ACUSTICA AUDIO NEBULA 4
After almost a decade, this convolution multieffects processor makes its third full update, but is that hefty hard disk footprint still worth it?
It’s been almost a decade since we last had Acustica Audio’s much-loved Nebula multieffects processor plugin (VST/AU/AAX) on the test bench (Nebula 3: 9/10, 115), and much has changed since then in terms of both the developer’s own technical capabilities and the music software landscape in general. Released at the tail end of last year, Nebula 4 might not look like a massive upgrade over its predecessor, but a lot of changes have been made under the hood, not least the step up to Acustica’s CORE9 audio engine. It’s also been given a visual makeover, and now boasts a cleaner faux-metallic look, with an ever-present top bar housing input and output meters, and the editor and preset controls appearing below.
Installation is a faff, with a ton of zip files containing a ton of installers, so you can decide which of the included effects categories and plugin formats you want to put on your system. With the full collection adding up to around 10GB, we certainly appreciate the option to pick and choose, but we’re not sure why the whole thing can’t be bundled into a single installer.
On impulse
Nebula is a convolution processor, which means – in the simplest terms, as Acustica’s take on convolution goes way beyond the fundamentals – that it uses captured samples (called impulse responses) of real hardware effects units (a roster of unspecified-for-legal-reasons classics) to apply perfect emulations to the input signal.
The advantage of convolution over algorithmic systems is simply the realism and quality of the sound. Theoretically, a drum track pushed through a convolved Manley EQ will sound exactly the same as if it were hitting the real thing. The main disadvantage is that only the state of the hardware at the point of sampling is captured, so our hypothetical convolved Manley is stuck at whatever settings the hardware happened to be set to when sampled. The solution, then, is to capture multiple impulse responses and interpolate between them in real time, which is what Nebula does, enabling a degree of control over each of its emulations that – while nowhere near that of an algorithmic effect – is enough to get the specific job for which that emulation was designed done.
For example, a given EQ preset might comprise a single parametric band, or a set of fixed bands with adjustable gain; while each N4 reverb preset gives you a fixed reverb sound (a short plate, a long hall, etc) with adjustment of nothing more than dry and wet mix levels.
And that’s why the impulse response library is so big, at over 450 sample-powered presets: just as each captured reverb algorithm is a preset unto itself, so is each band of a threeband EQ, each mode and pole configuration of a filter, etc. It’s an approach that takes a bit of getting used to, but as its legion of fans will
attest, the payback in terms of sound quality and ‘hardware realism’ is more than worth the arguable inconvenience.
New in N4
Although the most profound improvements made to Nebula for v4 are engine and architecture-related (essentially adding up to even better sounding, more detailed effects than v3), a couple of more ‘front-facing’ changes have been implemented, too. With so many presets in the library, the addition of a file browser is very welcome. Inspired by OS X’s Finder and contained in its own window, it’s a simple affair that makes light work of navigating effects categories and their contents. It even has a search function, although a column view is notable by its absence.
Also new for Nebula 4, individual presets can now be given their own skins. Disappointingly, only two of the bundled presets actually capitalise on this: the Violet and Yellow Royale compressors. Other than that, you’re looking at a very small set of handsome but rather tedious silver fascias, with nothing to differentiate one preset within an effect category from another. Still, it gives thirdparty contributors the ability to give presets their own identities, which can only be a good thing.
Grab Nebula
Nebula 4 really is all about the sound and specificity of its many compressor, EQ, reverb, filter, tape, preamp and modulation effect presets, and in that regard, there really is nothing else quite like it. Sonically, it’s never less than breathtaking, whether clamping character compression down on a drum bus, sweetening a vocal, bringing the best out in a guitar, phasing a synth pad, or powering a mastering chain. The interface works well enough, too, and with a Zero-Latency version of the plugin (for real-time recording/monitoring at the expense of a huge CPU hit) included alongside the regular highlatency one (for mixing), lag isn’t as much of an issue as it once was.
Ultimately, as long as you’re down with its particular workflow and functional paradigm, Nebula 4’s compendium of stunningly realistic and responsive effects emulations is a godsend for any producer or engineer.
“The compendium of stunningly realistic and responsive effects emulations is a godsend”