Tutorial: Stereo Width Expansion

There are quite a lot of tutorials out there on making something sound wider. Most involve some kind of phase effect, which are great for harmonic stuff, like pads or leads or vocals. For anything percussive those types of effects mess up transients and can sound a bit odd. What about increasing the stereo width of something complicated like a whole track? You can’t really stick a chorus in a master channel. I came up with a very effective way to increase the stereo width of just about anything in a very transparent way. It’s transparent in the sense that you can set it up in such a way as to increase the presence of the stereo features of a signal without the overall levels of the signal changing much. This is good for master channel applications.

The idea is fairly simple:

1) Split the signal into two components, the mono component (called Mid: the part of the signal that is shared between the left and right signal) and the purely stereo component (called Side: the part of the signal that is the difference between the left and right signal).

2) Use a compressor to increase the average level of the Side component, making it sound louder without its peak level being any higher.

Splitting a signal into Mid/Side is possible out of the box with Ableton, its very simple, just a bit weird.

You need an Effect Rack with two chains in it. Label them Mid and Side. You’re going to stick something in each of these to extract the Mid and Side components out of the stereo signal. First, the Mid chain. This is easy. The Utility plug-in can do this. Just set it’s width to 0.0%.

Next, the Side Chain. This is a bit more complicated. You will use an effect rack inside the ‘Side’ chain. I called it ‘Side Extract’. It will have 2 chains of its own. One called Mid inverted, one called dry. The Utility can’t make a Side signal, only a Mid signal… but if you subtract the Mid signal from the Stereo signal you get a Side signal. So the ‘Side Extract’ Rack has in it one chain that does nothing, called ‘Dry’, and a second chain that has a Utility (width set to 0.0%, Phz-L on, Phz-R on) in it:

After the ‘Side Extract’ rack, stick a compressor. Get it to do a few decibels of compression and you should start to hear a difference. You can leave ‘Makeup’ turned on if you like but this always seems to add a decibel or two gain more than necessary, so I tend to turn that off.

To show the effect I made this recording. In it the effect is turning on and off. In the the ‘Makeup’ setting is on so you can hear a slight gain increase when the effect is on. Thats not what you are listening for though. What’s more important is that it sounds wider.


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