How to Master With Free Plugins

How to Master With Free Plugins


When mastering with free plugins start with subtractive M/S EQ to attenuate the side’s lows and a little of the side around 2kHz with a bell.  Then saturate the mid and side separately, expand the stereo image, clip, and end the chain with a limiter.

Start with M/S EQ

The steps in the video are in order, and each subsequent processor is part of a mastering chain.

The first thing I’m going to do is insert an M/S equalizer – I’ll use the MEqualizer by Melda audio, and in the output, settings change it to Mid and Side processing. Then I’ll create a band, right-click to open up the settings and change it to the side image.

I’m going to make a high pass, and move it up to about 70Hz to attenuate low side frequencies.  This will make my kick and bass more mono and focused.

Additionally, I’ll create a bell filter on the side, and attenuate around 2.5kHz – this will help the mids of the vocal cut through.

Let’s take a listen and keep in mind the effect will be subtle.

OTT for Upward Compression

If used subtly, OTT can work well for mastering – I’m going to turn the depth, upward and downward dials to 0%, and drag all the bars in the middle to the right.  Then I’ll set upward to about 10%, and slowly increase the depth dial until I notice amplification.

A little goes a long way with this plugin, so let’s listen to it with some aggressive settings, but then scale it back.

GSAT+ on Side Image

What’s cool about this free plugin is that you can saturate different aspects of your image – so I’ll first saturate the side image which will amplify it, and cause mild stereo expansion.  Using the monitoring section up top I can solo the side, and then dial in the settings.

There’s no exact correct setting here, you just have to find what sounds best for the mix.  Since we’re mastering, it’s best to enable some oversampling to avoid aliasing.

Let’s take a listen to the subtle changes this makes.

GSAT+ on Mid Image

Let’s use the same plugin as the last chapter, but this time, saturate the mid image – again we can monitor only the mids by selecting it up top.  I’ll use a different saturation setting and varying harmonic amounts to help differentiate my mid-image saturation from the side.

Again, oversampling is needed to avoid some unwanted aliasing distortion.  Let’s take a listen.

Expansion with Stereo Helper

We have some options for free stereo expanders, but I like Stereo Helper since it lets me adjust the balance between the mid and side image.  Additionally, I can monitor these changes, quickly preview my mid and side image, and test mono compatibility which is helpful.

The only function I’ll use is the side gain, which I’ll amplify slightly.  Alternatively, you could leave the side along, and subtly attenuate the mid. 

Let’s listen with aggressive settings and then bring the side image down to a reasonable level.

Additive M/S EQ with Overtone

Next, I’m going to use an EQ to add more of what I like to the signal – with the Overtone GEQ by Voxengo, I’ll first switch the processing to Mid and Side, but this is optional.  On the mid, I’m going to boost a little of the kick’s fundamental.

I’ll also dip some of 350Hz, bring the vocal forward a little with the 2kHz slider, and adjust the frequency to best match the vocal’s presence range.

On the side, I’ll boost a little of the low mids around 400Hz, which sounds better on the side than on the mid.  Then I’ll boost the highs to add some air.

This plugin also introduces mild harmonics, so I like to include oversampling.

Let’s take a listen.

Free Clipper Option 1

Clippers are helpful if you want a loud sound, but don’t want to use your limiter too aggressively, since a limiter is going to reduce the impact of your transients.  Cymatics Diablo Lite is a good clipper, so I’ll set the clipper to hard, and subtly increase the value.

I’d avoid the punch mode since it doesn’t work too well on a master.  Let’s take a listen to how this hard clipper increases loudness and helps augment transients.

Free Clipper Option 2

If you want some various clipping shapes, Free Clip by Venn Audio is another good option.  Increase the input gain until clipping occurs which can be observed when the waveform turns red, change the clip type, adjust the clip ceiling, and enable oversampling to again avoid aliasing distortion.

I like to lower the output of mine a little bit as well.  Let’s take a listen and know that after this demonstration, I’m going to be using the cymatics clipper instead of this one.

Free Limiter Option 1

We also have some free options for limiters – first, let’s try out limiterOne by CIS DSP which I find retains the transients but introduces a little bit of unwanted pumping at higher levels, at least with this mix.  I’ll set the release to 200ms since that’s not too quick to distort.

Also, I’ll lower the ceiling a little to avoid inter-sample peaking – something this limiter is surprisingly good at avoiding.  Let’s take a listen.

Free Limiter Option 2

LoudMax by Thomas Mundt is another popular free limiter – it works like the Wave L1, in which you simply reduce the threshold to enable both limiting and auto-make-up gain.  This has a smoother and warmer sound with less pumping but I think I’m hearing some added distortion.

Let me know which limiter you preferred in the comments.

Monitoring with ISOL8 and YouLean

Last up I’m going to monitor the signal, first by using ISOL8, which I’ll insert before my limiter.  I’ll solo specific frequencies, and monitor the mid and side, just to make sure everything sounds the way I want it to – then I’ll remove the plugin.

After the limiter, I’ll insert the free version of the Youlean Loudness meter to check my LUFS, which I want somewhere between -14 LUFS and -9 LUFS.

After that’s been measured I’ll remove it from the chain as well.

Let’s take a listen to the before and after, using some gain compensation on the before part to better understand the differences.

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