Alright, here's my first serious PD patch. This basically does the same thing that the srs-wow effect does in windows media player as well as the srs-iwow effect in itunes. (considering srs-wow used to be a licensed product that people had to pay a large amount of money to license, this was stupidly easy to recreate...)

Artificially increases the depth and width of a stereo track (will not work on mono tracks).

It sounds pretty nice!

How this works: Essentially we are taking a stereo track, converting it to a mono stream, inverting it, and rendering it mixed with the stereo track again. I figured this out from a friendly user over at the audacity forums here: http://goo.gl/EfLTIf

Just click the bang, open a wav file and hit start!

Download Here:
Stereo_Butterfly.pd

EDIT: Also, I'm pretty sure its safe to say this file can be licensed as Public Domain.

This is usually called "mid-side processing", and not patented at all. You can get MS tracks from LR very easily.
M = (L+R)/2
S = (L-R)/2

@dwan Huh, TIL.
Well, thanks for letting me know.

Where did it's name originate from?

@TerraByteTech It is Middle and Side from a microphone setup that you will find more about here..... http://ehomerecordingstudio.com/stereo-microphone-techniques/ (No.5)
It gives a stereo feed, but with true mono compatability and so was used a lot for television and radio in the good old days........
David.

@whale-av Thanks you guys!

@TerraByteTech And I'm not so sure about the patent........ http://www.google.co.uk/patents/US5661808 ....... I seem to remember Roland made an effect unit when delay chips became affordable. In America it is fairly easy to patent someone else's (already published) idea.... but I don't know for how many years they are valid..... yes I do...... 20 years for a patent filed after 8 June 1995.
David.

@TerraByteTech I got some pretty heavy bass distortion when I tried this. Do you know why this might be? Maybe a signal divide is needed?

@LiamG what are you listening to it through? This is primarily meant for basic headphone setups.

I'm using headphones. I made a direct comparison between this patch and the raw output from readsf~, and the kick drum sounded distorted when using the effect.

@LiamG weird..
Would you mind uploading the wav file in question (or at least one that displays the same effect)?

@TerraByteTech I have not listened to this, but I think the butterfly effect must be producing a "fake" widening of the stereo induced in ones brain by a phase difference. We judge the position of a sound in the stereo field by phase difference, but our brains are not able to do that at low frequencies, and sources like bass guitar and kick drum should really stay mono....
Maybe you should just add a [hip~] and maybe only to the LR ("side") source?......to preserve a bass signal "centre stage" (on the "mid")..........
David

@whale-av

I have not listened to this, but I think the butterfly effect must be producing a "fake" widening of the stereo induced in ones brain by a phase difference.

that is correct

Maybe you should just add a [hip~] and maybe only to the LR ("side") source?......to preserve a bass signal "centre stage" (on the "mid")..........

You are welcome to give it a shot! I might try it out later, but I'm still learning how Pd works in the first place. My knowledge of digital audio programming is still very limited.

I don't want to upload it because my internet connection is awful and plus I think it is copyrighted, but you should be able to download the track here:

You won't miss the distortion I'm talking about--it starts with the bass drum. Compare it to the raw output and you'll see.

While we're here, I might as well make an off-topic plug for Deepchord's music! His releases on Soma are sublime.

Here is my take at a proper MS mixer. If you make S slightly louder, it'll feel a bit wider. Also try to mute M on classic rock music to make the lead singer disappear
M-S mixer.pd