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Re: MS Confusion

Subject: Re: MS Confusion
From: "Tim Nielsen" supernielsen
Date: Sun Jun 3, 2007 8:54 am ((PDT))
Yes that would explain it perfectly, as the MS system isn't designed  
for a S signal that is strong than the M. 100% is the 'widest' stereo  
signal you can achieve without introducing those phase anomalies into  
the stereo.

It will start to sound 'wider' as you increase the S above M, but as  
pointed out, it will quickly begin to sound phasey.


On Jun 2, 2007, at 7:25 PM, scottsherk27 wrote:

> Thanks for all the useful information. (I understand somewhat more,
> but I had the same diffficulty trying to understand bond yields
> curves.) After playing around with some files I have discovered that
> the out-of-phase that I was seeing on Audition's Phase Analyzer
> happens when I increase the S-width in both the MDA and Voxengo plug-
> ins. If I decode at 100% for M and S, the phasing seems fine, but
> registers out of phase with an increase in S. Is this explainable?
>
> Scott
>
> --- In  "John Lundsten"
> <> wrote:
> >
> > Scott wrote
> > > I can't seem to wrap my head around MS and have uncovered a
> confusing
> > > issue. I have discovered that after decoding my MS recordings (MDA
> > > plug-in,Voxengo MSED, or Audition) they are 100% out of phase
> according
> > > to Audition's Phase Analyzer. When I invert one channel, they
> return
> > > into phase. Where in my chain would I inadvertently be inverting
> the
> > > phasing? Or does decoded MS always have an inverted phasing?
> >
> > Not familiar with Plug-ins you mention. The Audition one is/ can be
> rather
> > confusing & its awful to use IMO. Suggest Kelly industries Stereo
> Tools,
> > free & great VST plug.
> > When you say 100% out of phase this suggests mono to me all stereo
> has some
> > out of phase info.
> > Q what does it sound like when you sum the L&R out IE mono it?
> > Q are you using the Phase Analyzer in L/R mode? {not a good idea in
> MS or
> > Spin mode}
> > Q Are you are decoding on the Multitrack page?
> > If you have a 2 chan file running (IE you haven't converted your
> file into 2
> > mono files) the balance control will need to be centered.
> Conversely if
> > using 2 mono files they would need to be panned hard L & R
> >
> >
> > "Tim Nielsen" Wrote
> >
> > > It shouldn't be that way. MS 'should' be completely in phase and
> > > fully mono compatible.
> >
> > Agree 100%
> > >
> > > Are you positive you fed the center mic into the 'left' channel of
> > > the MS plugin, and the figure-8 to the 'right' side? I'm not sure
> > > doing it the other way would cause the phase issues you're seeing,
> > > but they do have to be set correctly.
> > No, that's not it; Actually it would sound surprisingly similar,
> there will
> > be a problem when (if) you mono'd the output however, you would
> only hear
> > the Fig8, IE ambience only.
> >
> > A proper MS decode will send the M to both L&R [same amount/vol, no
> messing
> > with polarity]
> > And the S to both too, but with R getting a phase/polarity flipped
> version
> > of S. [again same amount to both L&R chan but this can be the
> amount you
> > want to get the stereo width desired ]
> > The only way to mess up the phase of the decoder output is not
> follow the
> > above
> > So with a proper de-code if you mono the output the S signal
> cancels ( or
> > the M if you got your M & S swapped/confused)
> >
> > The effect of flipping either M or S on the way in would be ONLY to
> swap the
> > L R sense. There is an assumption or convention that the S mic
> should be
> > mounted with the + phase to the left - if the S mic were mounted
> the other
> > way round all that happens is the stereo field is swapped in a L/R
> sense.
> >
> > >
> > > Are you sure your mic capsules were coincedent? For MS to work
> > > properly, the capsules need to be aligned in the vertical plane.
> > >
> > Reasonable point but it sounds like there's a more drastic prob
> than a
> > slight mangling of the HF phase that would cause.
> >
> > Hope that helps
> > John Lundsten
> >
>
>
> 








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