Shadow Hills Mastering Compressor Plugin Review

Some people say that the Shadow Hills mastering compressor looks overly complex. The first thing that you have to realize is that while it can operate in Dual Mono, there’s a switch to put it in Stereo. That means all the knobs on the left will control the left and right stereo output. So I’m going to go ahead and cover up the controls on the right. Poof! Complexity reduced by half 😉

Shadow Hills Mastering Compressor Plugin with Half the Controls
Shadow Hills Mastering Compressor Plugin with Half the Controls

Optical Compressor

The next thing to realize is that this amazing compressor is actually 2 compressors in one. An Optical and a VCA. That’s right, a two for one deal!

As an aside, the hardware unit by Shadow Hills Industries isn’t much more than the price of an LA-2A and an 1176. If you figure that the Shadow Hills Mastering Compressos is a stereo unit, you’d have to buy two LA-2As and two 1176s. The Shadow Hills starts to look like a bargain.

The first section is the optical compressor. It has two knobs, an “Optical Threshold”, which is the point at which it kicks in, and an “Optical Gain”. While there is no ratio knob, there is as fixed ratio of 2:1. Ideally you want to turn the Threshold to “tickle the needle” as the great Al Schmitt would say, or do about -1db of gain. (Make sure the Meter Select is set to Optical so that the meter will show the gain reduction.) Then turn the Optical Gain up to match what it sounded like with the unit off. You do this by flipping the Optical In/Out button back and forth until the sound level matches (by ear not visually.)

 Do you know how to work an LA-2A? (I hope so, there's only 2 knobs!)  Then you know how to operate half of the Shadow Hills.
Do you know how to work an LA-2A? (I hope so, there’s only 2 knobs!) Then you know how to operate half of the Shadow Hills.

Discrete Compressor

The next section is the VCA. Just like the optical section, it has a knob for Discrete Threshold and a knob for Discrete Gain. Additionally, it has knobs for “Discrete Attack”, “Discrete Recover” and “Ratio”. On the Recover knob, “Dual” means that the recovery will mimic the optical recovery, which is a two stage process. There is also a “Sidechain Filter” toggle, which filters out any frequencies below 90 Hz so that low end sub frequencies won’t create pumping. To use it as a limiter, you can set the Ratio to Flood, which means 20:1.

For Mastering purposes, you’d probably most often leave this at 1.2, with a long attack and short recovery. However, if you’re looking for more of a pumping effect, you could start with an attack of 1 or 5 and a ratio of 3, and play with the recovery until it’s in time with the beat. And there’s no rule saying that you can only use this for mastering.

The VCA section adds Attack, Recover and Ratio, and can be used as a Limiter by setting the Ratio to Flood.
The VCA section adds Attack, Recover and Ratio, and can be used as a Limiter by setting the Ratio to Flood.


The final section is where you get to pick the transformers. You can pick Nickel, Iron, or Steel, and from an engineering standpoint I love this idea. Iron adds in even-order harmonic distortion (some say it gets you that Neve sound.) Nickel is the cleanest sound, which some compare to the older Jensen type sound. Steel adds the most distortion.

Unfortunately, I’ve found the transformers options in the plugin to be subtle at best. I think with modern listening environments (the masses streaming to tiny speakers) there isn’t going to be much benefit from this. If you’re looking to add distortion and harmonics check out our article on better ways to do this.

The little circular green light is mostly just to make it look cool. It dances with the output level.

The transformer section lets you pick between Nickel, Iron and Steel
The transformer section lets you pick between Nickel, Iron and Steel


Now let’s run through a few of audio examples. These were gain matched by ear, so there shouldn’t be much volume bias to make the Shadow Hills sound better by being louder.

On these drums you can hear it pull the room out a bit more when enabled.

Drums – Dry
Drums – Wet

For this clip of a piano and cello, the Optical section is trimming 1 db on the harder piano hits. The Discrete section is set to Flood to act as a limiter, with a fast recovery of .1 and an attack of 1. The neat thing is that every time the Optical trims a db, the Discrete trims a db as well. Sometimes though, the piano sneaks through the Optical, and the Discrete catches it and trims half a db.

Piano and Cello – Dry
Piano and Cello – Wet

Here are the same clip, but with a bit more dynamics. The “Buss Medium” preset is used to tame the more dynamic parts.

Piano and Cello with Dynamics – Dry
Piano and Cello with Dynamics – Wet

For this EDM -ish clip, the claps are panned 3 o’clock right and the hats 9 o’clock left. The panning effect is a bit more apparent with the compressor in Dual Mode.

EDM type sample – Dry
Sample with Shadow Hills Dual Mono Applied

The resource efficiency on the Shadow Hills Mastering Compressor plugin is really good. Here’s what only one instance looks like, using just 6% DSP. It was 5% DSP with no plugins It seems like each instance adds about one percent.

One instance of Shadow Hills running
One instance of Shadow Hills running

Curious to see what the resources looked like, I put one one on each track, plus the mix bus (for a total of 5) and used just presets. The DSP only hit 12%!

Alternatively, If I put an LA-2A and 1176 on five tracks to emulate the serial chain of the Shadow Hills, that clocks in at 16% DSP. So if you often run the LA-2A/1176 serial compression chain, you may consider trying the Shadow Hills instead.

Now I know some of you will say the 1176 is a FET, not a VCA. But what is a good test instead? An LA-2A into an API 2500? On 5 tracks, that hits 39% DSP. An LA-2A into an SSL Legacy Channel Strip? On 5 tracks that hits 25% DSP, and that’s a really weird chain.

Five instances running with presets only hit 16% DSP.
Five instances running with presets only hit 16% DSP.
Sample dry
Sample with 5 instances of Shadow Hills

As an aside, if you aren’t an Apollo owner and don’t need an interface, but you are still interested in running UAD plugins, be sure to check our article on the UAD Satellite Octo.

Should I Get It?

So would I recommend getting the Shadow Hills plugin? I would. This is one of the go to plugins on my mix bus. Not only is the plugin a fraction of the price of one of the premiere mastering hardware compressors, it’s also resource efficient. Imagine what it would cost to put the hardware unit on every track! Shadow Hills is one of the best UAD plugins!

If we were talking hardware, then I’d probably recommend the API 2500 first since it’s a stereo unit too, and it’s less than half the price of the Shadow Hills. Since these audio plugins are comparably priced, that argument goes away.

While it can pull double duty as an LA-2A replacement, you probably already have an LA-2A that came with your hardware. If you don’t have a VCA compressor plugin, then this might fill that hole.

If you are feeling pretty good with the compressors you have, don’t let the cool interface sway you. There may be more important plugins that you need first (do you have 3 types of EQ and 3 types of reverb?) If, however, you are feeling like you have pretty good coverage with your other plugins, then it’s unlikely you’ll regret adding this to your arsenal.

UPDATE: Up to this point, The Shadow Hills Compressor Plugin was only available as a UAD plugin, but now Plugin Alliance offers it as well, so be sure to check out our UAD plugin reviews and our Plugin Alliance reviews.

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UAD Shadow Hills Mastering Compressor Plugin
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