Audio Mastering using Free Software and Plugins

Here is a tough challenge. Supposing you want to do audio mastering using completely free software and plug-ins; is this possible? This post will not teach you exactly how to master using these free software/plugins but it will show you all the best tools that you can use without spending anything from your wallet and without sacrificing sound quality. This post assumes you are a Windows OS user.

The Audio Mastering Software

First, the most important requirement is to use software with audio mastering capability. This is often hard to find but looking around the web I found Reaper.

This looks promising it says that you can use it for mastering. I am also considering Audacity before but I do not recommend this software for two reasons:

a.) Audacity itself is not recommending the software to be used for audio mastering. See it in their “what you can do with Audacity” page.

b.) I already used Audacity a lot of times in the past and it offers very short previews of the edited clip. If you configure Audacity to use long previews (which is very essential for mastering because you would need to carefully listen to the result of your mastering settings); the program would run very slow.

What other things that should make you consider to use Reaper?

a.) It fully supports a lot of VST plug-ins including those that are designed for audio mastering.

b.) It has a 64-bit internal mixing engine, so it’s fairly accurate and less error free than 32-bit float counterparts when it comes to digital summing. This is important for audio quality.

c.) Although Reaper has a 30-day trial period; it would still fully work after that period (with all features, effects, etc.). So if you are going to entirely use Reaper for free, you can do that. But sooner or later, if you are a happy Reaper user I would recommend purchasing a license. The licensing cost is way too low compared to other software used in mixing and audio mastering.

d.) Reaper has tons of critical features that you can use for mastering. Aside from mastering, you can fully use this software for recording, mixing and even those video-related processing tasks.

So before proceeding further; install Reaper first in your Windows computer. It can take some time to get used with Reaper but they have an outstanding community support that is willing to help every user.

Also you can find the Reaper documentation here. You can also find related documentation related to Reaper here.

EQ in Mastering

The most digital audio music mastering process are as follows: EQ === > Compression === > Limiter. Multi-band compression is also important and could perform both EQ and Compression functionality at the same time. Although you can implement more processing other than the above processes; you can start with just three major steps mentioned. To start with, you need to use an EQ VST plugin. This will be used to shape the sound of your master.

There are lots of great free tools that are available:

1.) Reaper ReaPlugs includes an EQ tool.

This is a parametric equalizer that will let you adjust the sound of your master using the cut/boost values as well as the Q settings. If you are mastering, you should learn the best practices on how to use a parametric equalizer.

2.) Voxengo Marvel GEQ

I am a big fan of Voxengo free plug-ins; one of their EQ plug-in that you can use in mastering is Voxengo Marvel GEQ. Although not a parametric EQ; they have superb accuracy and have a 64-bit internal processing. This is a very handy plug-in for very quick EQ adjustments.

Multiband compressors and Spectral Analyzers

If you want to use a free multiband compressor in your mastering; you can use C3 plug-in. You can read some tutorial here on how to use C3 multi-band compressor. Although the software used is Audacity, you can also run this plug-in with Reaper.

Another great plug-in that you can use for spectral analysis (examination of audio spectrum by visual display) is Voxengo span.

Brick wall limiter/SRC and Dithering in Mastering

Perhaps one of the most important audio mastering plug-in is the brick wall limiter. Luckily there is one great limiter that you can in audio mastering and it is for free.

This plug-in is called W1. It works exactly like the L1 Waves plug-in only that it is free (a clone in functionality). Although the L1 Waves offers more than just the limiter function; W1 works only as a limiter and does not clone the ultramaximizer functionality according to this study.

So now you could not only make your master get that desired loudness but you can make it sound great too.

The last stages in the audio mastering process are dithering and sample rate conversion. The good thing is that you can only one tool for this which is Voxengo R8brain.

Lastly, bear in mind that your ears are still the most important piece of gear in mastering. Use it at all times and do not heavily rely on spectrum analyzers and other visual display to you what settings to make. It is important that you trust your ears.

Reverb- Gverb installation in Audacity

If you have installed Audacity in Ubuntu/ Linux operating system or even in Windows and Mac, you will notice that it does not include reverb effects. For example, if you go to Effects menu in Audacity, you will never see a Reverb effect or even in Effect – Plugin section.

This tutorial shows the installation procedures and basic settings of Gverb and Plate reverb plugin, an open source reverb plugin solution.

Step1.) The very first step is to install the required plugins in your computer. The gverb and reverb plugins are installed via “LADSPA”, otherwise known as Linux Audio Developer Simple Plugin API. If you are using Audacity in Windows or Mac, things are simple. You will only need to download the following installers and then proceed to install the plugin in your computer.

Windows LADSPA installer
Mac LADSPA installer:

Read this tutorial for details for the installation in Windows and Macintosh.

Assuming you are using Ubuntu for your Linux distribution, follow the rest of the steps:

a.) Go to System– Administration – Synaptic Package Manager. Ubuntu requires you to enter your Linux password before you can install anything in your computer.

b.) Under “Quick Search”, type ladspa

c.) Find the package named as swh-plugins, the description of this plugin is: “Steve Harris LADSPA plugins”. Click on it and then select “Mark for installation.

d.) Finally hit “Apply” to proceed with the installation.

e.) The package will then be downloaded and installed in your Linux computer. After installation the package will be marked with a green button as shown in the screenshot below:

Step2.) Now you have installed the required plugins that includes the reverb effects in Audacity. Its time to confirm if those are successfully added to your Audacity installation. Launch Audacity then go to Effect menu. You will notice that not only reverb and gverb plugins are added, the package does include a lot of effects that you can use in your audio production using Audacity. See screenshot below:

Step3.) OK assuming you would like to apply reverb to a sample mixing session in the vocal tracks. According to this mixing vocal tutorial , the most recommended type of reverb for vocal applications are plate type of reverbs. Suggested settings using Plate reverb plugin are as follows:

Reverb time: 1- 2
Damping= 0.35 to 0.45
Dry/Wet mix= 0.30 to 0.5

Remember that these are conservative reverb settings typically applicable for achieving a stronger vocal presence. If you need a long tailed reverb, then simply increase those settings above according to your own choice.

You can read this great guide about Gverb tutorials. Personally I will only use Gverb for adding reverb on non-vocal instruments such as guitars and bass. As a rule of thumb, you should not apply too much reverb if your aim is to attain a high clarity mix. Too much reverb can your mix unpleasant to listen. Set the reverb time not more than 2 to 3 seconds in most cases , adjust other parameters according to the music and be conservative.

Content last updated on June 23, 2012