I myself am a strong advocate of stereo compression, as long as it is done in a tasteful and thoughtful way.
Stereo compression * (I choose to call it that for simplicity) on the master channel is, in short, about putting a compressor, any really, over the whole mix (often) with the aim of gluing the music together and making it more uniform. Still, it can be about giving the mix a certain type of character or coloring, or creating more movement. Some even go so far as not to compress at all, but only use a certain type of compressor to give the mix that little extra as it is all that is usually so difficult to put your finger on. But basically, stereo compression is about joining all channels in a nice and controlled way, which we will focus on today.
* Refers to stereo bus or mixbus compression.
Which compressor you use plays both a small and large role. By this I mean that virtually all compressors work as stereo compressors, the only question is what you are looking for. Is it about transparent and invisible compression or clear and colored with a lot of character, or maybe something in between? Today there are a plethora of compressors to choose from when it comes to compressing the entire mix, where some of my personal favorites are:
Unisum Mastering Compressor is a brand new universal compressor that has received standing ovations from users. Specially developed for mastering.
The basic settings to keep track of are: Ratio, threshold, gain reduction, attack and release. Depending on the compressor, there are of course more or fewer parameters, but these are the most important current tips today.
When it comes to stereo compression, there is good reason to be restrained and a ratio of more than 2: 1 is rarely necessary. Ration determines how much of the signal compressed when the threshold is exceeded. The higher the ratio, the clearer (more obvious) the compression. Remember that we usually talk about compression that should be felt rather than heard. A more or less subtle joining of the mix, rather than obviously audible compression. The threshold value indicates when the compressor starts working. If the incoming signal exceeds the threshold value, the compressor lowers the volume, based on the prevailing ratio. Applicable attack is the basic rule of not using one too fast and somewhere between 10-30 ms is usually appropriate. In this way, the fast transits are let through while the most intrusive peaks are tamed a bit. The release, which in the event of misuse can lead to the entire mix pumping (which of course may also be desirable), tells the compressor when to stop compressing. Usually you want to use release time of well over 50 ms. It is worth noting that many compressors have so-called “auto release”, which is almost always preferable, although it sometimes has its advantages to manually adjust the release to the music. Finally, we have gain reduction which in short is about how much you compress the sound on your mix. Here, around -1 to -2 dB in the song’s strongest pair is usually appropriate when it comes to compression over the entire mix.
DDMF MagicDeathEye works just as well on individual channels as on the entire mix. The 150 Hz filter is especially nice on the master channel.
Kush Audio AR-1 is based on a tube compressor from the 50’s and is perfect when you want to give the whole mix extra character.
A ratio of 2: 1 with an attack of 10-30 ms and release of over 50 ms (but preferably auto release) and -1 to -2 dB compression is a safe starting point for stereo compression. I usually prefer compressors without a lot of choices, such as MagicDeathEye. This compressor has very few settings and especially a side-chain function, which means that the bottom is compressed less below 150 Hz. A lot of the liveliness and warmth is in the bottom package and if this is compressed too hard, the music loses much of its natural stuns.
With the above in mind, it is important to think about what you actually want to achieve before you throw on a compressor over the entire mix, whether it is light compression, sound coloring or something else. But one thing is for sure: A properly steered compressor can lift your mix both one and two notches.
Feel free to ask questions or comment on the article in the comment field below, and we will spin the topic together. Or if you prefer to discuss mixing in the “Mixing and mastering” section of the Studios forum here!
Fredagstipset is a recurring series where Studio writer Jon Rinneby shares tips every Friday in, among other things, recording and mixing. Here you will find all Friday tips