Decoding Mid-Side Recording at DVinfo.net

David Ennis · January 22nd, 2006, 02:45 PM

Does Adobe Audtion decode or encode (whichever is correct terminology) a mid-side recording to stereo?

Are there any other programs or plugins that do?

Seth Bloombaum · January 22nd, 2006, 03:54 PM

If Audition can accomodate VST plugs, try this freeware decoder:
http://www.voxengo.com/downloads/?highlight=msed It works fine. Look for the highlighted plugin called "MSED".

But you might be able to build a decoder without plugins. I'm not familiar with Audition but try this:

Assuming that the cardoid/mid/mono element is on the left channel.

Make a total of 3 copies of your stereo recording on your timeline.

Track 1 - Left channel of the recording, pan center.
Track 2 - Right channel of the recording, pan left.
Track 3 - Right channel of the recording, invert phase and pan right.

If you have a way to group/lock the volumes of channels 2 & 3, do it. Stereo spread will be changeable by the relative volumes of Track 1 to Tracks 2&3.

If it's not sounding right, pan Track 2 right and Track 3 left. But if the wiring was right when recorded you won't need to do this.

This all represents the Mid-Side decoder formula:
Left = M+S
Right = M-S

It's really kind of magic...

Barry Werger · January 22nd, 2006, 05:42 PM

I don't know anything about Audition... but you can also do the same thing Seth recommends by bussing the signals (instead of copying the tracks), which will be easier to manipulate and use fewer system resources if it's a concern. This also lets you monitor live in stereo rather than MS if you have your DAW along...

So: Assuming you have two mono tracks, "M" and "S" and aux busses 1 and 2:

Just send M panned center to your main outputs;
Send S to both bus 1 and bus 2
Invert bus 2
Send Bus 1 to Main Left and bus 2 to Main Right.

Now, you can just use the M fader to control volume and the S fader to control the width of the stereo image.

Again, I don't know if this all works in audition... but for anyone with ProTools or another systems that allows bussing, I think this has some advantages.

-Barry

P.S., I do a lot of MS recording, and I find it's always a good idea to record a test where you just walk from left to right in front of the mic, saying "Left... center... right" appropriately. This lets you very quickly make sure you've got everything properly set up in post.

David Ennis · January 23rd, 2006, 08:50 AM

Of course! I should have been able to figure that out, but I may never have. Thank you, gentlemen.

Roger Averdahl · January 23rd, 2006, 11:26 AM

Or, go to Effects > Amplitude > Channel Mixer and choose the Preset Mid-Side o L-R in Adobe Audition.

/Roger

January 22nd, 2006, 02:45 PM	#1
David Ennis Fred Retread Join Date: Jul 2004 Location: Hartford, CT Posts: 1,227	Decoding Mid-Side Recording Does Adobe Audtion decode or encode (whichever is correct terminology) a mid-side recording to stereo? Are there any other programs or plugins that do? __________________ "Nothing in the world can take the place of persistence..." - Calvin Coolidge "My brain is wired to want to know how other things are wired." - Me

January 23rd, 2006, 08:50 AM	#4
David Ennis Fred Retread Join Date: Jul 2004 Location: Hartford, CT Posts: 1,227	Of course! I should have been able to figure that out, but I may never have. Thank you, gentlemen. __________________ "Nothing in the world can take the place of persistence..." - Calvin Coolidge "My brain is wired to want to know how other things are wired." - Me

January 22nd, 2006, 03:54 PM	#2
Seth Bloombaum Inner Circle Join Date: Sep 2003 Location: Portland, Oregon Posts: 3,420	If Audition can accomodate VST plugs, try this freeware decoder: http://www.voxengo.com/downloads/?highlight=msed It works fine. Look for the highlighted plugin called "MSED". But you might be able to build a decoder without plugins. I'm not familiar with Audition but try this: Assuming that the cardoid/mid/mono element is on the left channel. Make a total of 3 copies of your stereo recording on your timeline. Track 1 - Left channel of the recording, pan center. Track 2 - Right channel of the recording, pan left. Track 3 - Right channel of the recording, invert phase and pan right. If you have a way to group/lock the volumes of channels 2 & 3, do it. Stereo spread will be changeable by the relative volumes of Track 1 to Tracks 2&3. If it's not sounding right, pan Track 2 right and Track 3 left. But if the wiring was right when recorded you won't need to do this. This all represents the Mid-Side decoder formula: Left = M+S Right = M-S It's really kind of magic...

January 22nd, 2006, 05:42 PM	#3
Barry Werger Regular Crew Join Date: Jan 2006 Posts: 104	I don't know anything about Audition... but you can also do the same thing Seth recommends by bussing the signals (instead of copying the tracks), which will be easier to manipulate and use fewer system resources if it's a concern. This also lets you monitor live in stereo rather than MS if you have your DAW along... So: Assuming you have two mono tracks, "M" and "S" and aux busses 1 and 2: Just send M panned center to your main outputs; Send S to both bus 1 and bus 2 Invert bus 2 Send Bus 1 to Main Left and bus 2 to Main Right. Now, you can just use the M fader to control volume and the S fader to control the width of the stereo image. Again, I don't know if this all works in audition... but for anyone with ProTools or another systems that allows bussing, I think this has some advantages. -Barry P.S., I do a lot of MS recording, and I find it's always a good idea to record a test where you just walk from left to right in front of the mic, saying "Left... center... right" appropriately. This lets you very quickly make sure you've got everything properly set up in post.

January 23rd, 2006, 11:26 AM	#5
Roger Averdahl Major Player Join Date: May 2005 Location: Stockholm - Sweden Posts: 344	Or, go to Effects > Amplitude > Channel Mixer and choose the Preset Mid-Side o L-R in Adobe Audition. /Roger