Review: Slate Digital FG-X Virtual Mastering Processor, by Jason Finkel

Over the past 10-15 years the “Loudness Wars” have been waged against engineers and music fans alike.

The Slate Digital FG-X Virtual Mastering Compressor is a Mac/Windows plugin for VST, RTAS and AU, and priced at $249.

The desire to be the loudest and most ear-catching track has led to music that is robbed of dynamics and is fatiguing to listen to for long periods of time.  At the same time most artists don’t want their music to sound smaller than their genre peers.

Up until now the problem has been that you could not get too loud without the fatigue and transient loss.  However, after a couple of weeks of using the Slate Digital FG-X Virtual Mastering Processor, I’m not so sure that paradigm will exist much longer.

Quest for Control

I’m always looking to gain more control over my work.  Whether it’s improving my listening environment, upgrading my hardware, or getting new software, I’m down for whatever it takes so that I can get better results in less time and do more work.

Lately, I’ve been reevaluating how I go about mixing, particularly my non-use of a digital limiter across the buss.  I’ve refused to limit my mixes just so the client can hear them louder.  However, I find myself referencing mastered material and working my track so it’s competitive with that master.

The problem is that the journey of the track is not over at the end of the mix:  It’s probably going to need anywhere from 3-8 dB of RMS gain during mastering.  I wanted to close that gap between my mixes and mastered references by implementing a limiter to control the transients, lowering peak level, and increase RMS level.

I have always hated the sound of the more popular limiter plug-ins and was left to work each track individually in a mix with compression, peak limiting, saturation, or, more than likely, a subtle combination of all three. Even though the FG-X is primarily marketed as a mastering plugin, I was hopeful that mixing through the FG-X would give a lens to what the finished product could be and guide me in mixing accordingly to that end.

Over the last year-and-a-half I had been hearing about the Slate FG-X Mastering Plugin, but had mostly tuned it out because of my aforementioned aversion to limiter plugins on the bus.  But the FG-X is something different; it’s not your usual peak limiting plugin hell-bent on mushing up your sound and sucking out your low end, while giving just enough upper midrange distortion to annoy your listeners.  Here is what Slate is willing to say about how the plugin works:

“Two years ago Steven Slate and expert algorithm engineer Fabrice Gabriel started working out the concept for a digital audio process that could increase the level of a mix without altering the punch and dynamic feel, or make the mix sound squashed and lifeless. They started by researching saturation curves and their effect on various types of transient material. After several months of study and hundreds of listening tests, they made some fascinating discoveries. What they found, was that in order to transparently add level to a mix, a dynamic and intelligent transient saturation system would have to be developed.

New advanced algorithms were created to execute the extremely complex communication system that would be needed to properly perform the new dynamic operations. A new algorithm was formed, and the process was named ‘Intelligent Transient Preservation,’ or ITP.”

As I mentioned, I have been a fan of saturation as a way to lessen the need for peak limiting while increasing the RMS on an individual track by track basis, so I was intrigued how this would apply to the bus.

The Plug Itself

The FG-X has two parts: The FG Comp, a transparent mastering compressor, and The FG Level, a mastering limiter.

The FG Comp has the typical control set: attack, release, ratio, and threshold knobs.  It also has the typical 3-way switchable meter for in, out, and gain reduction metering.  What is not so typical is the ability to change the range displayed for the threshold and ratio as well as the max value for the threshold. You can also link attack and release.

The ability to customize the control ranges to suit your style of work and save them in the plug is a fantastic idea that runs throughout the FG-X’s design.  In the settings for the meters you can change the range displayed, needle velocity, and scale for both in/out and separately the gain reduction.  This is great for setting up custom metering if you are doing more precision compression, where a smaller scale is more appropriate than a traditional full view.

FG Comp

The FG Comp sounds great, no color here — just high-quality transparent compression.  I use outboard buss compression, so admittedly I quickly moved on to the reason I wanted to do this review: The FG Level.

FG Level

The FG Level also has four knobs.  The first two, which are labeled as transient controls, are Lo Punch and Detail.

Lo Punch does what you would think, it adds back low end to your mix that might get sucked up from heavy limiting.

Detail makes the perception of the transients a little more clear: You can really dig out some buried hi-hats or snares with this control.

Unlike a lot of mastering-style limiters the FG-X has an additive gain knob, and not threshold and ceiling sliders.  You can set the ceiling on the FG-X, along with your dither options, with a button on the far right.

The final knob is the Dynamic Perception control, which adds back a sense of dynamics without sacrificing level.

Like the FG Comp, there is a Settings button on the FG Level that allows for three customizable meter views; again, I really like this touch.

The final button is the fantastic Constant Gain Monitoring feature, which balances the dry input signal with the output of the FG-X for A/B purposes.

The last control on the FG-Level is the ITP slider.  ITP or Intelligent Transient Preservation is Slate’s special algorithm developed by Fabrice Gabriel.  It is what separates it from all the other plug-ins.  Here’s how Slate describes it:

The ITP slider distinguishes the FG-X’s “Level” panel

“The ITP process uses a complex lookahead detection algorithm to analyze oncoming transients and groups of transients. It then optimizes a specialized set of saturation curves for that specific transient. For example, if the ITP algorithm’s lookahead identifies a kick drum transient, it will optimize the algorithm so that it preserves low frequency energy. For a snare drum transient, it will optimize the algorithm to preserve upper mid range punch. The result is the most transparent means of level maximization the industry has ever heard, with extreme transparency, and no degrading artifacts common to peak limiters.”

The ITP slider controls how hard the transients are perceived in the mix.  On most of my mixes, when the slider was all the way up I noticed slight-to-aggressive distortion. Pulling it all the way down seemed to eliminate that issue on even the most aggressive tasks.

In Use

At the beginning of the mix:

I jumped right in using the FG-X at the start of a mix by throwing it across the bus on an aux track that fed my print track.  I tend to lean to the more aggressive side of mixing, trying to deliver big sounds whether spatial or not, so I’m usually pushing things.  I was really interested to see if the FG-X could carry some of the load that would otherwise be delegated to individual track compression as well as buss compression.

I immediately spun up the gain knob on the FG Level until I began to hear it really break up and then backed it off.  I experimented with different input levels, but I was definitely trying to find a sweet spot so I would be able to back off the bus a bit and get a little more headroom in front of the limiter.

After some use, because I was monitoring through the limiter and hearing the reduced dynamics, I indeed worked the individual tracks and overall buss compression much less.  I instead could focus on level and EQ.  Ultimately, anywhere between 4-6 dB on the gain setting worked well for me.

I really tried to be careful with the Lo Punch control as I am not a fan of global EQ during the mixing stage. However, if I turned up the Lo Punch I could see not having to mess with the bass tracks as much, which could be super-helpful if you need to work quickly and have to have to low end there.  For mastering applications, Lo Punch adds not only great functionality but added value.

When I was mixing through the FG-X, I left Detail and Dynamic Perception off at the beginning.  However I would frequently use them towards the end of the mixing process to tweak. One of the coolest features on the FG Level is the Constant Gain Monitoring button, and I find that this works best if you have the Comp bypassed and are not using Lo Punch, Detail, or Dynamic Perception.

Constant Gain Monitoring is most helpful when adding post mix in a typical mastering scenario, because you can add back those features to compensate for what’s being lost or better understand what you’re adding in without having to manually level match.

The Dynamics panel of the Slate Digital FG-X.

When using the plugin from the start of a mix, I found that while I would readjust the gain control frequently to keep myself honest, it was only over a 1-1.5dB range.  I really loved how it preserved the sense of transients, as I didn’t feel the need to dig out the upper midrange, which can cause some unwanted EQ phase shifting.

After a bunch of mixes all with differing levels of dynamics, including aggressive rock tracks as well as some slower tempo ballads, I was really impressed with how much faster I was working.  All my other dynamic controls didn’t have to work as hard because of the added control of the FG-X, which ultimately led to cleaner mixes.

Prized Predictability

As I mentioned at the start, mixing with the FG-X allowed me to accurately approximate what the final master would sound like.  I was able to focus clearly on what was going to serve that mission, rather than guessing what might translate after mastering.  I could see a future without having to “err on the side of louder” for typical center image parts like kick, snare, bass, and vocals because they would get lowered after mastering – instead, I could now set those parts exactly where I wanted them.

I even had great results mixing through the FG-X and then printing without it, so the mastering engineer could do their thing.  I found that frequently listening to my mixes with the FG-X in bypass gave an informative look into the nature of a how a non-limited mix should sound.  That was the question that started me on this path: Why should I make my mixes sound like a master when they are not yet mastered?

When applying in a more traditional mastering style, I noticed that when there was not a lot of headroom or if the material was quite dynamic, being more conservative was the way to go with all the features.  Lo Punch and Detail came in handy when adding back the low end and cleaning up some of the top end that may have gotten smooshed by over aggressive dynamic controls or decisions made under poor monitoring conditions.

The Dynamic Perception was helpful for something that was already compressed a little too much, but again I decided on conservative use during mixing.  On a few tracks that were less aggressive and/or compressed nicely, I could dig in a little bit more with the all of the controls without getting any bad artifacts.

Final Thoughts

Slate has developed something pretty special here.  The FG-X is the rare plug-in that delivers on its promises, and at only $249 MSRP this is a no-brainer.

It’s not going to be the only tool you need, as it really seems to benefit from proper dynamic control in front of it — though with the FG Comp I could see some mastering jobs not needing much else.  Still, the FG-X provides an essential piece to both mixers and mastering engineers for achieving more control and better results with less effort and resource.

I am still torn between giving the mastering engineer a considerably limited file with headroom and a more dynamic version with which they will have more flexibility, but for the first time I feel that I can deliver a limited file that I can proudly stand behind.  Only time will tell if I appreciate the results of one or the other more.

Whether it represents a slippery slope of taking too much out of the hands of a mastering engineer, or is in fact another tool in their arsenal is probably a subject for another column.  For now, I’m going to continue to think short-term with the FG-X and enjoy better mixes.

Slate Digital FG-X Virtual Mastering Processor:
Mac/Windows VST, RTAS, AU
iLOK Dongle Required

Jason Finkel works between speakers all day in his Brooklyn, NYC mix studio, 4A.  Check his Website for contact/info and follow his new music blog This Music Doesn’t Suck.

  • Great review Finkel! I’d say that mirrors my experience with it quite closely, love the compressor alone on drum busses, has replaced the PSP plugs I was using there

  • Anonymous

    Thanks man…glad you liked the review and the plug.

  • Mike

    Gone are the days when I’m going to pay a mastering engineer. People get these ideas in their heads that they HAVE to use a mastering guy. Why? Does a painter have someone else come in and finish off their painting? Ridiculous right? Well, that’s the mentality that people have with music. Master the dang thing yourself and save yourself a whole bunch of money. You can make your music sound good without a mastering engineer, you really can.