mid-side encoding matrix

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Member Since: Jul 23, 2004

ok, I've got two mics Behringer B2pro and GrooveTubes GT55.. I understand that I might get a nice recording using a mid-side technique: GT55 as mid and B2 for sides. I understand that for this to create a stereo image I need a mid/side encoder.
Software is not an answer for me as I am recording into a harddisk machine.. Yamaha AW16.
I understand that this technique is quite old (1940's?) so.. is there a way to accomplish this using old fashioned technique like panning and/or phase switching?

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Administrator
Since: Apr 03, 2002


Jun 01, 2006 08:33 am

If you have one mic on each side of the room, just pan the track they go to differently.

Member
Since: Jul 23, 2004


Jun 01, 2006 09:47 am

I'm talking about the technique of two mics .. one a cardioid aimed at basically the center of your sound source.. then directly behind (like a bundle) a figure eight mic facing so that that mics pickup lobes are facing to the left and right. In other words, the cardioid sits in the rejection zone of the figure eight.. sort of a bundle picking up in three directions.
However, according to the GrooveTubes manual, I need a "mid/side stereo matrix line encoder" to create a stereo image. But this being an old idea from the 40's there must be, I am thinking, a way to use cables and board to divide the positive and negative sides of the figure eight and correlate them to the cardioid mid properly. Unfortunatley the manual only tells which piece of GT gear I need to buy to make this happen.

Member
Since: Jul 23, 2004


Jun 01, 2006 09:49 am

PS.. using this technique allows you to use two different mics to get a " very accurate stereo image" as opposed to needing a matched pair.

Administrator
Since: Apr 03, 2002


Jun 01, 2006 09:51 am

Hmmmm, well, I would have to say that if you are using two mono microphones in the center of your sound source and plan to rely on the figure 8 pattern to pick up the stereo sides, you are likely in for a frustrating experience...it's still a mono microphone.

The way I see it is to just split the mono signals to two tracks and apply different reverb and/or EQing to each side to create a sort of stereoish sound.

But, never having heard of that technique before I cirtainly can't speak with any authority on the subject...

I am not a crook's head
Member
Since: Mar 14, 2003


Jun 01, 2006 10:05 am

Here's a little wikipedia action on the subject:

www.wikirecording.org/Mid...phone_Technique

Interesting technique, but it still looks like it uses just 2 mono signals in the end.

I learned something today!

[edit]
OK I actually read down further...you copy the figure-8 mic's signal, paste to another track, and reverse its phase. Then pan one hard left, one hard right. Then use the level of the center mic (panned center) to affect the stereo "width" of the image.

Hold 'Em Czar
Member
Since: Dec 30, 2004


Jun 01, 2006 10:13 am

nagh db it's a legit technique, you can make your own matrix by copying the routing as follows

track 1 is mid (mono)
track two is figure 8 panned hard left
rack three is a copy of track 2 panned hard right with the polarity flipped 180 degrees

the really cool thing about this technique is you get TOTAL mono compatability (the sides cancel eachother out) and you can control the width of your stereo image (with panning of the other two tracks.

no matrix is needed

also you can use this same technique durring mastering to 'isolate' the center channel (say you wanna mess with the vocal, kick, and snare only. or vice versa

Member
Since: Jul 23, 2004


Jun 01, 2006 10:52 am

Excellent! No need to purchase an encoder/weather pylon.
But, by the drawing in the WikiLink, I am thinking that I am probably better off to have my figure eight B2 on the bottom (top up) and my GT55 directly above (bottom up) to get closest to "best case scenario".. that is to get the mic pickup as close to eachother as possible.. instead of my first description.. that is one behind the other. I'll try both though.

*sticado: short and LOUD!*
Member
Since: Feb 25, 2005


Jun 01, 2006 02:49 pm

so its like having 2 of the same mics doing an XY and moving their direction closer or farther from eachother, but instead u dont need the same mics. u can control the stereo image by the volume of the Mid mic? is that right? cuz thats freakin sweet.

*sticado: short and LOUD!*
Member
Since: Feb 25, 2005


Jun 01, 2006 02:50 pm

oh and they arent XY... they just make that same function.

Hold 'Em Czar
Member
Since: Dec 30, 2004


Jun 01, 2006 04:18 pm

yeppers, and you can also manipulate the stereo image by not pannin' the sides hard L&R, or turn down the volume of the sides some for a more 'centered' sound that's still stereoized...it's a handy setup,

and it's more like an ORTF (spaced pair) type of setup instead of xy....

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