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Acustica Audio Diamond Color-EQ

Equaliser Plug-in By Sam Inglis
Published July 2017

Acustica Audio Diamond Color-EQ

The first plug-in from Acustica’s new Diamond range recreates the master bus EQ of a master!

Acustica Audio have pioneered the use of dynamic convolution to recreate hardware in software. In its early incarnations, this technology had the reputation of being complex and difficult to use, but the company’s ever-growing range of Acqua plug-ins shows that it is possible to present dynamic convolution in a user-friendly fashion. As a result, the Acqua range has won numerous fans in professional mixing circles. Among them is Italian engineer Luca Pretolesi of Studio DMI, one of the world’s leading specialists in mixing EDM and other electronic music; and the first product in Acustica’s new Diamond range is a plug-in that recreates Pretolesi’s own mix-bus EQ chain.

Back To Basics

Though it combines elements ‘sampled’ from several different source devices, Diamond Color-EQ distils these into a simple processor with very few controls. At either side of the plug-in window you’ll find input and output gain dials. These have more than mere utility value, because the plug-in includes a switchable preamp stage that needs to be driven appropriately, if used. The EQ itself features four bands, in an arrangement that is very unusual but which turns out to be surprisingly useful.

The two leftmost bands are labelled LF and LMF, with frequency ranges that span 20-60 Hz and 80-120 Hz respectively. A third band, labelled HMF, has a fixed centre frequency, while the final HF band can be set anywhere between 15 and 50 kHz(!). The EQ gain knobs are not calibrated, but the maximum boost available seems to vary, from about 10dB for the HF band to twice that for the LF.

There are no bandwidth controls at all, and you don’t have to play with Color-EQ for long to realise that the HMF and HF bands work across a very broad area of the frequency spectrum. As an experiment, I routed some pink noise through it and examined the results on a spectrum analyser; at maximum boost, the HMF band appears to apply a boost that is pretty much flat from 500Hz to 10kHz, while the effects of the HF band extend well into the audible spectrum even with the centre frequency set to 50kHz. A surgical EQ this is not!

In Use

The Acqua series represents a conscious effort by Acustica to package dynamic convolution in a format that won’t alienate people accustomed to ‘normal’ plug-ins. Each Acqua plug-in ‘samples’ a specific hardware device, and comes with a skeuomorphic graphical interface tailored to suit. Despite this, though, the Acqua plug-ins I’ve tried still fall slightly short of conventional plug-ins in usability terms, thanks to large installation files, an annoying authorisation system, slow loading times, unresponsive interfaces and heavy loads on the host computer. So it’s a pleasure to report that most of these issues have been swept aside in the first Diamond plug-in.

The Diamond Color-EQ installer is a mere 133MB in size, perhaps reflecting its relatively simple feature set, and is authorised using a brand-new and completely painless licence-manager utility. Better still, once installed, it looks and feels pretty much like any other plug-in. It is neither slow to load nor sluggish in its response to mouse input, and there’s no unwanted lag in the behaviour of the controls. And although dynamic convolution will never be the most CPU-efficient process, system load is unlikely to be an issue when you’re using Color-EQ in its intended role as a bus processor. The only tell-tale sign that this is a dynamic convolution plug-in and not a modelled one is that although the controls appear at first glance to be continuous, they are actually stepped, albeit in small enough intervals that this is not a problem.

So what does it actually sound like, I hear you ask. Well, I’m slightly reluctant to believe in the idea of an equaliser that’s tailored for specific musical genres, but if there is such a thing, then Color-EQ might well be it. I first tried it as a master bus EQ on some acoustic folk recordings, and although it can certainly make a positive contribution in that role, it didn’t seem like a natural fit. The HMF band is too broad to offer any control, and the preamp warmth and HF lift easily become gritty or plasticky. I had considerably more success on some rock mixes, where the preamp warmth and HMF boost can bring out a nice sparkle and presence in the upper mid-range, and the LMF band can subtly emphasise the ‘upper bass’ region that is often so important. However, I wouldn’t want it as my only master bus EQ, because the HMF band gives you no choice as to which parts of the mid-range get targeted.

As luck would have it, though, the next project I was asked to mix was a collection of instrumental electronica tracks with a strong ’80s influence, and here, Diamond was clearly in its element. Simply inserting it on the mix bus, activating the preamp stage and turning up the HMF and HF bands made a huge difference to the sound of the raw tracks, all of it positive. If you like your electronica to sound slick, glossy and punchy, these elements of Diamond Color-EQ seem to work hand in hand to do most of the heavy lifting with minimal user input. And at the low end, meanwhile, the very limited range of the LF and LMF bands is an asset in bass-heavy music, letting you focus them precisely on the elements that are foundational to any given mix. As with so many classic pieces of gear, the genius of Color-EQ lies in its simplicity. When it’s not the right thing for your track, you’ll know straight away; and when it is the right thing, it’s the work of seconds to dial in the results you need.

Required Viewing

If you’d like to learn more about how Luca Pretolesi himself uses the Acustica/Studio DMI Diamond Color-EQ plug-in, we are sharing an exclusive video from the Studio DMI team demonstrating some of Luca’s tips and tricks. For more videos, head to the SOS YouTube channel.


  • Can sound great.
  • Minimal feature set makes it extremely easy to get results on the right material.
  • Eliminates the usability niggles that slightly marred the Acqua plug-ins.


  • Minimal feature set means that on the wrong material, you won’t get results!


In Acustica’s hands, dynamic convolution becomes an ever-more compelling alternative to conventional modelling plug-ins, and never more so than in this new master EQ.


€149 including VAT.