Acustica Cobalt Bundle Mega-Review Acustica Cobalt Bundle Mega-Review
Cobalt is an extraordinary bundle of mastering grade plugins from Acustica Audio. Michael Frasinelli breaks it all the way down. Acustica Cobalt Bundle Mega-Review 4.5

The Blue Brothers

When I first started honing my mastering chops to the point of offering mastering commercially, my mentor, Randy Kohrs, supported it on one condition; I needed the right tools for the job. Like everything else, if I was going to do this, I was going to do it right. High-end mastering compressors, EQs, conversion, and an extremely well treated room. I’d also need to pick the choice mastering software and plugins to help fill in what my hardware arsenal currently lacks, from Izotope to Plugin Alliance but man, why did no one tell me about Acustica Audio

earlier? As a full blown gear and hardware geek (a family member actually once called me, legitimately concerned over my ever-growing hardware slash microphone habit), Acustica has one of the most diverse emulation catalogs I have yet seen in the digital world. From vintage classics, to modern powerhouses, to high end boutique gear, to obscure but useful pieces of yesteryear. It wasn’t until I recently received a healthy portion of Acustica Audio’s product line for review though, that I realized how serious the Italian company is about modeling.

“…man, why did no one tell me about Acustica Audio earlier?”

Paying the HDD Piper

“…this fast became one of those pieces where the plugin being reviewed gained permanent residence on just about everything it was tested on”

To begin, I spent an entire day just downloading plugins (the files are pretty large – up to a couple of GB) and then I began testing them. To experience pure audio- induced bliss from a bunch of plugins is somewhat unusual but herein lies the real story about Acustica Audio. They have cunningly replicated some of my all time favorite hardware, including classic pieces that I have yet to see emulated anywhere else. They accomplish this by using a form of nonlinear, artifact-free “hardware sampling” called V.V.K.T. or Vectorial Volterra Kernels Technology as opposed to algorithms to get the most authentic sound possible – with the tradeoff being a solid hit to your CPU. One of their most recent offerings, Cobalt, is what I was instructed to dive into first and this fast became one of those pieces where the plugin being reviewed gained permanent residence on just about everything it was tested on.

Specialized DNA

As a bundle or collection, Cobalt covers an incredible amount of ground. Drawing inspiration from a vast array of sources, there’s something for just about every application. Each of the four modules is based on a boutique hardware unit created by Luca Martegani, a man whose work Giancarlo (owner of Acustica Audio) respected so much that he decided to create these emulations as part of Acustica’s “Endorsed Line” of plugins. With Cobalt, you receive a mastering grade, passive, tube equalizer based on Luca’s LM 9736 unit, which is in turn loosely based on the Pultec EQP-1A. Next you get a complex, dynamic EQ, a very tasty preamp and finally a mastering grade tube compressor emulated after Luca’s LM 9804 unit, which is said to be based on “what many consider the best compressor ever created.”

“Cobalt covers an incredible amount of ground, and there is no short way to reveal it all in one article.”

…which leads me to believe it’s based on one of the classic, variable-mu style compressors. If you just want the coloration and none of the processing, the included preamp plugin allows you to choose from the preamp stage of Luca’s compressor or equalizer, with a further three, additional tube preamp options. As with a real preamp, you get input and output gain knobs for driving the plugin to produce your intended results, which is something also found throughout the rest of this suite. The included dynamic equalizer i stated by Acustica Audio to be a clever “remix” (read hybrid) of the LM 9736 and the LM 9804 processors for which, in addition to Luca Martegani, Giancarlo enlisted the help of Stefano Dall’Ora of SoundDrops. This handsome unit is literally bristling with controls but is especially intriguing, since every dynamic EQ plugin that pops to my mind is a clean, surgical, utility tool, built from the ground up in the digital domain and not intended to have a sound of its own, let alone emulate real life hardware. 

“The dynamic EQ is especially intriguing…”

LM 9736 Vacuum Tube EQ

Let’s begin with the EQ plugin (the LM 9736 Vacuum Tube Equalizer). Anyone who has used a Pultec style, passive program equalizer will be at home here. You have the classic option to cut and boost the same frequency at a handful of points (though in this case they are different to the original Pultecs) and this has a way of both enhancing and tightening the selected frequency point at the same time. I especially love to use this on kick drum and bass, traditionally the hot spot is around 60Hz and 100Hz on the Pultec units. 

The same behaviour can also be duplicated around 200Hz or 400Hz on vocals. There are a fair few more fixed frequency points on the Cobalt EQ than any original Pultec hardware – or any other plugin, at least that I’ve seen. My go to 60Hz boost and cut trick is catered for and, though there ‘s no 100Hz boost and cut, I found that boosting 100Hz and cutting 90Hz by equal amounts did the trick. I’m not going to sit here and compare the LM 9736 point by point to an original Pultec hardware unit, because this is not what it’s specifically emulating. It was built to be something greater, yet inspired by classic tube program EQs of the last century. In my opinion, it accomplishes this goal with ease.

“It was built to be something greater, yet inspired by classic tube program EQs of the last century. In my opinion, it accomplishes this goal with ease.”

“…The LM 9738 just has that incredibly forgiving, ‘hard to make it sound bad’ quality of the best maintained Pultecs in the world.”

APN | Michael Frasinelli Mix Bus (Colbalt EQ, Preamp On) (-2dB 90Hz) (+2dB 100Hz) (+3dB 15KHz)
APN | Michael Frasinelli Mix Bus (Colbalt EQ, Preamp Off) (-2dB 90Hz) (+2dB 100Hz) (+3dB 15KHz)
APN | Michael Frasinelli Mix Bus (Cobalt Bypassed)

I put the LM on the mix bus of a new RnB project that I recently started working on, turned on the preamp, boosted 100 by 2dB, cut 90 by 2dB, and then boosted 15Khz by 4dB. I could immediately hear the life get sucked from the song when bypassing the plugin. As a matter of fact, after trying the very same thing (boosting between 1-4dB) on a number of tracks I am quite certain this EQ has the smoothest top end I’ve heard from a plugin. Even a subtle boost of 1 or 1.5dB makes a world of difference in many instances. Based on my experience so far, this is certainly an EQ to use for ‘sweetening’. Maybe I’m old fashioned (at the ripe old age of 22), but I would’ve loved some more duplicated frequency points for the boost/cut trick but again, this isn’t a 1:1 Pultec emulation and it isn’t meant to be. The LM 9738 just has that incredibly forgiving, ‘hard to make it sound bad’ quality of the best maintained Pultecs in the world.

This plugin is simply a beast to use on vocals, as well as for the general sculpting and enhancing of individual tracks. With a well recorded vocal where some tone shaping and shelving of the low end is all that’s needed you can use the separate low shelf boost and cut bands more traditionally allowing you to have some fun if you wish to create peaks by engaging and tweaking both at once.

APN | Michael Frasinelli Lead Vocals (Cobalt EQ, Preamp On) (-1dB 75Hz, +1.5dB 200Hz, +2dB 1.6KHz, +3dB 20KHz)
APN | Michael Frasinelli Lead Vocals (Bypassed)

Another “upgrade” that many vintage tube EQs don’t have (in addition to the separate low cut and boost bands, plus the separate high boost and cut bands with variable Q), is the very handy presence band. This comes in the form of a boost only band that uses a bell curve – so there’s no need to waste the high boost option when you can simply dial in between 680Hz and 7.5KHz with the presence band (I tended to like 1.6KHz or 2.2KHz boosted to taste on vocals). This leaves the actual high boost to do what it does best. Add “air”, “shimmer”, and “sparkle”.


The LM 9736, and all of the other plugins in this bundle, feature stepped parameters due to the nature of Acustica’s “hardware sampling” process – as if plugin recall wasn’t easy enough! Plus, with stepped frequency selections, it prevents the all-too-familiar situation of spending too much time fretting over fine-tuning center frequencies to the exact micro-Hertz, as is the case with a lot of fully sweepable equalizers. That being said, if your vocal or mix bus/master requires surgical EQ, a 2nd EQ in series with Cobalt is probably your best bet, which is expected for this type of design. Be aware though, that you do get significantly more options with this unit versus its vintage counterparts, including additional frequency points, an additional band, an input and output gain, as well as the option to bypass the virtual preamp stage to reduce the ultra musical coloration if you so wish.

LM 9804 Compressor

The LM 9804 compressor plugin is surprisingly modern sounding for a tube style compressor and, for mastering purposes, that is greatly appreciated. This is not to say it doesn’t impart beautiful saturation to your source, because it does! It is not as inherently “soft” (color and transient) sounding as a Vari-Mu or even my modded Tube Tech LCA-2A while mastering or on a bus. It’s the kind of compressor that brings everything up in the mix and surprisingly it’s incredibly punchy sounding – even at modest gain reduction settings. I found that because of this, it can sound somewhat similar to many solid-state compressors with these coloration characteristics, which is far from what I was expecting. Don’t get me wrong, you still get very open and realistic tube warmth and fullness – just without a veil of blatantly vintage character. 

That being said, the compression itself is still very much on the laconic side – staying authentic to the type of compression it’s emulating, as well as the particular LM unit being modeled, I suspect. It has a fixed ratio and therefore relies on other parameters, especially input gain, for achieving an ideal gain reduction. I’ve had a slew of projects recently that all fall under very modern genres for the most part. House, Country Rock and a client who makes both “new age” RnB, as well as some electronically influenced Jazz have been the most recent. As I touched on above, a lot of the famous tube compressors I will reserve for more natural sounding genres/less dense mixes such as singer-songwriter and acoustic tracks but I’ve been able to use the Cobalt compressor on much denser, busier mixes with excellent results.

The LM 9804 lacks a HPF in the sidechain which is a shame, as I often like to let the low end breathe on buses, but it still performs with alacrity on these applications, as long as I am not too heavy handed when there are concerns about the low end being over-compressed. I feel like this could have also been solved with a mid/side feature, but I am guessing that the original unit that Acustica emulated did not have such capabilities, so to stay authentic to the hardware, these features were

omitted. The workaround I did find for this issue however, is the SHMOD feature that’s included in Acustica’s recent compressor plugins – as well as the dry/wet mix knob. The SHMOD parameter affects the attack curve of the compressor, changing the characteristics and behavior of the processing. When it became apparent that the low end was losing some oomph, I found that increasing the SHMOD knob enhanced and redefined the transients.

APN | Michael Frasinelli Background Vocals (Cobalt Comp, Preamp On) (4dB GR) (Insane Mode)
APN | Michael Frasinelli Background Vocals (Bypassed)

Option two involves turning down the wet/dry knob to let more of the dry signal through, though of course the blended dry signal isn’t limited to just the low end. Even with these features, this compressor likely wouldn’t be my first choice to use on most drum buses, but it is especially beautiful on the mix and background vocal buses. Simply turning the compressor on (with the preamp stage engaged) adds an impressive amount of life and dimension to the track when you park it on the mix bus. Add 1-3dB of compression with your ideal settings, back the mix knob down to about 75% wet and wow. It’s just shocking how good it sounds. It doesn’t remind me of any particular piece of tube gear per se, rather bits and pieces from a handful of different models. For example, when I set the compressor the way I want it (in this particular case, achieving about 2dB of reduction on the mix bus of a slower RnB song), the vocals pop forward in the mix – there’s a veil of dimensional purity that gets added to everything, which in turn makes each element of the song jump (proportionately) out of the speakers, whilst subtly warming the entire mix.

“there is a veil of dimension that gets added to everything which seemingly makes each element of the song (proportionately) jump out of the speakers, whilst subtly warming the entire mix.”

APN | Michael Frasinelli Mix Bus (Colbalt Comp, Preamp On) (2db GR)
APN | Michael Frasinelli Mix Bus (Colbalt Comp, Preamp Off) (2db GR)
APN | Michael Frasinelli Mix Bus (Colbalt Comp, Preamp On) (Insane Mode) (2db GR)
APN | Michael FrasinelliAPN | Michael Frasinelli Mix Bus (Cobalt Bypassed)

With low gain reduction settings and SHMOD at the default ‘2’ setting, the kick drum and snare seemed to gain extra punch, whilst being ever so slightly glued (level wise) into the mix.

The particular warmth or saturation applied also seemed to give each part of the mix its own space, adding to the sense of energy the unit bestows overall. This appeared to be the case with most of the projects I tested the LM 9804 on and I found myself always setting the release on the faster side with the attack somewhere in the middle, speeding up the attack slightly if the tempo increased. A benefit of such a relatively slow attack is that no matter the setting, it always lets the transients through. My personal settings normally ending up being around 25-40mS.


“…even saving myself the precious CPU by leaving Insane Mode off, I was still extremely impressed by the LM 9804 – more so than I can remember being with a plugin.”

If you want to squeeze out that last little bit of authenticity, there is a button labeled “Insane Mode” which is engaged by default when you open a new instance. My first thought was “Okay, this must be the ultra coloration, obliteration mode”, but I couldn’t have been farther off! Insane Mode kicks the “hardware sampling” of the unit into overdrive, giving you an even more realistic, responsive, and authentic sounding plugin – with the trade-off being an additional hit to your CPU, which makes sense. I personally found that even when saving myself the precious CPU cycles by leaving Insane Mode off, I was still extremely impressed by the LM 9804 – more so than I can remember being with a plugin, especially an emulation of tube gear which seems to be the toughest to get right. With Insane Mode engaged, which I would probably reserve mainly for mix bus and mastering applications, you do squeeze out some final percentage points of authenticity, responsiveness and accuracy – though I wouldn’t call it night and day. This plugin sounds so good though, that the difference is not significant enough to obsess over.

Cobalt DynEQ

Upon instantiating the DynamicEQ, I have to say that it looks different from any dynamic EQ I’ve seen before. I’m not going to lie, the first time I opened it, I had no idea how to set it for the first half an hour of testing, so I turned to the trusty (and in-depth) manuals that Acustica supplies online for each of their Acqua plugins. After reading though it became clear this plugin goes about dynamic equalization in a very interesting, unique, but nonetheless useful way. Let me try to simplify this so we can get to how it sounds (spoiler alert, it sounds great). So the EQ1 section controls the actual dynamic equalization that will take place when the signal is above the Dynamics / Compressor’s threshold and exceeds your Range value. EQ2 affects the sidechain of the Comp 3 / Dynamics section (think compressors that have built in high pass filters in the sidechain – it’s the 

same idea) that determines when and how easily the equaliser from the EQ1 section kicks in. A good way to begin is to set EQ1 so that you are happy with the sound, then set up the Comp 3 / Dynamics section, adjusting EQ2 till you are happy with how the sidechain of the Comp 3 / Dynamics section is reacting and then hit the Dynamic EQ button. Actuating the Dynamic EQ button will return you to the sound of the flat EQ with the DynamicEQ (EQ1 settings) kicking in when the signal is above the threshold and the gain reduction then exceeds the Range parameter. Basically, the Range setting is a limit to the amount of gain reduction that can be applied before the dynamic EQ kicks in. I found that I typically set my Range knob rather low in order to make it easier for the dynamic EQ to begin, unless there was a very large dynamic range between one part of the song and another.

Just utilizing the compression features you can boost a sibilant range with EQ2 (let’s say, 4.3KHz), set your Q and that area will get compressed more than the rest. Or, in the EQ2 section, you can cut the high end (I found 11.5KHz to be a great place for this) and this will ensure there’s less compression occurring at 11.5KHz and above, with less and less occurring the more you cut with the band in EQ2. When that dynamic equalization does occur, it’ll be acting in the way you tell it to in the EQ1 section. Now, let’s say there’s a louder section of the song (like a chorus) in which you want some additional air or top end, but you don’t want it throughout the entire song. Let’s start by dialing in +2dB (or whatever you want) in the High Boost section of EQ1 at 11.5KHz. Set up your EQ2 sidechain and threshold so that the gain reduction only exceeds the range during the choruses. Now the 11.5KHz boost will only activate during the louder choruses. Pretty cool, right? Instant air added to your mix, but only during the parts where you want it, making the mix more alive and exciting! These applications are literally just scratching the surface. So what about the dynamics section, taken from the LM 9804 compressor plugin?

APN | Michael Frasinelli Mix Bus (Colbalt EQ, Preamp On) (-2dB 90Hz) (+2dB 100Hz) (+3dB 15KHz)
APN | Michael Frasinelli Mix Bus (Colbalt EQ, Preamp Off) (-2dB 90Hz) (+2dB 100Hz) (+3dB 15KHz)
APN | Michael Frasinelli Mix Bus (Cobalt Bypassed)

Unlike the LM 9804, you get much faster attack settings on the DynamicEQ, with the fastest being .5mS. With the dedicated LM 9804 compressor plugin the fastest option is 20mS. You also get a valuable ‘cut’ option for the presence band in the EQ1 section on DynamicEQ and 3 ratios (Mantis, Violet, and Cobalt), each based on three separate emulations from both Acustica and SoundDrops.

  1. Mantis, which is based on a sampling of Stefano of SoundDrops’s PWM compressor (pulse width modulation… think PYE, Dave Hill Titan, Great River PWM-501, Crane Song STC-8, and even the Distressor), which is said to have a “very moderate” ratio.

  2. Violet, based on the “Violet” sampled compressor included in Acustica’s Nebula 4, with a “medium compression ratio”.
  3. Cobalt, which is the same as the LM 9804 plugin, which seems to have quite a high ratio with a level of program dependence to it.

The inclusion of low, medium and high ratios make the DynamicEQ far more versatile than it would have been if it were stuck with only the original LM 9804 ratio. I would’ve loved the option to separately trigger each band of EQ1 separately instead of all at once when the broadband gain reduction crosses the range, with each band controlled by separate dynamics sections – but I’m not going to hold that against this unit or Acustica Audio. With the wide range of dynamic EQ plugins out there nowadays, this iteration is truly unique. It achieves a more analog, almost automation-like approach to this form of processing which can be equally useful. I can only imagine the nightmare of “sampling” the available options there’d be if each EQ1 band had its own dynamics section, threshold, and range.

“With the wide range of dynamic EQ plugins out there nowadays, this iteration is truly unique.”


The handy, blueprint style matrix in the bottom right corner of the plugin gives you a basic, visual representation of what is going on, routing wise, between the different sections – though I found the external sidechain connectivity to be difficult to implement in Logic Pro X, as Logic has its own standalone, sidechain functionality that doesn’t seem to work with Acustica Audio plugins. Cubase Pro 9 on the other hand worked perfectly, showcasing the versatility of the Cobalt DynamicEQ even further. I set up an external sidechain so that with every beat of the kick drum, just the low end of the bass guitar was cut, leaving the growl of the bass guitar to sit over the kick, only to have the low end of the bass come back up in between those kicks. These are only guidelines of course; you can really go down the rabbit hole with DynamicEQ. Is there room for another dynamic EQ in your arsenal? I’d say yes, a more traditional one that embraces being digital by being ultra transparent, multiband with separate thresholds per band (like I’m used to) and infinitely tweakable. But, as far as a dynamic EQ that imparts some color and makes broad EQ strokes instead of minute, surgical ones, this could likely be the only one you need.

“…as far as a dynamic EQ that imparts some color and makes broad EQ strokes instead of extremely surgical ones, this could likely be the only one you need.”

Cobalt LXM96 Preamp

I did have trouble turning on the preamp section of each processor plugin due to a hefty spike in CPU usage. This (and overloads in general),  happened most often when I tried to run multiple instances of Cobalt plugins in series, though due to the nature of DAW multithreading, this is not limited to strictly Acustica plugins. I have the most recent 2.7GHZ, 12 Core, 64GB of RAM Mac Pro, but to be fair, there was already a hefty complement of plugins populating the mix. Whilst Acustica gear sounds heavenly, it is pretty CPU heavy across the board. If you wish to track with these units, you’ll find a “ZL” or zero latency version of each plugin that comes with Cobalt, but again, at the cost of additional processing power. I did find that if I bypassed the preamp stage of each Cobalt unit (which still leaves coloration by the way, just not quite as much since the preamp stages’ coloration is bypassed) and then opened up an instance of the standalone Cobalt Preamp plugin, I was able to squeeze an extra instance of a Cobalt processor on as well. Plus, with the preamp you get to really pick and choose what kind of saturation you want from the five options and then drive the preamp anyway you want without directly altering the processing, as would be the case on the Cobalt DynamicEQ or LM Compressor.

Anyways, the CPU load kind of makes me work with the same mindset I do when using my hardware, where I have to carefully pick and choose the important places to use each unit, as I do not get infinite channels of outboard, obviously. Same kind of thing here, which can be a bummer, but the hardware mindset really makes you think through each move and prevents you from over-processing which is almost a silver lining in a strange way. There are obvious sonic benefits in having such great sounding options. CPU overload was mainly an issue in Logic Pro X, making it possible to access only about 25% of my CPU, greatly limiting my situation.

In Cubase Pro 9 however, I was able to use over twice the instances of Cobalt and fully utilize the multithreading capabilities Acustica Audio has been working on so diligently with each core upgrade (in Core 9 and 10 the plugins split CPU load more equally over multiple processor cores). I found that all three of the main Cobalt processors work beautifully when in series and on the same channel. All but ensuring that every time I have the compressor on a source, especially the mix bus, the equalizer will follow – if not the equalizer and the DynamicEQ. Granted, it takes a lot of math to make plugins sound this good, so I can easily forgive the CPU load, especially whilst working in 96K. Also, a quick note on the compressor and DynamicEQ offerings of Cobalt if you are using these traditionally on stereo applications. Be sure to turn the ‘Stereo Link’ knob to full, and on both the equalizer and compressor, engage the ‘Control Link’ button. In addition to that, both the EQ and DynamicEQ open up with all bands bypassed, so make sure you hit the ‘In’ or ‘bypass’ button above each band or pair of bands so it illuminates.

“It takes a lot of math to make plugins sound this good.”

With all courses now covered, it’s time for the dessert tray. the Cobalt ‘Pre’ plugin. As I said, it offers five preamp emulations from the other Cobalt plugins as well as three different preamps! When setting up my gain staging the way I would with any other hardware line or microphone preamp, I found that whilst the output trim knob did affect the actual gain of the unit and therefore the level of my mix, the input gain knob did not, simply applying additional drive to the preamp unit without actually affecting the levels. For instance, when I turn certain preamp emulations’ input gain up to 10, there’s certainly not a 10dB gain increase, though there was some additional perceived loudness from the saturation. Basically, the input gain knob acts as a dedicated drive feature. There are great pictures of spectrum analyzers in the manual showing the harmonic distortion added from each preamp selection for reference, using a 1KHz sine wave as the source, but the following is my personal experience with each preamp mode on the mix bus, and therefore, a more complex source. Based on that, the options are as follows:

APN | Michael Frasinelli Mix Bus (Colbalt Pre) (Mic ST) (+4 Drive)
APN | Michael Frasinelli Mix Bus (Colbalt Pre) (Mic 2) (+4 Drive)
APN | Michael Frasinelli Mix Bus (Colbalt Pre) (Mic 1) (+4 Drive)
APN | Michael Frasinelli Mix Bus (Colbalt Pre) (EQ) (+4 Drive)
APN | Michael Frasinelli Mix Bus (Colbalt Pre) (Comp) (+4 Drive)
APN | Michael Frasinelli Mix Bus (Cobalt Bypassed)

1.     The unit opens up initialized with Mic ST selected (which is a combination of both the Mic 1 and Mic 2 emulations). When I threw this preamp on the mix bus to accentuate the character, it seemed to add a nice amount of width to the track almost as if some form of mid/side processing had been applied and the transients of the kick, snare, and hi hats seemed to get enhanced as well, adding a bit more punch to the track. Even certain transients within the vocals seemed to come forward more in the mix every now and then, with a subtle broadband saturation across the rest of the track. The more I drove the input stage, the more the transients seemed to shift forward with the saturation increase, especially in the low end and high mids. So it seems as if these two parts of the spectrum get affected the most by this drive, with notable changes in the kick, bass, snare, and high hats – more so than anywhere else.  The lows also fattened up as I continued to drive and, at extreme settings, the kick drum seemed especially affected, though I would not use such drastic settings on the mix bus as it can get a bit wooly, muddy, and overbearing when the kick becomes more and more bass heavy whilst its attack gets more pronounced and extreme. This would be an excellent feature on the parallel kick track, though! Overall I found this setting most usable in moderate amounts directly on a track instead of a bus or aux send.

2.     Mic 1 was similar to the above unit, except it seemed to affect the mids much more than any other frequency range – the the most audible impact being on the vocals and snare. Also, air was added to the vocals, barely affecting the rest of the high frequencies. The more I drove Mic 1, the more this mid range punch and enhancement increased. With higher levels of drive, the sense of air became more and more palpable on the overall track, though at a high enough frequency that it did not significantly affect the fundamentals or transients of any of the instruments higher up in the spectrum, such as the high hats. This would be great to exercise directly on the mix bus of certain projects (likely with moderate settings), on a vocal or snare track, or driven hard on the snare or vocal parallel track.

3.     Mic 2’s saturation and coloration seemed to be centered lower than Mic 1, but also higher than the low-end saturation of Mic ST. It really brought out the attack and punch of the kick drum more so than Mic ST, but without fattening up the very low kick and sub bass frequencies nearly as much (which may have contributed to the punch of the kick being more prevalent than with Mic ST). A big benefit of this is that when driven, it increases the punch of the kick drum, without over-enhancing the very bottom frequencies that could make the low end overly muddy or wooly like Mic ST seems to be capable of if you drive it too hard. This same saturation also brings out the high mids, just above where the snare typically lives, outlining the upper frequencies of vocals (around 7KHz or 8KHz), therefore manifesting a sense of air at a slightly lower frequency than Mic 1. The harder I drove Mic 2, the more all the elements of the mix were brought forward, though this increase in perceived loudness was proportionate besides the two focal points I addressed above. If you want a tight kick drum without too much low end, or more present vocals or electric guitars without diving into the presence range (4KHz-6KHz) that can often be perceived as harshness, Mic 2 will likely fit the bill. I can definitely hear how the character of Mic 1 combined with this option yields the results of Mic ST.

4.      The option labeled EQ (based on the preamp stage of the LM 9736 EQ from above) on the other hand, seems to focus it’s character on the mids and up – similar in effect to a high shelf, though of course this is done with harmonic distortion and not EQ. This brought out the vocals, snare and hi hats, whilst leaving the attack of the kick seemingly unchanged. I’m sure this would also affect an electric guitar track as well. The more it was driven the more obvious these qualities became. A very subtle, low mid warmth seemed to remain consistently throughout these different settings. I found this to be a great way to brighten and liven up a track without messing up the balance of the overall mix. The subtle increase in the amount of low mids balanced out the mid-high enhancement, helping to prevent any possible shrillness.

5.     The COMP preamp is from the LM 9804 compressor that Cobalt provides. I found this to be the the most balanced sounding and therefore the most versatile setting of the Cobalt Pre plugin. No wonder I loved the Cobalt compressor so much on buses, including the mix bus! Subtlety warmth, openness, and dimension permeate the entire track, without any one particular range getting targeted significantly more than the others. This is a great way to sweeten just about anything. The more I pushed this emulation, the more proportionate perceived loudness I got across the entire song (which could be very handy when mastering certain songs, though one should be careful about how much harmonic distortion they are introducing). At extreme settings, you get the oh-so familiar sound of slightly overdriven tubes that I can see working well on drum or electric guitar buses.


Overall, I have been extremely impressed by Cobalt. It is rather spooky how much ‘Ones and Zeros’ can sound like our beloved hardware nowadays and this is one of the best examples of the trend I’ve ever heard. Yes, it takes a lot of’ Ones and Zeros’ for a perfect system (like a computer) to emulate something that is imperfect and nonlinear by nature (like studio hardware), but once you hear this plugin suite, I think you will instantly forgive the slight inconveniences and make these beautiful emulations a part of your mixing or mastering process.

“It is spooky how much ‘Ones and Zeros’ can sound like our beloved hardware nowadays and this is one of the best examples of the trend I’ve ever heard.”

Price and Availability

Acustica Audio’s Cobalt weighs in at $201.00 ($160.09 Pre-Order sale), 179.00 Euro (143.20 Euro Pre-Order sale) and you can purchase directly here.


Compatible on Mac:

VST 32bit & 64bit, AU 32bit & 64bit,

AAX 32bit & 64bit compatible host

Compatible on Windows:

VST 32bit & 64bit,

AAX 32bit & 64bit compatible host


Download the in depth Cobalt manual here

Many companies would charge the asking price for just one of the three plugins included. Normally, this much bang for the buck comes at the cost of cutting corners, but in typical Acustica Audio fashion, that is certainly not the case here.
  • Some of the most convincing emulations I have heard to date
  • Valuable assets for both mixing AND mastering
  • Choose the amount of color by engaging the preamp
  • Increased frequency points VS similar passive EQ plugins
  • 3 additional preamp options in addition to Comp and EQ
  • Four world class plugins for the price of one
  • CPU Heavy
  • Large downloads required for installation
  • No sidechain high pass filter options built into compressor
  • No mid/side functionality
  • No Mix knob on the Cobalt Pre
  • Extra ratios and faster attack of dynamic EQ not available on Comp

4 of 5

4 of 5

4 of 5

5 of 5

5 of 5

5 of 5

Michael Frasinelli

Studio Owner, Audio Engineer, and Producer based in Nashville, TN, mentored by and working closely with Grammy Award winning Producer, Engineer, and Musician Randy Kohrs. Highly active analog gear habit, with a plugin hobby on the side. DIY audio enthusiast with an interest in all things circuitry.


Top Shelf Music Group
Slack Key Studios

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