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Mid Side Processing with Thor

Published: 2017-01-17

Mid Side Processing has become a thing in Reason. Just because of the idea that certain Rack Extensions have opened up the field regarding the concept of M/S Processing or Mid Side Compression techniques. While I have covered a lot of these aspects in the past. In this article I want to share a set up which does not require any rack extensions at all. So any one who has access to Thor the Polysonic Synthesizer can have access to a technique like M/S Processing.

What is Mid Side Processing?

Mid / Side Processing is a technique where you take 2 different signals and blend these together. The signals are:
- Mid : Everything that sits in the Mono Channel of the mix
- Side : Everything that does NOT sit in the Mono channel.

For further reading regarding this concept you can read up on it in a topic called "Mid Side Compression" and in a video I explained the Anansi Mid Side Router.

Mid Side Processing is a technique which is often used to balance the Mono Channel with the Side Channel. At some extend this can also widen up the mix while putting more focus to the side. Processing the mid and the side is often done in the final mix (or Mastering Unit). Since both the Mid and the Side are different channels, it allows the user to Equalize things different on the Mid Channel versus the Side channel or one could compress it different (resulting in to Mid Side Compression).

While there are different Rack Extensions out there which allow you to use this technique, I will just name a few of them:
- Anansi Mid/Side Router
- Red Rock Mid/Side Router
- Synapse GQ-7 Equalizer

There might be others which I might have missed. But these are the one that I know. The first 2 are designed specific to do this task. Synapse GQ-7 can be used in a combination of EQ and Mid Side routing. Hence I am adding this device to the list.

What most people do not realize is that Mid Side Routing can be done by using Thor. The concept is quite simple. We need 2 paths:
- Everything that sits in the mono channel
- And everything that does not sit in the mono channel

Processing the Mid channel

To create a basic Mid Side processor using Thor, we need one device that takes care of the Mono Channel. Normally one would just use the "left" signal of an incoming audio signal. In reason this means that it is automatically "mono". While in terms of setting up the Side, we will be using an effect such as "phase cancellation". There for the direction for setting up the Mono channel might need a bit more work. The Mono channel will look as followed:

Mid Side Processing Reason 5

Inside the programmer we will have to set up the connection for the Audio Left (which is mono) to connect to both the audio output of output one and output two. This is what we will call the mono channel.

Processing the Side channel

For the side, we'll need 2 separate routes. One that cancels out the left side. The other that cancels out the right. For this we'll be needing 2 thor patches to pull this one off.

For left:

Mid Side Processing Left

And for Right:
Mid Side Processing over Right

What we are doing is with this setup is inverting the phase for left while inverting the phase the exact opposite way over right. If you combine those together again you have the Side (everything that does not sit in the mono channel). You could do a similar set up using either Audio In 3 and Audio In 4. But for sake of making it visible what is going to happen I am splitting the Left and the Right in two different Thor Patches.

Thor unite to become MS Processor

Combinator MS Processing

To finalize the Combinator we'll need a three way out. One for the mono channel. One for the Side Left. And one for the Side Right. It is a bit "over kill" that I am doing since in theory you could do the whole thing with mono channels. I know. But from this angle you might see visually how the whole thing gets routed. Since the left and right are the inverted signal, the most important part is to HARD PAN these. If that is not done in this set up you might get some really weird cancellation results in return.

While looking at the front the only part of interest is the mixer panel:

Mid Side Router Thor

For the balance of the Mid / Side there are 2 rotaries. One to balance the Mid and one to balance the Side. It is a different take than using one knob to balance the Mid vs the Side. At some point you could add compressors on the different Thor patches. Equalize the side and the mid different and so.

Anyway. Old topic... just wanted to throw it out there. Here is the patch

Mid Side Processor Thor


Published on Reason Experts
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Published on Reason Experts
Published: 2017-01-17

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