulation Rate dials, you can introduce pitch, brightness or noise-based modulation of the reverb to enrich the ambience further. Over on the right, you'll find more conventional parameters. There's a dial that controls an overall mix, as well as a rolloff control, which provides a low-pass filter over the entire reverb signal if you want to pare back an over-bright top-end. The Width control allows you to move between narrow, focused reverbs and wide-screen ones. There are also sections for diffusion and density.
As you should be able to tell from this extended parameter set, SparkVerb is ready to respond, irrespective of your reverb needs. If you need conventional settings like drum ambience, or a short, plate-like setting for vocal placement, you'll certainly find what you need. And more leftfield, out-there reverbs, which allow you to suck snares into a deep hole, or push claps up into the treble ether with no bottom-end in the reverb, are just as achievable. However, if you want to let fate decide how your reverb parameters will be configured, a dice icon in the top right-hand corner randomizes all settings, though you can individually lock any parameters if they're already set to your taste. A simple control-click (on a Mac) activates a drop-down menu, which then launches a clearly visible padlock icon next to parameters when activated.
Using SparkVerb as a playground of sonic possibility stretches way beyond randomization of parameters. An icon that looks like a grid of interconnected dots launches the Preset Voyager, which is every bit as space-aged as its name suggests. A menu down the left side of this window organizes presets into categories, with red-coloured presets representing halls, green ones providing vocal treatments and so on. The specific presets within these categories are then spread across a constellation to the right, with each snapshot setting resembling a star. Any suggestion of style over substance is quickly erased when you realise it's possible to morph between settings of these adjacent stars, with the result changing accordingly.
Here's how it works: let's say you click on the star called Drum Room, which offers a preset for a punchy drum or percussion part. There are a number of other stars around this one, and as you hover your mouse over them, SparkVerb shows you the names of these adjacent settings. Some of these form obvious relationships, others more leftfield ones. If you then click on a star and drag in the direction of another, the parameter dials begin to spin, morphing the settings from one to another. However, these relationships are actually formed between three stars, so if you draw a straight line between two, these will form the majority of the parameter relationship. But if you allow your mouse to drift towards a third star, it will influence the resulting parameters, too. It's hugely intuitive and yields wonderful results and unexpected sonic treatments. Indeed, this is a fair summary of SparkVerb overall. If you have a clear idea of the reverb treatment you want, you'll be able to build it quickly. However, if you want to explore unexpected and unique sonic treatments, SparkVerb is more than happy to act as your guide.
Ease of use: 4.5/5