#1002889 - 04/29/05 01:36 AM
L+R, L-R, R+L, R-L summing amps
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walters
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Registered: 04/28/05
Posts: 48
Loc: USA
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1.) i wanted a engineer with master faders have
a.) L and R
b.) L + R
c.) L - R
d.) R + L
e.) R - L
2.) What can you do with this stuff?
3.) Is it a spread effect?
4.) How do you use this stuff?
5.) What is the Theory behind this?
6.) Is there more to this then i left out?
7.) I think old stereo in the 70's used this idea
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#1002890 - 04/29/05 11:01 AM
Re: L+R, L-R, R+L, R-L summing amps
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Neil Wilkes
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Registered: 07/06/02
Posts: 514
Loc: London, UK
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L and R is the usual stereo.
L+R is a mono sum, half of the MS process. R+L will give the exact same result.
L-R and R-L should, at least in theory, produce different results but I have yet to see anything that does. It's the other half of the MS process.
Usually, running L-R and then R-L will give you a dual mono result, unless you start getting creative with phase cancellation, and doubling up on tracks.
Not too sure what it is you need to know here - can you please give some details about what you are trying to achieve here?
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#1002891 - 04/29/05 11:29 PM
Re: L+R, L-R, R+L, R-L summing amps
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walters
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Registered: 04/28/05
Posts: 48
Loc: USA
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1.) Yes its used to create phase cancellations
and Doubling up on the tracks
2.) How do i use this stuff to get phase cancellations and doublings?
a.) moving the faders of the L-R and L+R
3.) What is the MS process mean?
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#1002892 - 04/30/05 09:24 AM
Re: L+R, L-R, R+L, R-L summing amps
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Neil Wilkes
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Registered: 07/06/02
Posts: 514
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MS = Mid/Side.
It's basically taking L-R and doing the following math:
(L+R) (L-R) which turns into M-S at that point.
What is the make & model of this amp? It's hard to say much unless I know what you are talking about.
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#1002893 - 04/30/05 01:17 PM
Re: L+R, L-R, R+L, R-L summing amps
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walters
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Registered: 04/28/05
Posts: 48
Loc: USA
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1.) How do i do the math of this L+R and L-R?
2.) What is MS= Mid/Side whats that mean?
3.) The engineer was moving the faders of the
L+R and L-R to get phase cancellations
how did he do this?
4.) Can you explain more about this and the
MS process?
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#1002894 - 05/05/05 07:07 AM
Re: L+R, L-R, R+L, R-L summing amps
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Neil Wilkes
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Registered: 07/06/02
Posts: 514
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http://www.kellyindustries.com/stereo_tools.html
will give you a way to get the M-S splits.
M-S, or Mid/Side, is exactly the same thing as L+R and L-R.
L+R = Mid, or summed
L-R = Side, or one minus the other.
The idea is to turn a stereo file into a different type, which will turn the L channel into Mid, and the R channel into S.
Mid is the sum of left & right, and S is the Side, or the panned information.
There are a lot of plugins that work in M-S mode - see http://www.voxengo.com for some high quality affordable options.
You don't use the M-S to do phase cancellations though.
Can you please explain what you are trying to do??
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#1002895 - 05/05/05 09:16 AM
Re: L+R, L-R, R+L, R-L summing amps
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mudsmith@earthlink.net
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Registered: 10/30/00
Posts: 750
Loc: Martinsburg,WV,UNITED STATES
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M-S, to be more specific, is generally accepted as a stereo micing technique that uses a cardioid or hypercardiod microphone aimed straight ahead (mid), then has a coincident bi-directional (figure 8) microphone (side) aligned to it at ninety degrees, with the positive, front side of this mic aimed to the left.
This does not deliver stereo until you combine the two signals in phase for the left and reverse the phaase of the side mic to combine them for the right signal.
To create the summ and difference M-S matrix with a standard mixer, you would bring the mid mic into one channel and pan it center, you would then bring in the side mic multed to two different channels: one in phase and panned hard left, one reverse phased and panned hard right. For good stereo imaging, these two panned channels need to be even in level....The more these two channels are raised, the wider the stereo image.
The strengths of this technique are strong mono compatability and the ability to adjust the stereo image after the fact by simply recording both mics discreetly and varying the sum and difference in the mix....The technique is still widely used in film, but has not retained as much value in classical music recording as it did initially.
There are some very high end dedicated stereo mics that employ this technique...notably the Neumann (RSM 190?....I'm not sure), which uses a shotgun for the mid mic.
....Simply summing a matrixed M-S signal gives you the mid mic only. Using the left side only gives you the full mix of both mics at whatever mix levels you had established. Both techniques are mono compatible, but the first loses ambience, which can be useful.
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#1002896 - 05/05/05 11:28 AM
Re: L+R, L-R, R+L, R-L summing amps
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BOOKUMDANO
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Posts: 579
Loc: Los Angeles
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Walter's is joking with a bunch of audio forums. Gearslutz, Craig..you name it, he's doing a bizzaro number on everyone.
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#1002897 - 05/05/05 02:52 PM
Re: L+R, L-R, R+L, R-L summing amps
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walters
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Registered: 04/28/05
Posts: 48
Loc: USA
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Bookumbano stop going in my post saying that
why would i be joking
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