Hello All--
 
I've managed to survive all these years without even knowing about M/S processing, but alas, I've been trying to hone my skills and have read a couple of mixing/mastering books and it sounds pretty cool.
 
I've got a project I'm working on where I have two acoustic guitar parts playing in unison the same part. I would like to use some reverb with the whole M/S thingy to get a real wide, detailed image of the acoustic guitars in this song because they only play during the bridge, etc.
 
I've searched online for any specifics on using Channel Tools with the above application, but I guess I still don't understand the FX signal path to get the reverb effect with the Channel Tool M/S feature.
 
It's probably easy, but when you've never done something before, everything is hard.
 
Any tips are appreciated!

If you have X3 with the Nomad plug-ins, there's a stereo image widener which is super-easy to use.

Craig...would you bus the guitars to a bus with the plug, or add the plug to both guitar tracks individually?  Just curious as to how you would do it.

X2. In my signature ;-)

If you're trying to widen a single track, the simplest place to start would be to turn down the Mid Gain and turn up the Side Gain on the right side.   That should help "spread" the signal by lterally doing what the controls suggest.
 
Or am I missing what you're really trying to do...  

Dear Razor,
 
I know what you are talking about, I don't get this plug-in, too! but don't worry, there are free plug-ins, very easy to use, and effective:
 
M-ST
http://music.service-1.de/html/m-st.html
 
ADT
http://www.vstcafe.com/2010/01/adt-artificial-double-tracking-vst.html
 
have fun - tom

Our sense of width in a mix depends entirely on audible differences between the left and right channels. Without them, we perceive a mono signal panned down the middle. Consequently, the best route to a wide mix involves careful attention to track and effect panning (and using primarily mono tracks). Even if you subsequently enhance the width artificially you'll always get the best results if the mix is already wide to begin with. 
 
There are two kinds of "stereo widening" techniques: artificially creating L/R differences via EQ, delays and phase shifts, and accentuating what differences are already there via M/S processing. There are plugins that can use more than one technique, including the Channel Tools plugin. There are also plugins that utilize M/S processing in conjunction with EQ (e.g. FabFilter Pro-Q, DMG Equilibrium) or compression (e.g. FabFilter Pro-C, DMG Compassion) to enhance width.
 
Basically what you're doing with the Channel Tools plugin (or any other M/S-enabled tool) is separating all the content that's different between left and right (the "S", or Side component) from all the content that's common to both left and right (the "M", or Mid component). If you then boost the former or attenuate the latter, the result is an emphasis on whatever components are different between left and right. It's important to remember that the plugin isn't adding anything, so if your mix doesn't already have some width to it, Channel Tools can't do much to help you.
 
Using Channel Tools is extremely simple: insert it into the fx bin of a stereo track or bus, leave the input mode set to "Stereo" and turn the "MID GAIN" knob down or the "SIDE GAIN" knob up. (I prefer to turn the mid down, to avoid raising levels.) That's it.
 
Channel Tools has some other tricks, too. The delay feature can be used to manufacture some L/R differences where there are none, by delaying one side relative to the other. Just watch out for very short delays, which can cause undesirable comb filtering. BTW, this is how the stereo enhancer in Ozone works, except it's more flexible due to having multiple bands.
 
Beware that often the side component contains much more high-frequency content than the mid, so boosting the sides may also make your mix brighter. In fact, a common cheat is to boost the treble in the sides in order to enhance width even further. Use with caution.
 
Personally, I almost never use Channel Tools or similar plugins for this purpose. If I do any post-mix widening, it'll be via EQ and/or compression (either M/S or simply unlinking a stereo compressor).
 
 

Mid side reverb application is cool if you are into retro or figuring most of your audience is listening in mono, but not all.

I have a video on it in you tube. You can find it by looking through my videos at the link in my signature. I fake the omni microphone for the video with a reverb plug.

Thanks all. I saw a YouTube video on how to set it up and it wasn't real clear, but it looked like (maybe) a separate fx like reverb was being fed into the side chain of Channel Tool.
 
If that's not right, I guess the only way to add reverb in this setting is a reverb plug that has M/S functionality. Is that right?

Razor, you pan the front mike hard left and reverb hard right. When you flip to mono, the verb will exactly cancel. With mid side on, the left track plays left and right in the same polarity. The right track also plays left and right, but the polarity is inverted on the two so in mono I cancels.