There have been several times in recent years when the release of certain software plug-In's have generated wild claims of no longer needing to own and maintain analogue audio outboard gear or continue to work OTB (outside of the box) many times this has been part of the marketing hype to try and peak interest in a highly saturated marketplace.
I'm sure I don't need to name brand names who have become rather well know for both marketing hype and or generating widely held opinion of the top spot's when it comes to the sound quality and realism of an emulated or modelled piece of vintage analogue outboard hardware so I'll leave that to your own thoughts and opinions.
However over the last 10 years or so one particular brand has quietly, but tirelessly been working away in the shadows, pioneered its own proprietary technology and been yielding rather outstanding sonic results while still remaining largely a secret or at least semi-unheard of to the wider audio engineering community. I myself have been following and using their products on and off for several years now, I've watched and experienced them slowly mature into what I now truly believe is about to explode into a domineering force in the audio Plug-in world - The brands name is Acustica Audio.
It Started With Nebula
In their own words taken from the Acustica Audio websites "History" Page:
Since the birth of Nebula in the summer of 2005, a dynamic collaboration was born between forward thinking developers, beta testers, audio engineers and equipment samplers from around the world. The research and development has gone through many stages and possesses innovative processes and technologies as of yet unheard of in other products or devices.The company's goal is to provide the most authentic reproduction of sampled vintage gear and other high end hardware devices, using the revolutionary technology "V.V.K.T." (Vectorial Volterra Kernels Technology) without the negative artifacts created by current convolution technology.After years of continous work, this creative forward thinking group has developed to a team of experts in knowing what it takes to serve the best "of both worlds" (digital & analog).


An Eye Opener !
Back when I first discovered Acustica and Nebula for myself I was mainly a Cubase user on Windows XP, which was perhaps "just as well" considering Nebula was both a VST and Windows only Plug-In. At the time the industry (and at least the circles I was immersed in building Pro Audio PC's) was deep into the grip of the software sampler revolution with Nemesys (later Tascam) Gigastudio and Native Instruments Kontakt leading the way. Stanalone server machines were being built in huge numbers to fulfill the demands by composers wishing to run full orchestras of huge sample libraries never before possible. We thought at the time PC power was really coming of age and yet the resource demands of these libraries was so high that we found ourselves producing such dedicated computers just to handle the hosting and streaming of these instruments leaving the master sequencing computers enough breathing space for the recording and playback of the MIDI data compositions.
So at this time everything was about sample libraries and virtual instruments......and sample driven virtual instruments 🙂 We were also in the midst of a "Reverb Revolution", Convolution Reverbs based on impulse responses had hit the market and were a very popular way to capture a real room space or a preset from a hardware algorithmic effects unit and then import it into a specially designed host plug-in encompassing some clever filtering and manipulation it was possible to use it almost exactly as the original source captured, it was quite remarkable at the time but very CPU hungry, especially at lower latencies. There were plenty of brands producing algorithmic audio effects plugins but we were not quite so overwhelmed with the current trend in new software recreations of must have classic hardware in same way we are today, for me it has pretty much reached a point where I can barely handle it anymore and am losing interest in yet another Neve, SSL, Pultec or Fairchild derivative each sounding questionably slightly better than the last but i supposed that's just progress.
Anyway .....Nebula! On first observation it appeared to be a sampler or sorts, at least in the fact that the audio wizards at Acustica had come up with a way of sampling real hardware Pre-Amps, EQ's, Compressors, Tape machines, Reverbs delays and other modulation effects in a totally intriguing way, one plug-in with multiple uses, One plug-in to rule them all ?
Nebula came with a factory library which in itself was rather impressive and a great example of what was possible, early 3rd party collaborators began to produce some rather impressive add-on libraries throught the use of Acustica's N.A.T. Sampler and best of all they sounded phenomenal ! Reverbs sounded ultra real and dynamic - in fact everything did, tape machines, entire consoles (long before any other Virtual Console plug-in had come along) there was some serious potential here but there were a couple of snags which I'll explain below.
How do they do it?
In the most simplistic way I can articulate Acustica use their own in house developed sampling tool N.A.T. sampler to capture the subject hardware just like a convolution impulse response creation, except its done many, many times with varying signal and transient levels passing through which allows the capture of "dynamic layers" (think of it like multi velocity drum samples) as well as the possibility of more complex parameter adjustments that were not quite so possible with the static and non-dynamic impulse response methods. This results in a huge collection of various files which are then arranged together in a library that the Plug-in can call upon, when you move a knob on the GUI the sample is switched to the appropriate capture and the signal is passed though that sample but this switching is also dependent on the level of the incoming signal thus making is dynamic. well at least that's how I understand it to work but will gladly be corrected by anyone else with a deeper understanding and articulation for a better explanation.
There is far more complexity to this but hopefully that gives you some basic idea of what is going on, It also explains why some of the plug-ins and libraries are rather large due to the size of the sampled library number or dynamic layers and parameter variations.
One very important factor to be aware of in order to get the very best from the Acustica products is the understanding and implementation of correct gain staging, failure to pay special attention to this will result in experiencing undesirable or unintended results.
LearnDigitalAudioTV created a video training series for Nebula that is well worth watching and this free excerpt explains the background to the required gain staging, I suggest you take the full course if you want to know as much as possible and of course read all of the relevant product manuals and documentation.
https://youtu.be/EaHQJ0T9iHg?utm_source=BlogPost&utm_medium=link&utm_campaign=Acustica&utm_term=Acustica%2BNebula%2BAcqua%2BLearnDigitalAudio&utm_content=LearnDigitalAudio
Horsepower
As I mentioned above there were some drawbacks to this whole Nebula experience in the early days which was also a shortfall for many other plug-in brands. As software developers began to realise the possibilities open to them with the rapidly increasing processing power unleashed by Intel processors and no sooner had the users thought processing power had come of age suddenly being able to run a stock EQ and Compressor on every channel of our DAW plus a few carefully selected mix effects as "fairy dust" We saw those resources begin to get gobbled up again by more complex plug-in designs sapping more and more CPU cycles than we had previously been used to. Running Nebula in multiple instances seemed to throw all those ideas of processing power liberation to the wall ! This was one CPU hungry little firecracker and it was pretty tough to run as many instances as we might have wanted or become accustomed to from some of the older plug-ins. We were "going to need a bigger boat" ! Dual CPU Multi-threaded Xeon powered RAM packed monsters were our thing back then but they were very expensive and so limited to who could afford them!
Latency
As with most high CPU demanding software applications in the audio world one of the major adverse effects of CPU load is the decreased ability to operate at low latencies, this becomes a problem when wanting to record and monitor though plug-ins or achieve playback of a heavy session to mix without audio artifacts such as pops and clicks or worse still total audio engine dropouts. This wasn't quite turning out to be the utopia we had hoped for and the DSP powered alternative of the time such as Digidesign/Avid Pro Tools HD TDM, TC Electronic Powercore and Universal Audio UAD were also winning a lot of favor by releasing CPU cycles and hosting their plug-in on their own dedicated DSP chips but sill with the latter two examples latency continued to be something of an issue.
Stability
"Hand in hand" with the two other issues mentioned above this one sealed the deal for many people, For some when the performance of a system was being "stretched to the max" a crash at just the wrong time is incredibly frustrating and after a while becomes too much disappointment to continue to endure. The benefits in other worldly sound quality did not outweigh the risk of random crashing or audio artefacts to which early versions of Nebula seemed to be plagued with in my own experience. In some instances it was difficult to run just one Nebula insert and eventually I gave up trying to incorporate it into my work on a regular basis, but I knew the potential was there and sooner or later things would improve, and they did. I continued to upgrade to newer versions as they were released, Nebula Server was a new exciting addition which meant you could run a standalone network linked server PC to power Nebula instances in your DAW but I never really got that into my studio templates and didn't want to have to invest and maintain a dedicated second PC for the task at the time. It was the same story when years later I got Vienna Ensemble Pro, the idea was nice but I never really got into the whole workflow.
As my interest in Nebula dwindled a little I was also more and more running Pro Tools as my main DAW of choice and trying to run Nebula through a VST wrapper in Pro Tools was an absolute "crashy unstable nightmare" so I shelved the idea and waited it out still thinking one day things might get better.
Enter Acqua
I cant remember when I first noticed Acquavox, maybe it was an Acustica marketing email or a KVR forum thread but it really looked good and was a new twist for Acustica, a single plug-in based on the Nebula engine with dedicated functionality, It made perfect sense to do for a few reasons, firstly the GUI and number of parameters for Nebula (although had improved greatly thanks to some awesome 3rd party skins - yeah it was skin-able, cool huh !) was a little complicated if all you wanted was a no nonsense two knob classic compressor, even if in reality it wasn't all that complicated it looked it, so came across as a little daunting.

Another thing made sense to me (even if it wasn't necessarily what Acustica were thinking) Why just release libraries for the same Plug-in over and over when you can easily release a new entire plug-in every time based on the same code you can keep reusing? You can package your library in a new GUI with dedicated controls, snazzy photo realistic graphics and call it a totally new product - makes perfect marketing and sales sense to me, plus with the added benefit that as new advancements are made in the core engine technology the newly released plug-ins can be built with that in mind making them better performing as time goes on.
The best thing of all about AcquaVox it was totally FREE !
The Acqua Powered Series Grows and Nebula Comes Of Age With Version 4
Acustica were on to something, they began to release new premium Acqua based plug-ins with beautiful GUI's and incredibly beautiful sounds based on sampled real hardware, the core engine quality had increased massively and continued to do so with every new release and the plug-ins really have begun to carve out a totally new high standard that many of the long established plug-in brands do not come close to reaching. I am by no means joking when I say these latest Acqua releases really do sound so close to hardware its not even a contest to bother arguing about anymore - I'm not the only one saying that either, for some light reading checkout the enormous dedicated thread on Gearslutz - a place where it would appear people live and die by their opinions.
It would also be untoward to not mention that Nebula has recently received an overhaul and update to Nebula 4 and new specially crafted libraries with integrated beautiful GUI's are being developed as we speak. Nebula 4 uses one such as an example included free called "Rose".
Nebula Version 4 With Its Included Free "Rose" Library

Efficiency, Stability And Latency Much Improved PLUS AAX and MacOS Support
With all the recent progressions of the Nebula 4 and Acqua technology Acustica have refined their engine many times resolving much of my previous concerns with stability and processor/memory efficiency with 64bit versions and added "Zero Latency" modules into the plugin bundles (at the cost of extra processing resources). They have also now added MacOS AU and AAX support so Mac and Pro Tools users can join the party, I have been able to pickup where I left off and once again enjoy these phenomenal products and be incredibly impressed with the latest releases, I'm now seriously considering how many of my other plug-ins and hardware outboard units I actually need to keep and I suspect you may feel the same way after spending some dome time with these plug-ins.
I strongly urge you do download a demo version of one or more of the plug-ins Acustica now offer but bear in mind these are still fairly CPU hungry beasts so you'll need a fairly current computer to get the most plug-in counts the system requirements table below taken from the Acustica Audio website tells all.

Join the Acustica Users forum and Facebook group where you'll find occasional sales discount codes offered, get involved in the discussion and join the revolution !
The Product List Grows And Continues To Impress
Gold is the latest plugin conceived, designed and created by Acustica Audio.
Five different equalizers, two extremely rare compressors, seven preamplifers and a routing control section prove how this is one of the most complex and complete ACQUA plugins ever released.
Anyone in search for faithful emulations simply must try this vintage British channel strip (complete with its standalone modules).
Acustica has decided to create an Anthology (Analog Dreamware Anthology) plug-in. It's not just a series of plug-ins: our goal is to provide all customers with a complete collection enclosing all inestimable outboard of the past.. in order to realize our goal we are ready to hunt them down to the ends of the earth.
"GOLD Standalone modules" consisting of:
- GOLD COMP
- GOLD PRE
- GOLD EQ
To help unleash the incredible potential of our GOLD’s modules, we have created a BUNDLE including each individual module of gold, enabling sound engineers to use each component separately, with a significant saving in terms of CPU. This will help enhance your mixes ensuring quality, versatility and the distinctive sound peculiar to Acustica’s plugins. We hope GOLD Standalone modules will meet our most demanding customers’ requirements.
Features actually supported in Core9:
- Variable speeds on vector nodes improving the sound quality of the compressors and allowing to reach very fast speeds and precision.
- Envelope followers based on control sources.
- Queue messages used for several widgets like knobs improving the behaviour, control, and stability of plug-ins.
- Hiddend components fault-tolerant inside nebula/acqua engine to minimized crash/bugs.
- New wrapper to get better balanced AAX format
- Several minor fixes and improvements (about trimming, sample rate conversion, distribution of sample rate packs, fixes on loaded program rate).
- This engine is linked to Nat4 to allows the full automatic compressor sampling.
- Switchmode optimization reducing CPU loading
- Lazy loading pattern introduced to improve the loading of the objects
LIME CRAZY88 is a bundle consisting of LIME BUS, LIME PRE, LIME EQ.
Lime provides our customers with different devices, sampled with Acustica’s technology and merged in a single plug-in. It’s inspired by a legendary inline mixing desk, and it’s aimed for those who are looking for a faithful emulation of that legendary sound. Without a doubt, Lime is one of the best choice to “mix in a box”. This groundbreaking channel strip delivers the quality and versatility to enhance any performance that requires that distinctive British sound. It features several preamps, two sets of low and hi pass flters, two four-band equalizers, 5 compressors (gate, ?) and an external dynamics side chain. You are free to change their routing order in the signal path as appropriate by selecting one of the 14 different configurations. Like we did for Sand and Coral, we decided to create standalone versions for each module. Lime strip includes 8 classic preamps to add warmth to your sound, while the standalone version includes 11 of them.
“Diamond - Color Eq” is the result of a collaboration between Acustica and Studio DMI
A new Italian project merging the passion and love for the art of Acustica and Luca Pretolesi’s homeland with the soul of Las Vegas.
Art and technique merge together culminating in a plug-in providing the most accurate digital representation of Studio DMI signature sound.
DIAMOND - Color Eq is the first plug-in of a new series called Diamond, designed to embellish and enhance your sound!
The Pre section adds extra harmonics to this Eq and can be switched off to use a chain of Eqs without summing the harmonics of each of them.
The thinking behind this process is to provide the full quality of the analog behavior, which means placing all the emphasis on quality over CPU resources.