Fascinating MS

[Gary Eickmeier]

Playing with MS more lately to solve another problem, and getting some
pretty amazing results. You may remember that I always listen in surround,
and I have always sought a very wide and spacious sound. What I have found
is that if you set the S channel just right (about +2 in my case) you can
just about achieve surround sound for free. I got a new MS module for my
Zoom H6, so I went to try it out on my jazz band that I record. The stereo
call out test went almost perfectly, the soundstage spread evenly and
perfectly across the entire width of the room, but a bonus was when someone
else talked or played something during the test I heard them placed very
accurately where they were actually sitting, front or rear, left or right.

Additionally, it seems that MS is able to encode direction more accurately
and finely than any other miking technique or scheme. I have tried. The
ability to adjust the stage width afterward is a bonus that shouldn't be
discounted.

Along with that, I am wondering what the Stereo Width Control is doing in
Audition is doing exactly - is it converting a normal stereo signal to MS
and back again? Or is it just extracting some middle and making the
difference signal greater?

Gary Eickmeier

[Scott Dorsey]

Gary Eickmeier > wrote:
>Playing with MS more lately to solve another problem, and getting some
>pretty amazing results. You may remember that I always listen in surround,
>and I have always sought a very wide and spacious sound. What I have found
>is that if you set the S channel just right (about +2 in my case) you can
>just about achieve surround sound for free.

That's because the S channel decodes almost completely to the rears.
The thing is, as something moves right to left across the soundstage, it
will also move forward and back at the same time.

>Additionally, it seems that MS is able to encode direction more accurately
>and finely than any other miking technique or scheme. I have tried. The
>ability to adjust the stage width afterward is a bonus that shouldn't be
>discounted.

Decoded MS and coincident cardioids are mathematically identical and they
are very close to interchangeable with top-grade microphones. As you get
to cheaper microphones that are less flat off-axis, the X-Y configuration
becomes more of an issue since the center of the soundstage is off-axis on
both mikes.

>Along with that, I am wondering what the Stereo Width Control is doing in
>Audition is doing exactly - is it converting a normal stereo signal to MS
>and back again? Or is it just extracting some middle and making the
>difference signal greater?

There is no difference between these two processes. They are identical.
Both basically come down to increasing the L-R component.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Frank Stearns]

"Gary Eickmeier" > writes:

-snip-

>Additionally, it seems that MS is able to encode direction more accurately
>and finely than any other miking technique or scheme. I have tried. The

You haven't tried 50 cm A/B with diffraction spheres, then (or perhaps the Jeklin
disk, which I have not tried).

MS has okay L-to-R imaging. But sometimes the LR soundstage "dimension" can be
non-linear the further left or right you go. That is, you can have a somewhat
clustered "centerish" soundstage that then suddenly zips out to far left and far
right. Farther center left and farther center right can kinda be skipped over to
jump directly to that far left and or right. Doesn't happen all the time, but it
can.

Aside from not having a reliably accurate left-to-right, my main complaint with MS
and XY is the lack of true, pin-point, *front-to-back* imaging. That's why I largely
abandoned MS when I heard 50cm A/B. That, and the ability to use omnis which,
because of their much better low end response and more even response in general,
brought on a whole new world of realism, particularly with orchestral work.


>ability to adjust the stage width afterward is a bonus that shouldn't be
>discounted.

Typically, you don't want to do that with A/B because that's where the "room width"
lives, and rarely is your "subject" as wide as the left and right walls. But if you
want you can trim in the pan pots a touch to narrow the image and you'll do no harm.

>Along with that, I am wondering what the Stereo Width Control is doing in
>Audition is doing exactly - is it converting a normal stereo signal to MS
>and back again? Or is it just extracting some middle and making the
>difference signal greater?

Several plug-ins have a width enhancer. Generally that's done by crossfeeding delay
components or similar time-based trickery. Indeed it's handy -- if not overused.

Now, there are some mastering processors that convert to and from a pseudo MS so
that you can then raise or lower the center of the image, but I'm not sure it's
truly MS. For one thing, as I understand these (have not used one), you do not
change the width as you adjust the "center" volume. YMMV.

Frank
Mobile Audio

--

[Peter Larsen[_3_]]

"Frank Stearns" > skrev i en meddelelse
...

> "Gary Eickmeier" > writes:

> -snip-

>>Additionally, it seems that MS is able to encode direction more accurately
>>and finely than any other miking technique or scheme. I have tried. The

> You haven't tried 50 cm A/B with diffraction spheres, then (or perhaps the
> Jeklin
> disk, which I have not tried).

I actually think my best spatial rendering is an AB recording made like that
with the microphones parallel. It was also the last time I changed a setup
in the intermission, an old tape amateur friend, how had asked me to help
him with the recording, suggested I should angle the CK22's outwards and it
caused a collapse of perspective that was so annoying that I only ever
burned the first part to CD.

I also made a number of AB recordings in August 2014 because it allowed a
less visually obtrusive setup, something that was specifically requested by
the event photographer, a couple of them with CK22's but most of them with
Sennheiser MKH106 and all of them with the mics positioned vertically. That
setup of course required a treble boost in post ... O;-) ... but worked like
a treat with mics only 2 meters above the floor.

For deep ensembles, such as those with a concert grand I added an other omni
on the piano, often but not always only one. Stereo miking of a concert
grand for spot miking is grossly overevaluated and often causes more stereo
problems than it solves, I trust the main pair to deliver the stereo image
and just use the spot mic(s) - suiably delayed - to add focus.

> MS has okay L-to-R imaging. But sometimes the LR soundstage "dimension"
> can be
> non-linear the further left or right you go. That is, you can have a
> somewhat
> clustered "centerish" soundstage that then suddenly zips out to far left
> and far
> right. Farther center left and farther center right can kinda be skipped
> over to
> jump directly to that far left and or right. Doesn't happen all the time,
> but it
> can.

> Aside from not having a reliably accurate left-to-right, my main complaint
> with MS
> and XY is the lack of true, pin-point, *front-to-back* imaging. That's why
> I largely

Enter what I also call xy - it is more misleading to call it ortf - namely
some 12 to 22 centimeters capsule spacing and an angle between the
microphone in the 45 to 100 degrees range, smaller angle if you are close or
it is a wide ensemble, larger angle if you are further away. Adjust inter
microphone angle for stable center and - my preference - a bit of room on
the outside of the ensemble, just like the real world is. Under some
circumstances a pair of omnis tend to blur far away sound sources in a very
reverberant room, and then the image compensation abilities of a spaced xy
pair can be most helpful.

> abandoned MS when I heard 50cm A/B. That, and the ability to use omnis
> which,
> because of their much better low end response and more even response in
> general,
> brought on a whole new world of realism, particularly with orchestral
> work.

Omnis are kinder to any kind of transient than cardioids, it did not take
long to learn than when using a MD211 together with a pair of MD4241's. And
oh what imaging problems one can have when the helpful electronics guy who
soldered mic cables for you can not read a Sennheiser cable spec properly
and miswires the HL ... thinking back I still think that was way too uphill
a way to start recording ... :(

>>ability to adjust the stage width afterward is a bonus that shouldn't be
>>discounted.

> Typically, you don't want to do that with A/B because that's where
> the "room width" lives, and rarely is your "subject" as wide as the
> left and right walls. But if you want you can trim in the pan pots
>a touch to narrow the image and you'll do no harm.

Don't worry, forget theory and take it to ms and fix it and back, adjusting
the S level is a good way to strengthen the center and if you have too much
reverb then it also is likely to be helpful to eq the S signal. However
using diffraction spheres does just about "all of that", something that
needs to be understood. And it works in three dimensions, eq works globally.

>>Along with that, I am wondering what the Stereo Width Control is doing in
>>Audition is doing exactly - is it converting a normal stereo signal to MS
>>and back again? Or is it just extracting some middle and making the
>>difference signal greater?

> Several plug-ins have a width enhancer. Generally that's done by
> crossfeeding delay
> components or similar time-based trickery. Indeed it's handy -- if not
> overused.

It is an MS tweak, but I've always preferred to make those manually.

> Now, there are some mastering processors that convert to and from a pseudo
> MS so
> that you can then raise or lower the center of the image, but I'm not sure
> it's
> truly MS. For one thing, as I understand these (have not used one), you do
> not
> change the width as you adjust the "center" volume. YMMV.

The simplest ploy to fix a troublesome recording is usually the best. But we
are seeing a lot of plug ins coming on to the market that a) do what most
daw software can do out of the shrink wrap and b) capitalizes on user
ignorance by offering to make the "difficult bits" as if MS was something
exotic. It is akin to when Symantec sold Norton Tools for windows that
basically just did what the OS could do anyway. That said, some of the time
a plug in can offer a very neat short cut.

As example no daw should be without Nugens "Mono", it is really a uniquely
helpful image stabilizer if properly used, whatever that is. In principle I
am against making the bass monophonic because some of the ambience
information is in the VLF out of phase stuff, but in the real world so many
people are playing back on mono subwoofer systems that one has to think
compatibility.

> Frank
> Mobile Audio

Kind regards

Peter Larsen

[Gary Eickmeier]

"Scott Dorsey" > wrote in message
...

> Decoded MS and coincident cardioids are mathematically identical and they
> are very close to interchangeable with top-grade microphones. As you get
> to cheaper microphones that are less flat off-axis, the X-Y configuration
> becomes more of an issue since the center of the soundstage is off-axis on
> both mikes.

In other words, coincident XY is the same as MS with the M and S about the
same gain, and also the XY can be converted back to an exactly equivalent MS
pair that can be manipulated just as if the original were MS (?).

Gary

[Peter Larsen[_3_]]

"Gary Eickmeier" > skrev i en meddelelse
...

> "Scott Dorsey" > wrote in message
> ...

>> Decoded MS and coincident cardioids are mathematically identical and they
>> are very close to interchangeable with top-grade microphones. As you get
>> to cheaper microphones that are less flat off-axis, the X-Y configuration
>> becomes more of an issue since the center of the soundstage is off-axis
>> on
>> both mikes.

> In other words, coincident XY is the same as MS with the M and S about the
> same gain, and also the XY can be converted back to an exactly equivalent
> MS pair that can be manipulated just as if the original were MS (?).

LR and MS (sum and difference) are different packaging of the same
information as should be obvious from the simple mathematical operation that
converts one to the other.

> Gary

Kind regards

Peter Larsen

[Scott Dorsey]

Gary Eickmeier > wrote:
>"Scott Dorsey" > wrote in message
...
>
>> Decoded MS and coincident cardioids are mathematically identical and they
>> are very close to interchangeable with top-grade microphones. As you get
>> to cheaper microphones that are less flat off-axis, the X-Y configuration
>> becomes more of an issue since the center of the soundstage is off-axis on
>> both mikes.
>
>In other words, coincident XY is the same as MS with the M and S about the
>same gain, and also the XY can be converted back to an exactly equivalent MS
>pair that can be manipulated just as if the original were MS (?).

Precisely. Assuming perfect microphones, of course.

Now, the downside of this is that with MS and XY and Blumlein you get no
phase imaging, only intensity stereo. This affects low-frequency imaging.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Luxey]

�убота, 31. јануар 2015. 14.07.17 UTC+1, Peter Larsen је напи�ао/ла:
> For deep ensembles, such as those with a concert grand I added an other omni
> on the piano, often but not always only one. Stereo miking of a concert
> grand for spot miking is grossly overevaluated and often causes more stereo
> problems than it solves, I trust the main pair to deliver the stereo image
> and just use the spot mic(s) - suiably delayed - to add focus.

> Kind regards
>
> Peter Larsen

Sorry if I already mentioned this. Some time ago, I've recorded a series of
solo (prepared) piano concerts. However, the deal and the scheduelle was such
taht I'd show there just before the very begining, plug my multitrack into
their PA console and take the signal from inserts. People working there always
did the same set up,
- two cardioid mics (I forgot the model) close to strings and the lid
- Kind of ORTF pair of C1000s' with omni capsules

My job was to record 4 tracks and later mix them for CD (low number run,
self published by artist). Which I did and ok...

Story being, each time I got there, I asked those guys to reverse the setup
for the next concert, put the omnies inside and have cardioids for ORTF,
they'd alwasys say, mmm, cool, we'll do it for the next one and they never
did.

[Tom McCreadie]

"Gary Eickmeier wrote:
>"Scott Dorsey" > wrote in message
...
>
>> Decoded MS and coincident cardioids are mathematically identical and they
>> are very close to interchangeable with top-grade microphones. As you get
>> to cheaper microphones that are less flat off-axis, the X-Y configuration
>> becomes more of an issue since the center of the soundstage is off-axis on
>> both mikes.
>
>In other words, coincident XY is the same as MS with the M and S about the
>same gain, and also the XY can be converted back to an exactly equivalent MS
>pair that can be manipulated just as if the original were MS (?).
>
No, the gain doesn't come into it. You are reversibly and losslessly
"translating" all the stereo information data from its listenable X/Y format
into a not-directly-listenable M/S format (All the information in the MS format
is available to re-create the XY.)

The ratio of M to S that happens to result from the XY -> MS operation will
depend on (a) the polar pattern of the XY mics and (b) their angular splay. And
as a corollary, the pattern and splay of a (virtual) XY pair is driven by the
(a) the chosen M mic polar pattern and (b) the M to S ratio. This "about the
same gain" is irrelevant.

Think of XY <-> MS as a sort of translation process. Take a word "tree";
translate that into French using your an En-Fr dictionary; that may be
unrecognizable for your kids, but once they consult a Fr-En dictionary it all
becomes perfectly clear again.

Many folks have a persistent notion that only MS allows width adjustment (via
gain ratio changes.) Any coincident XY array can do that...just that it's a mite
less convenient, entailing an extra step:
MS -> XY
MS -> ratio change -> M'S' -> X'Y'
XY -> M/S -> ratio change -> M'S' -> X'Y'

[Ron C[_2_]]

On 1/31/2015 8:41 PM, Tom McCreadie wrote:
> "Gary Eickmeier wrote:
>> "Scott Dorsey" > wrote in message
>> ...
>>
>>> Decoded MS and coincident cardioids are mathematically identical and they
>>> are very close to interchangeable with top-grade microphones. As you get
>>> to cheaper microphones that are less flat off-axis, the X-Y configuration
>>> becomes more of an issue since the center of the soundstage is off-axis on
>>> both mikes.
>>
>> In other words, coincident XY is the same as MS with the M and S about the
>> same gain, and also the XY can be converted back to an exactly equivalent MS
>> pair that can be manipulated just as if the original were MS (?).
>>
> No, the gain doesn't come into it. You are reversibly and losslessly
> "translating" all the stereo information data from its listenable X/Y format
> into a not-directly-listenable M/S format (All the information in the MS format
> is available to re-create the XY.)
> < ...big snip... >

Hmm, (on M/S not being directly listenable) I've often wondered
about an M/S speaker setup. Sounds like something that might be
right up Mr. Eickmeier's ally.

Actually, it seems like an ideal technology for TV surround's
left/center/right sound bar in a box type thing.

Hard to imagine this hasn't been experimented with.

==
Later....
Ron Capik
--

[Mike Rivers[_2_]]

On 2/1/2015 3:24 AM, Ron C wrote:
> Hmm, (on M/S not being directly listenable) I've often wondered
> about an M/S speaker setup. Sounds like something that might be
> right up Mr. Eickmeier's ally.

It's been done, and by our old friend Aspen Pittman, formerly of Groove
Tube. He and Drew Daniels developed the concept in the late 1970s.
Fender made a portable PA system half a dozen years ago using an M-S
speaker setup.

http://www.centerpointstereo.com/



--
For a good time, visit http://mikeriversaudio.wordpress.com

[Peter Larsen[_3_]]

"Ron C" > skrev i en meddelelse
...

> Hmm, (on M/S not being directly listenable) I've often wondered
> about an M/S speaker setup. Sounds like something that might be
> right up Mr. Eickmeier's ally.

DR (danish state radio) or one of their enginesearchers built one in the
1950'ties or 1960'ties. Works great. One unit towards to and one behind it
radiating to both sides. Has the interesting property that the closer you
get the wider the image.

> Actually, it seems like an ideal technology for TV surround's
> left/center/right sound bar in a box type thing.

> Hard to imagine this hasn't been experimented with.

And it has. Easy to emulate with a surround center box and behind it a
surround fig8 box. Adding digitat processing to get them coincident comes to
mind ...

> Ron Capik

Kind regards

Peter Larsen

[Gary Eickmeier]

"Tom McCreadie" > wrote in message
...
> "Gary Eickmeier wrote:
>>"Scott Dorsey" > wrote in message
...
>>
>>> Decoded MS and coincident cardioids are mathematically identical and
>>> they
>>> are very close to interchangeable with top-grade microphones. As you
>>> get
>>> to cheaper microphones that are less flat off-axis, the X-Y
>>> configuration
>>> becomes more of an issue since the center of the soundstage is off-axis
>>> on
>>> both mikes.
>>
>>In other words, coincident XY is the same as MS with the M and S about the
>>same gain, and also the XY can be converted back to an exactly equivalent
>>MS
>>pair that can be manipulated just as if the original were MS (?).
>>
> No, the gain doesn't come into it. You are reversibly and losslessly
> "translating" all the stereo information data from its listenable X/Y
> format
> into a not-directly-listenable M/S format (All the information in the MS
> format
> is available to re-create the XY.)
>
> The ratio of M to S that happens to result from the XY -> MS operation
> will
> depend on (a) the polar pattern of the XY mics and (b) their angular
> splay. And
> as a corollary, the pattern and splay of a (virtual) XY pair is driven by
> the
> (a) the chosen M mic polar pattern and (b) the M to S ratio. This "about
> the
> same gain" is irrelevant.
>
> Think of XY <-> MS as a sort of translation process. Take a word "tree";
> translate that into French using your an En-Fr dictionary; that may be
> unrecognizable for your kids, but once they consult a Fr-En dictionary it
> all
> becomes perfectly clear again.
>
> Many folks have a persistent notion that only MS allows width adjustment
> (via
> gain ratio changes.) Any coincident XY array can do that...just that it's
> a mite
> less convenient, entailing an extra step:
> MS -> XY
> MS -> ratio change -> M'S' -> X'Y'
> XY -> M/S -> ratio change -> M'S' -> X'Y'

Well, I am not sure how to word my question, but when you buy an MS recorder
like the Zoom H6 with built-in MS module, you get an adjustment that goes
from Zero dif between M and S in the plus direction all the way to RAW and
in the minus direction (less and less S mike) to zero, or mono. This
suggests that (if there are sounds all around you, not just a solo
instrument up front) that the S = 0 would have both M and S gains equal,
right? Then at that time the MS pair would be exactly equivalent to the XY
Blumlein pair. But with other polar patterns for the M mike than Fig 8, this
equivalency might not hold. Also interesting that coincident stereo is pure
intensity stereo and is subject to this mathematical translation, but does
that hold true for any of the spaced microphone techniques? I mean,
obviously the signal doesn't know how it was obtained, so you could do the
stereo width control on any stereo signal, right?

I guess I should just record my MS in RAW and do as I please with it later,
but I have always wondered how I should ideally be setting my gains while
recording. Should I set both M and S knobs the same and let the signal rise
and fall where it may, or should I set them so that both tracks are equally
loud most of the time? Would that be equivalent to setting the Zoom S signal
to zero difference from M?

Fascinating stuff. And yes, I have and still am reading all about it. I
would normally think that a little spacing between mikes would add something
to the stereo mix (over the coincident techniques), but in practice so far
MS has it hands down in both accuracy and spaciousness.

Gary

[Mike Rivers[_2_]]

On 2/1/2015 11:23 PM, Gary Eickmeier wrote:
> I guess I should just record my MS in RAW and do as I please with it later,
> but I have always wondered how I should ideally be setting my gains while
> recording. Should I set both M and S knobs the same and let the signal rise
> and fall where it may, or should I set them so that both tracks are equally
> loud most of the time?

I don't know the Zoom jargon, but see if there's an option that lets you
record the mid and side signals separately, but monitor the decoded
stereo. That way you can at least hear what you're recording in stereo.

--
For a good time, visit http://mikeriversaudio.wordpress.com

[Peter Larsen[_3_]]

"Gary Eickmeier" > skrev i en meddelelse
...

> I guess I should just record my MS in RAW

That would be the easiest.

> and do as I please with it later,but I have always wondered
> how I should ideally be setting my gains while recording.

So that you do not clip the recording.

> Should I set both M and S knobs the same and let the signal
> rise and fall where it may, or should I set them so that both
> tracks are equally loud most of the time?

You omit a variable: microphone sensitivity. However with matched
microphones you should set the knobs the same and the signal in channels 1
and 2 should be the same or channel 2 (S) a few dB lower. If it is not like
that then your mic stand is likely to be incorrectly positioned or mic
directional patterns incorrectly chosen.

> Would that be equivalent to setting the Zoom S signal to zero difference
> from M?

Doing it.

> Fascinating stuff. And yes, I have and still am reading
> all about it. I would normally think that a little spacing
> between mikes would add something to the stereo mix (over
> the coincident techniques), but in practice so far MS has it hands down in
> both accuracy and spaciousness.

It is always a compromise to record, especially to record live events where
positioning is often "where possible". But nice to hear that a compromise
within solid theory fares better than one well outside it, as your spaced
array most certainly is in the way you use it.

Just never stop learning ... because there is always more to learn :)

> Gary

Kind regards

Peter Larsen

[Gary Eickmeier]

"Peter Larsen" > wrote in message
web.com...

> Just never stop learning ... because there is always more to learn :)
>
> Kind regards
>
> Peter Larsen

Amen. Thanks to all. I think I have everything balanced fairly well now in
the whole throughput from mikes to speakers. I like several miking tehniques
now But MS is holding up as a great "go to" setup for maximum versatility
and minimal intrusion into their show. My playback system seems well suited
to it as well, being surround and semi reflecting. I can walk all around and
the band stays put. I can go closer to them or farther away, just like live.
Walk right up to between the speakers and almost "see" the band and everyone
still where they belong!

Gary

[Fran Guidry]

On Sunday, February 1, 2015 at 10:41:58 PM UTC-8, Peter Larsen wrote:
> "Gary Eickmeier" > skrev i en meddelelse
> ...
....
> > Should I set both M and S knobs the same and let the signal
> > rise and fall where it may, or should I set them so that both
> > tracks are equally loud most of the time?
>
> You omit a variable: microphone sensitivity. However with matched
> microphones you should set the knobs the same and the signal in channels 1
> and 2 should be the same or channel 2 (S) a few dB lower. If it is not like
> that then your mic stand is likely to be incorrectly positioned or mic
> directional patterns incorrectly chosen.
....
>
> Kind regards
>
> Peter Larsen

This certainly doesn't match my experience. If I use matched or similarly sensitive mics and matched gain settings the S signal is _much_ lower than the M signal and if this were not the case I would start looking for my error.

Fran

[Mike Rivers[_2_]]

On 2/2/2015 8:23 PM, Fran Guidry wrote:
> This certainly doesn't match my experience. If I use matched or
> similarly sensitive mics and matched gain settings the S signal
> is_much_ lower than the M signal and if this were not the case I
> would start looking for my error.

Of course that makes sense since they're pointed so that the null is
toward what you're trying to record. However, I usually adjust the
preamp gain so that I get a good level out of the preamp and then adjust
the mid and +/- side mix for the stereo spread that I want.

--
For a good time, visit http://mikeriversaudio.wordpress.com

[Tom McCreadie]

Mike Rivers wrote:

>On 2/2/2015 8:23 PM, Fran Guidry wrote:
>> This certainly doesn't match my experience. If I use matched or
>> similarly sensitive mics and matched gain settings the S signal
>> is_much_ lower than the M signal and if this were not the case I
>> would start looking for my error.
>
>Of course that makes sense since they're pointed so that the null is
>toward what you're trying to record. However, I usually adjust the
>preamp gain so that I get a good level out of the preamp and then adjust
>the mid and +/- side mix for the stereo spread that I want.

Agreed, and sensible advice. A reasonable start is with the applied M and S
channel gains of the preamp/recorder at ca. 1:1 (after due allowance for any
sensitivity differences between M and S mics), then tweak it in real time from
there.

If, instead, you fixated on setting the channel gains purely to ensure that the
recorded signals on the meters flux at equal levels for M and S, you would
almost always be recording with too much S. (Some people do hang on to recording
with M and S both maximized, though, on the dubious rationale that it still
contributes a little to a better S/N ratio or cleaner AD conversion.)

I find it's important to home in fairly close to an optimum M:S ratio in real
time before the concert starts, for only then are you able to properly address
that other important parameter: direct to reverberant ratio.

Image width and direct/reverberant ratio are alas not independent variables - if
you widen the image by increasing the S to M ratio you always get a concomitant
increase in the reverberant to direct ratio. So it pays to strive to nail the
direct/reverberant balance at concert time, by adjusting the stand placement
distance and height.

In post in a DAW, one can always adjust the M to S ratio...but no DAW
post-processing can ever re-adjust the stand position.

[Gary Eickmeier]

"Tom McCreadie" > wrote in message
...
> Mike Rivers wrote:
>
>>On 2/2/2015 8:23 PM, Fran Guidry wrote:
>>> This certainly doesn't match my experience. If I use matched or
>>> similarly sensitive mics and matched gain settings the S signal
>>> is_much_ lower than the M signal and if this were not the case I
>>> would start looking for my error.
>>
>>Of course that makes sense since they're pointed so that the null is
>>toward what you're trying to record. However, I usually adjust the
>>preamp gain so that I get a good level out of the preamp and then adjust
>>the mid and +/- side mix for the stereo spread that I want.
>
> Agreed, and sensible advice. A reasonable start is with the applied M and
> S
> channel gains of the preamp/recorder at ca. 1:1 (after due allowance for
> any
> sensitivity differences between M and S mics), then tweak it in real time
> from
> there.
>
> If, instead, you fixated on setting the channel gains purely to ensure
> that the
> recorded signals on the meters flux at equal levels for M and S, you
> would
> almost always be recording with too much S. (Some people do hang on to
> recording
> with M and S both maximized, though, on the dubious rationale that it
> still
> contributes a little to a better S/N ratio or cleaner AD conversion.)
>
> I find it's important to home in fairly close to an optimum M:S ratio in
> real
> time before the concert starts, for only then are you able to properly
> address
> that other important parameter: direct to reverberant ratio.
>
> Image width and direct/reverberant ratio are alas not independent
> variables - if
> you widen the image by increasing the S to M ratio you always get a
> concomitant
> increase in the reverberant to direct ratio. So it pays to strive to nail
> the
> direct/reverberant balance at concert time, by adjusting the stand
> placement
> distance and height.
>
> In post in a DAW, one can always adjust the M to S ratio...but no DAW
> post-processing can ever re-adjust the stand position.

Are you guys thinking that M will be stronger because it is pointing
straight at the music, whereas S is just doing the sideways ambience? I
smell a rat somewhere in there.

So two questions:

1. What would the M and S gains register on the meters for a source exacty
45° from straight ahead? Equal, right? Admittedly, to this will be added the
straight ahead sources, which will be in the null of the S mike, but then
answer #2:

2. If you were doing Blumlein with two figure 8 mikes, the two channels
would obviously be equal. In this case, a source at 45° would be max in one
channel and in the null of the other. Question 2: What would the
mathematically equivalent MS signals look like? I'm too tired to think right
now, but wouldn't that answer the musical question? Isn't that what the Zoom
H6 is doing with the S set to zero dif from M? That would be knob setting,
not actual levels of course.

Gary

[Peter Larsen[_3_]]

"Gary Eickmeier" > skrev i en meddelelse
...

> Are you guys thinking that M will be stronger because it is pointing
> straight at the music, whereas S is just doing the sideways ambience?

Good stereo has S in the interval -6dB < S < M

> Gary

Kind regards

Peter Larsen

[Tom McCreadie]

Gary Eickmeier wrote:
>
>Are you guys thinking that M will be stronger because it is pointing
>straight at the music, whereas S is just doing the sideways ambience? I
>smell a rat somewhere in there.

In a typical array placement in an auditorium, most of the sound energy will be
direct sound arriving predominantly from the front. The sounds from side and
rear will be predominantly lower level reflected sounds etc. Why do you find
that so surprising?
>
>So two questions:
>
>1. What would the M and S gains register on the meters for a source exacty
>45° from straight ahead? Equal, right? Admittedly, to this will be added the
>straight ahead sources, which will be in the null of the S mike, but then
>answer #2:
>
It depends on the pattern pf the M mic:
_____________________________
45 deg. off-axis M pattern
dB drop
_____________________________
0.00 Omni
0.88 Subcardioid ("V = 0.67 + 0.33.cos.theta")
1.38 Cardioid (Zoom H6 M/S module ?)
1.77 Supercardioid ("V = 0.37 + 0.63.cos.theta")
3.01 fig- 8
______________________________

>2. If you were doing Blumlein with two figure 8 mikes, the two channels
>would obviously be equal. In this case, a source at 45° would be max in one
>channel and in the null of the other. Question 2: What would the
>mathematically equivalent MS signals look like? I'm too tired to think right
>now, but wouldn't that answer the musical question? Isn't that what the Zoom
>H6 is doing with the S set to zero dif from M? That would be knob setting,
>not actual levels of course.

If you take a stereo signal from a conventional +/- 45 deg. Blumlein pair and
perform a standard MS operation on it, the resultant signal - if still played
back as an XY signal - would be what would have come from a Blumlein pair aimed
45 deg left ("North-West") - but with the L and R ouput channels swapped. Clear
as mud? :-)

As for your Zoom H6 M/S module, let's assume firstly that the M mic is a
cardioid pattern and that it has the same sensitivity as its S partner. Then an
M/S with a cardioid for M and at 1:1 M:S gain setting translates mathematically
to a virtual XY array of two supercardioid mics (pattern: V = 0.31 + 0.69
cos.theta), splayed at 127 deg. included angle Such an array would have an SRA
of ca. 85-90 deg.
--
Tom McCreadie

"Ah, where would we be without humour." "Germany?"

[Gary Eickmeier]

"Frank Stearns" > wrote in message
...
> "Gary Eickmeier" > writes:
>
> -snip-
>
>>Additionally, it seems that MS is able to encode direction more accurately
>>and finely than any other miking technique or scheme. I have tried. The
>
> You haven't tried 50 cm A/B with diffraction spheres, then (or perhaps the
> Jeklin
> disk, which I have not tried).
>
> MS has okay L-to-R imaging. But sometimes the LR soundstage "dimension"
> can be
> non-linear the further left or right you go. That is, you can have a
> somewhat
> clustered "centerish" soundstage that then suddenly zips out to far left
> and far
> right. Farther center left and farther center right can kinda be skipped
> over to
> jump directly to that far left and or right. Doesn't happen all the time,
> but it
> can.
>
> Aside from not having a reliably accurate left-to-right, my main complaint
> with MS
> and XY is the lack of true, pin-point, *front-to-back* imaging. That's why
> I largely
> abandoned MS when I heard 50cm A/B. That, and the ability to use omnis
> which,
> because of their much better low end response and more even response in
> general,
> brought on a whole new world of realism, particularly with orchestral
> work.
>
> Frank
> Mobile Audio

My audio engineer friend who does most of the archival gigs in town uses the
50 cm omnis (DAP) and gets fantastic results. What is interesting is that
this would be a purely time of arrival kind of stereo and my MS would be
strictly intensity stereo, and both work well! I had thought that some
combination of the two approaches with some shorter spaced cardioids aimed
right and left would give the best compromise - the best of both - but I was
wrong.

On my MS experiment, I have arrived at a tentative conclusion that the S of
3 dB below M works best for my setup in surround sound. It gives a pretty
much perfect spread of the frontal sound along with strong enough a surround
signal to give the surround feel - actually hearing audience behind me.
Crank it up to realistic levels and whammo, you are THERE.

Gary

[Scott Dorsey]

Gary Eickmeier > wrote:
>
>My audio engineer friend who does most of the archival gigs in town uses the
>50 cm omnis (DAP) and gets fantastic results. What is interesting is that
>this would be a purely time of arrival kind of stereo and my MS would be
>strictly intensity stereo, and both work well! I had thought that some
>combination of the two approaches with some shorter spaced cardioids aimed
>right and left would give the best compromise - the best of both - but I was
>wrong.

If he's using the DPA 4006 omnis, you'll find that they aren't really very
omni. Add the balls onto them and they become even less omni, and that is
what gives you actual intensity stereo.

The M50, as traditionally used in the Decca tree, are even less omni.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Frank Stearns]

(Scott Dorsey) writes:

>Gary Eickmeier > wrote:
>>
>>My audio engineer friend who does most of the archival gigs in town uses the
>>50 cm omnis (DAP) and gets fantastic results. What is interesting is that
>>this would be a purely time of arrival kind of stereo and my MS would be
>>strictly intensity stereo, and both work well! I had thought that some
>>combination of the two approaches with some shorter spaced cardioids aimed
>>right and left would give the best compromise - the best of both - but I was
>>wrong.

>If he's using the DPA 4006 omnis, you'll find that they aren't really very
>omni. Add the balls onto them and they become even less omni, and that is
>what gives you actual intensity stereo.

>The M50, as traditionally used in the Decca tree, are even less omni.

Indeed. The higher frequency directionality adds an intensity component.

And the M50 response is rather peculiar; my understanding is that in part the
Decca tree technique was birthed to work around that odd response.

Once again, KM183s (or 183Ds) using 50 cm spacing, 120 degree splay, 20 degree
up-tilt, with the balls, is the most accurate imaging I've ever heard.

But, I'll still put a 17 cm ORTF pair on the same stick. This is handy to deal with
any room oddities, or to "reach in" if a little presence is needed. Because the
stick location is optimized for the omnis, the ORTF is actually "too close" and
would not be pleasant all by itself. But mixed in underneath it can lend a helping
hand when the 50 cm omnis reveal all too well problems with the room or the
players. ;)

Frank
Mobile Audio
--

[Scott Dorsey]

Frank Stearns > wrote:
(Scott Dorsey) writes:
>
>>The M50, as traditionally used in the Decca tree, are even less omni.
>
>Indeed. The higher frequency directionality adds an intensity component.
>
>And the M50 response is rather peculiar; my understanding is that in part the
>Decca tree technique was birthed to work around that odd response.

Yes, I have tried, and seen others try, to make the Decca tree work with
other microphones and never been satisfied with the results. It does seem
very dependent on the weird beaming of the M50.

>Once again, KM183s (or 183Ds) using 50 cm spacing, 120 degree splay, 20 degree
>up-tilt, with the balls, is the most accurate imaging I've ever heard.

Try the Jecklin!
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[John Williamson]

On 10/02/2015 14:42, Scott Dorsey wrote:
> Frank Stearns > wrote:
>> (Scott Dorsey) writes:
>>
>>> The M50, as traditionally used in the Decca tree, are even less omni.
>>
>> Indeed. The higher frequency directionality adds an intensity component.
>>
>> And the M50 response is rather peculiar; my understanding is that in part the
>> Decca tree technique was birthed to work around that odd response.
>
> Yes, I have tried, and seen others try, to make the Decca tree work with
> other microphones and never been satisfied with the results. It does seem
> very dependent on the weird beaming of the M50.
>
I've had good results using a pair of Marshal MXL603's and an MXL604,
which surprised me somewhat, as they're not by any stretch of the
imagination omni.


--
Tciao for Now!

John.

[Gary Eickmeier]

All -


I am trying the Soundcloud program for aharing music files. Not as good as
sending you a CD, but one way to show and tell about a recording session
without the trouble of mailing.

So here is the setup. These guys are some of them snowbirds from up north,
some retirees from here. Anywayh, this is the breakoff dance band group from
the big wind band the Lakeland Concert Band. They just have fun trying to be
good enough to play for a dance with paying customers. And the old timers in
the trailer parks are delighted to kick up their heels.

And me to record them. OK, so the music is not GREAT, but I can still try
for maximum realism in the sound and polish my recording techniques. Again,
this one with MS from the AT 2050 multi pattern mikes in Fig 8 mode I was 10
ft from the front line of saxes, and the group was 24 ft wide and 14 ft
deep.

http://g4.img-dpreview.com/044FD48509DF45F88BAE1C091C9EE57C.jpg

http://g1.img-dpreview.com/9B5A5AD1E3F84C49B2A126090824AECC.jpg

https://soundcloud.com/eickmeier-1/what-kind-of-fool-3wav

Gary

[Luxey]

I loved the phone ringing. Maybe if you'd turn the whole mic set some 60 degrees clockwise?

[JackA]

On Thursday, February 12, 2015 at 1:30:44 PM UTC-5, Gary Eickmeier wrote:
> All -
>
>
> I am trying the Soundcloud program for aharing music files. Not as good as
> sending you a CD, but one way to show and tell about a recording session
> without the trouble of mailing.
>
> So here is the setup. These guys are some of them snowbirds from up north,
> some retirees from here. Anywayh, this is the breakoff dance band group from
> the big wind band the Lakeland Concert Band. They just have fun trying to be
> good enough to play for a dance with paying customers. And the old timers in
> the trailer parks are delighted to kick up their heels.
>
> And me to record them. OK, so the music is not GREAT, but I can still try
> for maximum realism in the sound and polish my recording techniques. Again,
> this one with MS from the AT 2050 multi pattern mikes in Fig 8 mode I was 10
> ft from the front line of saxes, and the group was 24 ft wide and 14 ft
> deep.
>
> http://g4.img-dpreview.com/044FD48509DF45F88BAE1C091C9EE57C.jpg
>
> http://g1.img-dpreview.com/9B5A5AD1E3F84C49B2A126090824AECC.jpg
>
> https://soundcloud.com/eickmeier-1/what-kind-of-fool-3wav
>
> Gary

Gary, not bad [love the studio talk!], but it sounds like an old recording. GENERALLY I think that was due to the lack of an electric bass guitar. Rather rearrange (group) the horns, you know sax on left, trumpets center, maybe trombones at right, use several mics, one for each group, then mix. But what do I know!?
Maybe some swing would perk my ears up! I love horns, and big bands!!

Footnote, even though I "LOVE" stereo, it's hard for me to really like a lot of Sinatra recordings [example]. First, you hear the band on the right (intro), then Frank (vocals) in the center, then finally the strings on the left. Many songs were recorded like that.

I didn't mind the clams! :-)

[JackA]

On Thursday, February 12, 2015 at 2:08:14 PM UTC-5, Luxey wrote:
> I loved the phone ringing. Maybe if you'd turn the whole mic set some 60 degrees clockwise?

Luxey...

From the 1941(?) Glenn Miller film! Someone found the film audio had two tracks. Someone, I guess, simulated the stereo of the band, but you can definitely hear the vocals are separated!! I GUESS this was done to balance singing and music in monophonic! Just so neat to hear!!!...

http://www.angelfire.com/empire/abpsp/images/choochoo-s2.mp3

Jack

[Frank Stearns]

"Gary Eickmeier" > writes:

>All -

>And me to record them. OK, so the music is not GREAT, but I can still try
>for maximum realism in the sound and polish my recording techniques. Again,
>this one with MS from the AT 2050 multi pattern mikes in Fig 8 mode I was 10
>ft from the front line of saxes, and the group was 24 ft wide and 14 ft
>deep.

>https://soundcloud.com/eickmeier-1/what-kind-of-fool-3wav

Seems like the biggest sonic problem is the drop ceiling -- early (and uneven)
reflections in the higher mid and top, then more oddities as the mids and bass
reflect off the harder, denser surface that's a few feet above the drops.

This leads to some odd image hot spots, along with some peculiar phasiness. Might be
nothing wrong with the technique but I'd not want to judge it one way or another
until it was possible to record in a more acoustically friendly room.

Stay at it.

Frank
Mobile Audio

--

[Gary Eickmeier]

"Frank Stearns" > wrote in message
...

> Seems like the biggest sonic problem is the drop ceiling -- early (and
> uneven)
> reflections in the higher mid and top, then more oddities as the mids and
> bass
> reflect off the harder, denser surface that's a few feet above the drops.
>
> This leads to some odd image hot spots, along with some peculiar
> phasiness. Might be
> nothing wrong with the technique but I'd not want to judge it one way or
> another
> until it was possible to record in a more acoustically friendly room.
>
> Stay at it.
>
> Frank
> Mobile Audio

Interesting comments all. This is just a rehearsal of course, but they
usually arrange themselves the same way in most performances. I have no say
in that. The rooms would be a lot larger at the performances.

I nailed the problem of the heavy bass tonight. Heard it again during
tonight's rehearsal. Things were going along fine until suddenly there was
this excess hum from the electric bass speaker. Then during that song I
heard the dreaded Thum thum thum of the bass overwhelming everything and
everybody. I had to speak up and have him turn it down because it was
ruining every song. Later, the guitarist confided that he wore two hearing
aids and had his speaker positioned behind him so he couldn't hear much of
anything out of it and turned it up all the way.

I wonder why the leader didn't hear it and look for the problem and get a
better balance.

Gary

[Luxey]

On Friday, 13 February 2015 11:58:09 UTC+1, Gary Eickmeier wrote:

> I wonder why the leader didn't hear it and look for the problem and get a
> better balance.
>
> Gary

Because he's not that f*ck'n' awesome, like you are, my dear Gary.

[Gary Eickmeier]

"Luxey" > wrote in message
...
> On Friday, 13 February 2015 11:58:09 UTC+1, Gary Eickmeier wrote:
>
>> I wonder why the leader didn't hear it and look for the problem and get a
>> better balance.
>>
>> Gary
>
> Because he's not that f*ck'n' awesome, like you are, my dear Gary.
>
He is a volunteer and has other problems to deal with than recording quality
sound.

Gary

[Gary Eickmeier]

A possible new problem has come up with MS, namely some imaging anomalies at
different frequencies. When I do my stereo test and even during a
performance, I have noticed that higher frequency percussive sounds will
image in the center more than at left or right. Like, the drum set is at
stage left, but there are some pings and other sounds that come from the
center.

Is this some well known principle, or fault, of MS? Ever heard of it?

Gary

[Peter Larsen[_3_]]

"Gary Eickmeier" > skrev i en meddelelse
...

> A possible new problem has come up with MS, namely some imaging
> anomalies at different frequencies.

Yes and no, ie. I trust them to be there and they are not a result of MS, MS
and XY remains mathematically equivalent. There is then the issue of stereo
acceptance angle, ie. the room segment that is placed between L and R, see
also the paper "The Stereophonic Zoom".

> When I do my stereo test and even during a performance, I have noticed
> that higher frequency percussive sounds will image in the center more than
> at left or right. Like, the drum set is at stage left, but there are some
> pings and other sounds that come from the center.

> Is this some well known principle, or fault, of MS? Ever heard of it?

You are using large membrane microphones AND you tell us you evaluate stereo
played back as 5.1. All bets are off for both reasons, the most likely cause
is however large membrane anomalies.

To evaluate mic off axis behaviour:

set up recorder to record one channel

connect one microphone to recorder

set recorder to record

hold microphone in a straight arm in front of you

be on axis

recite Mary had a little lamb, entire poem

rotate microphone so that you are 45 degrees off axis

recite Mary had a little lamb, entire poem

rotate microphone so that you are 90 degrees off axis

recite Mary had a little lamb, entire poem

rotate microphone so that you are 135 degrees off axis

recite Mary had a little lamb, entire poem

rotate microphone so that you are 180 degrees off axis

recite Mary had a little lamb, entire poem

Listen to recording and evaluate, fft analysis may or may not be
informative.

If you are really bored repeat with the other three microphones, they will
probably be somewhat different.

The expected difference is that any treble "issues" will be more prominent
off axis if correlated with resonance in the housing, but you'll be the
first to know. Consider one microphone aimed at the drumkit and linear on
axis and one microphone aimed 90 degrees away from the drumkit BUT "almost
omni"" from 7200 to 8800 Hz because of a resonance and it gets obvious why
the intensity information will cause the highhat to move towards center.

Speak at one meter, even if only on axis, is a very good fast way to compare
microphones and select the best sounding. It was such a test that made me
skip buying calrec condensers in the early 1980'ties, however I also didn't
really have very much use for them then, if I had really needed them I had
asked for some more to compare and selected the two best.

> Gary

Kind regards

Peter Larsen

[Frank Stearns]

"Gary Eickmeier" > writes:

>A possible new problem has come up with MS, namely some imaging anomalies at
>different frequencies. When I do my stereo test and even during a
>performance, I have noticed that higher frequency percussive sounds will
>image in the center more than at left or right. Like, the drum set is at
>stage left, but there are some pings and other sounds that come from the
>center.

>Is this some well known principle, or fault, of MS? Ever heard of it?

Of course, it's called lousy microphone response.

Stop and consider for a moment running your side level up and down, and what that
does to stereo width. Then think about 10, 15, 20 dB variances of response in your
micropphones at various frequencies. It's like running the side level up and down --
at those frequencies.

Your off-axis response of the side mic probably isn't very good, and/or there's a
serious level mismatch between the M and S microphones at various frequencies.

Just one more reason why I appreciate a technique where I can use good omnis. :)

Frank
Mobile Audio
--

[Scott Dorsey]

Gary Eickmeier > wrote:
>A possible new problem has come up with MS, namely some imaging anomalies at
>different frequencies. When I do my stereo test and even during a
>performance, I have noticed that higher frequency percussive sounds will
>image in the center more than at left or right. Like, the drum set is at
>stage left, but there are some pings and other sounds that come from the
>center.
>
>Is this some well known principle, or fault, of MS? Ever heard of it?

It's a room problem. Move the mike.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[John Williamson]

On 14/02/2015 18:09, Gary Eickmeier wrote:
> "Scott Dorsey" > wrote in message
> ...
>> Gary Eickmeier > wrote:
>>> A possible new problem has come up with MS, namely some imaging anomalies
>>> at
>>> different frequencies. When I do my stereo test and even during a
>>> performance, I have noticed that higher frequency percussive sounds will
>>> image in the center more than at left or right. Like, the drum set is at
>>> stage left, but there are some pings and other sounds that come from the
>>> center.
>>>
>>> Is this some well known principle, or fault, of MS? Ever heard of it?
>>
>> It's a room problem. Move the mike.
>> --scott
>
> Great responses - thanks to all. I will try some of the tests you suggest.
> Could well be a mike problem, changing the M to S ratio with frequency.
> Don't know what the test results might be, but all I can tell you is that I
> am using the Audio Technica 2050 variable pattern mikes in Fig 8 pattern.
> These are reasonable quality for a beginner like me and I would expect that
> would work reasonably well, and maybe my MS mix isn't quite perfiect yet.
> And BTW the same phenomenon holds true looking at the lissajous pattern, or
> phase response window in Audition, so it is a recording problem and not so
> much playback - but I do realize how the rear speakers can affect perceived
> frontal direction as well so I will do more testing in stereo only.
>
>
You could try altering the EQ on the S channel to alter the relative
levels of the HF percussion. If it moves in and out, you've got a
frequency response problem. Then you need to find out how much is the
room and how much is the microphones.


--
Tciao for Now!

John.

[Gary Eickmeier]

"John Williamson" > wrote in message
...

> You could try altering the EQ on the S channel to alter the relative
> levels of the HF percussion. If it moves in and out, you've got a
> frequency response problem. Then you need to find out how much is the room
> and how much is the microphones.
>
>
> --
> Tciao for Now!
>
> John.

Actually, Scott is probably the most correct because it is a fairly tubby
room (almost echoey). So what I should do is a new series of tests outdoors
when it is quiet outside. I can easily do MS and then XY and see just where
the problem lies, in the mikes or in the room.

Gary

[hank alrich]

Gary Eickmeier > wrote:

> I
> am using the Audio Technica 2050 variable pattern mikes in Fig 8 pattern.
> These are reasonable quality for a beginner like me and I would expect that
> would work reasonably well, and maybe my MS mix isn't quite perfiect yet.

Off-axis response is important for your purposes, and smooth off-axis
response is often difficult to find, even more so with inexpensive
LDC's.

--
shut up and play your guitar * HankAlrich.Com
HankandShaidriMusic.Com
YouTube.Com/WalkinayMusic

[Tom McCreadie]

John Williamson wrote:

>You could try altering the EQ on the S channel to alter the relative
>levels of the HF percussion. If it moves in and out, you've got a
>frequency response problem.
But altering the HF equalization on the S channel - or the M channel, for that
matter - will _always_ make the imaging of HF components move in or out. That's
pure physics, and such a phenomenon would also occur with perfect mics, so one
can't use such an experimental outcome to draw a conclusion on Gary's case.

His AT mics may well have an uneven off-axis response, but he was employing two
fig8 mics, so if the AT manufacturing process results mainly in a systematic-
rather than random frequency response skew in the mic patterns, there may be a
fortuitous "close-tolerance unevenness-matching" :-) between M and S mics, that
would provide a mitigating effect.

An ideal Fig8 MS with -3dB S gain equates mathematically to a Fig8 XY pair
splayed at ±35.3°. That would have a Sengpiel SRA of ±47.7° (with the
ambiophonic region beginning beyond ±54.7°). The front desks subtended an angle
of ±50.2° to the mic array, and the drummer lay within that angle. So it seems
unlikely that the drummer's wide positioning contributed to the perceived weird
imaging.

I can't listen with any Dolby surround set-up, but I'd first suspect the dismal
room geometry and reflections as the main culprit for any imaging anomalies
(Fig8's might actually have helped here against that the low ceiling?) Actually,
I didn't find the image shifting very distracting...and thought Gary did a
pretty credible job, considering the tools he had and the hall he had to contend
with.

But wow, those heavy mics supported by that lone, dinky stand-base
thread!...that does make me shiver. Also, those Fig8 mics may be vulnerable to
stand-borne resonances. And perhaps consider relocating the bass amp, not the
player, to a more central position?

[Scott Dorsey]

Gary Eickmeier > wrote:
>"Scott Dorsey" > wrote in message
...
>> Gary Eickmeier > wrote:
>>>A possible new problem has come up with MS, namely some imaging anomalies
>>>at
>>>different frequencies. When I do my stereo test and even during a
>>>performance, I have noticed that higher frequency percussive sounds will
>>>image in the center more than at left or right. Like, the drum set is at
>>>stage left, but there are some pings and other sounds that come from the
>>>center.
>>>
>>>Is this some well known principle, or fault, of MS? Ever heard of it?
>>
>> It's a room problem. Move the mike.
>
>Great responses - thanks to all. I will try some of the tests you suggest.
>Could well be a mike problem, changing the M to S ratio with frequency.

You're using two identical mikes, so the response should be the same,
right? It's true that if the side mike has poor high frequency response
off-axis, or is just soft on top, that high frequency things will collapse
into the center of the soundfield. I experienced this with a 77DX
combined with an omni condenser, back when I was a student.

But I'm inclined to think you have reflection issues in your room.

>Don't know what the test results might be, but all I can tell you is that I
>am using the Audio Technica 2050 variable pattern mikes in Fig 8 pattern.
>These are reasonable quality for a beginner like me and I would expect that
>would work reasonably well, and maybe my MS mix isn't quite perfiect yet.
>And BTW the same phenomenon holds true looking at the lissajous pattern, or
>phase response window in Audition, so it is a recording problem and not so
>much playback - but I do realize how the rear speakers can affect perceived
>frontal direction as well so I will do more testing in stereo only.

Measure it and see. Set up the mike outside, start recording, then walk
a circle around the microphone jingling a set of keys and calling out where
you are. If the high frequency response varies with position, you'll be
able to tell it from just a drop in amplitude overall.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Gary Eickmeier]

"Tom McCreadie" > wrote in message
...
> John Williamson wrote:
>
>>You could try altering the EQ on the S channel to alter the relative
>>levels of the HF percussion. If it moves in and out, you've got a
>>frequency response problem.
> But altering the HF equalization on the S channel - or the M channel, for
> that
> matter - will _always_ make the imaging of HF components move in or out.
> That's
> pure physics, and such a phenomenon would also occur with perfect mics, so
> one
> can't use such an experimental outcome to draw a conclusion on Gary's
> case.
>
> His AT mics may well have an uneven off-axis response, but he was
> employing two
> fig8 mics, so if the AT manufacturing process results mainly in a
> systematic-
> rather than random frequency response skew in the mic patterns, there may
> be a
> fortuitous "close-tolerance unevenness-matching" :-) between M and S
> mics, that
> would provide a mitigating effect.

The drummer was actually pretty close to halfway between the M and S
patterns, so if it was off axis it was probably the same for both. But on
the stereo call out test I first noticed this, my voice would go where it
belonged but the clicks on my rosewood sticks would go toward the center
more.
>
> An ideal Fig8 MS with -3dB S gain equates mathematically to a Fig8 XY pair
> splayed at ±35.3°. That would have a Sengpiel SRA of ±47.7° (with the
> ambiophonic region beginning beyond ±54.7°). The front desks subtended an
> angle
> of ±50.2° to the mic array, and the drummer lay within that angle. So it
> seems
> unlikely that the drummer's wide positioning contributed to the perceived
> weird
> imaging.
>

This agrees pretty much with what I am hearing in playback. The extreme
channel material is in the Dolby zone kind of beyond the left or right
walls. I am now using S as 6 dB down for that reason. This varies with each
session I suppose, depending on how perfectly I balance the channels during
recording. The indicated knob position is not accurate. I just balance the
channels on recording, then take care of the M to S ratio during post.

> I can't listen with any Dolby surround set-up, but I'd first suspect the
> dismal
> room geometry and reflections as the main culprit for any imaging
> anomalies
> (Fig8's might actually have helped here against that the low ceiling?)
> Actually,
> I didn't find the image shifting very distracting...and thought Gary did a
> pretty credible job, considering the tools he had and the hall he had to
> contend
> with.
>
> But wow, those heavy mics supported by that lone, dinky stand-base
> thread!...that does make me shiver. Also, those Fig8 mics may be
> vulnerable to
> stand-borne resonances. And perhaps consider relocating the bass amp, not
> the
> player, to a more central position?

Oh, believe me, some additional training will be required for him. He can't
hear his levels very well, so between tracks he turns it down, and for each
track he turns it all the way up again. I am going to have to try some
stealth training to get him to put a mark on the knob and set it by eye to a
reasonable level.

On the mike stand, you may be right. Here is a better shot of the MS
bracket:

https://s3.amazonaws.com/masters.galleries.dpreview.com/3142703.jpg?X-Amz-Expires=3600&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWXD4UV3FXMIDQLQ/20150215/us-east-1/s3/aws4_request&X-Amz-Date=20150215T041902Z&X-Amz-SignedHeaders=host&X-Amz-Signature=188f08a402993f4eabeec245fd6e185f40bbe8e7 cffa2c34e8cac6a5ae4547c4

https://s3.amazonaws.com/masters.galleries.dpreview.com/3142702.jpg?X-Amz-Expires=3600&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWXD4UV3FXMIDQLQ/20150215/us-east-1/s3/aws4_request&X-Amz-Date=20150215T042024Z&X-Amz-SignedHeaders=host&X-Amz-Signature=95c6b05fe4ad6c88888599e7c891e98138050927 7da1e3416c0bd5296857c590

I know, I know, TinyURL but I haven't got time to mess with it.

I have been looking for a one piece MS microphone but not impressed with the
reviews on them or the prices. Maybe e-bay could help.

Gary


>

[Gary Eickmeier]

I'm not sure you can hear what I am talking about in a soundcloud file, but
what the hell:

https://soundcloud.com/eickmeier-1/stereo-test-4wav

https://soundcloud.com/eickmeier-1/stompin-at-the-savoy-4wav

Gary

[Luxey]

недеља, 15. фебруар 2015. 07.18.11 UTC+1, Gary Eickmeier је напи�ао/ла:
> This agrees pretty much with what I am hearing in playback. The extreme
> channel material is in the Dolby zone kind of beyond the left or right
> walls. I am now using S as 6 dB down ...

Well, turn it up!

Also, for a check, stick your head where the mic setup is and haave someone els hit the sticks arround. What do you hear?

Again, with setup as is, and levels as they are, I suggest turning whole setup 60 degrees clockwise.

[Gary Eickmeier]

Luxey wrote:
> ??????, 15. ??????? 2015. 07.18.11 UTC+1, Gary Eickmeier ??
> ???????/??:
>> This agrees pretty much with what I am hearing in playback. The
>> extreme channel material is in the Dolby zone kind of beyond the
>> left or right walls. I am now using S as 6 dB down ...
>
> Well, turn it up!
>
> Also, for a check, stick your head where the mic setup is and haave
> someone els hit the sticks arround. What do you hear?
>
> Again, with setup as is, and levels as they are, I suggest turning
> whole setup 60 degrees clockwise.

You keep saying that - what's up with that?

I have done a few experiments outdoors - will report later when it isn't so
late.

Gary

[Tom McCreadie]

Gary Eickmeier wrote:
>
>"Tom McCreadie" > wrote in message
...

>> But wow, those heavy mics supported by that lone, dinky stand-base
>> thread!...that does make me shiver. Also, those Fig8 mics may be
>> vulnerable to stand-borne resonances.
>
>On the mike stand, you may be right. Here is a better shot of the MS
>bracket:
>
>https://s3.amazonaws.com/masters.galleries.dpreview.com/3142703.jpg?X-Amz-Expires=3600&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWXD4UV3FXMIDQLQ/20150215/us-east-1/s3/aws4_request&X-Amz-Date=20150215T041902Z&X-Amz-SignedHeaders=host&X-Amz-Signature=188f08a402993f4eabeec245fd6e185f40bbe8e7 cffa2c34e8cac6a5ae4547c4
>
>https://s3.amazonaws.com/masters.galleries.dpreview.com/3142702.jpg?X-Amz-Expires=3600&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWXD4UV3FXMIDQLQ/20150215/us-east-1/s3/aws4_request&X-Amz-Date=20150215T042024Z&X-Amz-SignedHeaders=host&X-Amz-Signature=95c6b05fe4ad6c88888599e7c891e98138050927 7da1e3416c0bd5296857c590
>
>I know, I know, TinyURL but I haven't got time to mess with it.

Those two links gave me an "Access denied... Message has expired"

To clarify, though, my comment wasn't on the mic holder arrangement, but rather
about the central pole (with its heavy attachments) only being connected to the
stand base by means of a single, flimsy screw thread. I'd be nervous about the
stand swaying, resonating, capsizing or snapping off.
--
Tom McCreadie

[Luxey]

понедељак, 16. фебруар 2015. 09.07.06 UTC+1, Gary Eickmeier је напи�ао/ла:
> You keep saying that - what's up with that?

Almost everyone told you to move the microphones, I also said so, in a form of
which way to do so.

> I have done a few experiments outdoors - will report later when it isn't so
> late.

What's the point of eperimenting outside? To her the setup without reflections?
Thaat may give you an idea, or a clue, but the point is, you can not set and
forget yor microphones based on some idea, you have to listen and adapt as per
given space and situation.

[Gary Eickmeier]

"hank alrich" > wrote in message
...
> Luxey > wrote:
>
>> ?????????, 16. ??????? 2015. 09.07.06 UTC+1, Gary Eickmeier ??
>> ???????/??:
>> > You keep saying that - what's up with that?
>>
>> Almost everyone told you to move the microphones, I also said so, in a
>> form of
>> which way to do so.
>>
>> > I have done a few experiments outdoors - will report later when it
>> > isn't so
>> > late.
>>
>> What's the point of eperimenting outside? To her the setup without
>> reflections? Thaat may give you an idea, or a clue, but the point is, you
>> can not set and forget yor microphones based on some idea, you have to
>> listen and adapt as per given space and situation.
>
> This is a critical point. Monitoring.

"Move the microphones" - I set up my microphones to record single point
stereo with the perspective that I want to hear on the recording. You don't
move them to a bad perspective for some sonic problem. I would think you
solve the problem. Of course if it were a recording session, you could move
the entire band to someplace that didn't have the problem, but Lux is
telling me to turn the mikes 60 degrees to the right and have the
perspective of a band in the left channel and nothing in the right. I don't
know if he is punking me or what.

Monitoring - yes, sure, you never shoot or record without monitoring the
sound, but I am recording in MS RAW, which is not real helpful for telling
how the stereo is going.

And there are some real surprising - even humorous - anomolies happening
with a pair of Fig 8 mikes after decoding to stereo that I will show and
tell about when I get time to post my results of testing outdoors.

Gary

[Gary Eickmeier]

"Tom McCreadie" > wrote in message
...
> Gary Eickmeier wrote:

>>I know, I know, TinyURL but I haven't got time to mess with it.
>
> Those two links gave me an "Access denied... Message has expired"
>
> To clarify, though, my comment wasn't on the mic holder arrangement, but
> rather
> about the central pole (with its heavy attachments) only being connected
> to the
> stand base by means of a single, flimsy screw thread. I'd be nervous
> about the
> stand swaying, resonating, capsizing or snapping off.
> --
> Tom McCreadie

Hmmm - I thought I tested those links after I sent them. Sorry about that.

This is not my main mike stand, just easier to carry and put up since my
back surgery. Seems to be plenty sturdy.

Gary

[Scott Dorsey]

Gary Eickmeier > wrote:
>
>"Move the microphones" - I set up my microphones to record single point
>stereo with the perspective that I want to hear on the recording. You don't
>move them to a bad perspective for some sonic problem.

There are lots of places with a good perspective. One of them might be
six inches away from where you are now. Stick your finger in your ear,
listen with one ear, move your head around and see.

When you come across a standing wave problem at high frequencies or a
flutter echo, you'll hear it very easily with one ear and you might not
notice it so easily with both.

>I would think you
>solve the problem. Of course if it were a recording session, you could move
>the entire band to someplace that didn't have the problem, but Lux is
>telling me to turn the mikes 60 degrees to the right and have the
>perspective of a band in the left channel and nothing in the right. I don't
>know if he is punking me or what.

No, that's not what he's telling you, I don't believe.

>Monitoring - yes, sure, you never shoot or record without monitoring the
>sound, but I am recording in MS RAW, which is not real helpful for telling
>how the stereo is going.

So, basically you have no real monitoring in the field, which is really
much of your problem. It's possible to work this way but it's a whole lot
more difficult and you have to leave a lot to chance.

>And there are some real surprising - even humorous - anomolies happening
>with a pair of Fig 8 mikes after decoding to stereo that I will show and
>tell about when I get time to post my results of testing outdoors.

My suspicion is that what you're encountering are normal room problems.
It goes with the territory.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Luxey]

понедељак, 16. фебруар 2015. 21.53.33 UTC+1, Gary Eickmeier је напи�ао/ла:
is a critical point. Monitoring.
>
> "Move the microphones" - I set up my microphones to record single point
> stereo with the perspective that I want to hear on the recording.

Pardone moi, but I thought you did not like what you heard on that recording, just like I did not. If you liked it and that is what you were after, then why are we even talking about it? Listen aand enjoy!

[Gary Eickmeier]

"Scott Dorsey" > wrote in message
...

> Measure it and see. Set up the mike outside, start recording, then walk
> a circle around the microphone jingling a set of keys and calling out
> where
> you are. If the high frequency response varies with position, you'll be
> able to tell it from just a drop in amplitude overall.
> --scott

I took the stereo pair outside and did it in stereo in several mike patterns
but now I see you are saying to do it with just one mike and check the roll
off. But I am afraid my keys are not jingly enough to I got my sticks out
again for click tests all around.

Stay tuned, maybe on a new thread. I am getting less and less fascinated
with MS.

Gary

[Frank Stearns]

"Gary Eickmeier" > writes:


snips

>The problem I have discovered is from the miking technique (MS) rather than
>the mikes or moving the mikes or my perspective. I will demonstrate as soon
>as I can upload some files, but the idea is the Fig 8 pattern that I have
>been using has a channel reversal in the rear and some strange left channel
>problems that are probably associated with that and the decoding process.

Yes, there are limits to MS, as I've noted before. What do you think you've
discovered?

BTW, forgot to mention earlier as a possible source of irritation when doing MS: By
no means are all figure 8 microphones created equally. Polar response -- and even
the actual output volume -- might be different between the front and rear lobes of
the same fig 8 mic! (In fact, with some of the Royer ribbons, the company warns
about a different output level between front and rear.)

Thus, it's bad enough when the response between the M and S microphones are off
(either due to different mic types or due to poor off-axis response of the S mic
even if the same model as M), but then you discover issues with an asymmetrical
response between S+ and S-!

Ouch.

About the only way I'd go back to MS would be with the Schoeps or Neumann MS rigs --
both (IRCC) well north of US$5000 by the time you got done. I can get a better sound
for well less than half that investment using omnis.

Interestingly, the advanced (or maybe it was a 3rd party custom) Schoeps MS rig at
one time included a third mic -- an omni -- to compensate for the overall
less-than-adequate LF response of the directional microphones used for the main M-S.
They even included some sort of crossover network to blend the LF omni with the mid,
if I remember correctly. That rig was very expensive.)

Frank
Mobile Audio

--

[None]

"Gary Eickmeier" > wrote in message
...
> ... the Fig 8 pattern that I have been using has a channel reversal
> in the rear and some strange left channel problems that are probably
> associated with that and the decoding process.

LOL! Your figure eight microphone has "channel reversal in the rear."
An astounding discovery! Did you expect otherwise?

[hank alrich]

Frank Stearns > wrote:

> About the only way I'd go back to MS would be with the Schoeps or Neumann
> MS rigs -- both (IRCC) well north of US$5000 by the time you got done. I
> can get a better sound for well less than half that investment using
> omnis.

Josephson C700S.

--
shut up and play your guitar * HankAlrich.Com
HankandShaidriMusic.Com
YouTube.Com/WalkinayMusic

[hank alrich]

Gary Eickmeier > wrote:

> "Scott Dorsey" > wrote in message
> ...
>
> > Measure it and see. Set up the mike outside, start recording, then walk
> > a circle around the microphone jingling a set of keys and calling out
> > where
> > you are. If the high frequency response varies with position, you'll be
> > able to tell it from just a drop in amplitude overall.
> > --scott
>
> I took the stereo pair outside and did it in stereo in several mike patterns
> but now I see you are saying to do it with just one mike and check the roll
> off. But I am afraid my keys are not jingly enough to I got my sticks out
> again for click tests all around.
>
> Stay tuned, maybe on a new thread. I am getting less and less fascinated
> with MS.
>
> Gary

Gary, the combo of your inexpesnive kit, your lack of understanding, and
your "monitoring" makes for quite a sonic party. Your opinions of what
is what will not hold past a certain point, because frankly in some
areas they border on delusional. Please step back from them and at least
_try_ to get your head around many things that have been told you here.

MS works terrificly well when well implemented. Imagine that. Accept
that. Then stop blaming the mic configuration and start listening. If
you give Scott that same rig in the same room with the same sources you
will be startled at the result. In fact, hiring him to come consult on
even a single recording might be a wise approach to this, as so much of
what is needed is education.

--
shut up and play your guitar * HankAlrich.Com
HankandShaidriMusic.Com
YouTube.Com/WalkinayMusic

[Frank Stearns]

(hank alrich) writes:

>Frank Stearns > wrote:

>> About the only way I'd go back to MS would be with the Schoeps or Neumann
>> MS rigs -- both (IRCC) well north of US$5000 by the time you got done. I
>> can get a better sound for well less than half that investment using
>> omnis.

>Josephson C700S.

Nice. Spendy. Nice and Spendy. :) But, knowing Mr. Josephson, worth every penny.

Frank

--

[Scott Dorsey]

Frank Stearns > wrote:
(hank alrich) writes:
>
>>Frank Stearns > wrote:
>
>>> About the only way I'd go back to MS would be with the Schoeps or Neumann
>>> MS rigs -- both (IRCC) well north of US$5000 by the time you got done. I
>>> can get a better sound for well less than half that investment using
>>> omnis.
>
>>Josephson C700S.
>
>Nice. Spendy. Nice and Spendy. :) But, knowing Mr. Josephson, worth every penny.

I don't know. If I had that kind of money, I think I'd sooner go with a
pair of Josephson C617 omnis, assuming I had good rooms to work with. But
then again, you don't always have good rooms to work with. And sometimes
you have a customer who is obsessed with mono compatibility.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[hank alrich]

Scott Dorsey > wrote:

> Frank Stearns > wrote:
> (hank alrich) writes:
> >
> >>Frank Stearns > wrote:
> >
> >>> About the only way I'd go back to MS would be with the Schoeps or Neumann
> >>> MS rigs -- both (IRCC) well north of US$5000 by the time you got done. I
> >>> can get a better sound for well less than half that investment using
> >>> omnis.
> >
> >>Josephson C700S.
> >
> >Nice. Spendy. Nice and Spendy. :) But, knowing Mr. Josephson, worth
> >every penny.
> >
>
> I don't know. If I had that kind of money, I think I'd sooner go with a
> pair of Josephson C617 omnis, assuming I had good rooms to work with. But
> then again, you don't always have good rooms to work with. And sometimes
> you have a customer who is obsessed with mono compatibility.
> --scott

I have only read one report from an engineer who used it. He said it was
"holographic".

--
shut up and play your guitar * HankAlrich.Com
HankandShaidriMusic.Com
YouTube.Com/WalkinayMusic

[Tom McCreadie]

Gary, I'm not really familiar with the details of your surround sound
shenanigans, but the following applies to straight two-channel stereo:

You will _always_ get an image lateral-inversion (your "channel reversal") of
certain rear-arriving sounds whenever you employ:
1. an XY array (except 180° back-to-back splayed) with mics of tighter pattern
than cardioid
or
2. an MS system that after decoding equates to the above array "1"

Why is this? The mic patterns in the above arrays always have a rear lobe of
negative polarity. And there will always exist some angular direction within the
rear right quadrant w.r.t. the array from which an arriving sound will deliver a
stronger mic signal via the negative lobe of the L-angled mic than via the
negative lobe of the R-angled sister mic.

Consider, for illustration, the classic ± 45° Blumlein. The axis of the rear
lobe of the L-angled mic (and the null of the R-angled mic) points to "4:30
o'clock". So a sound arriving from, say, 4:45 o'clock would deliver a strong
signal (albeit negative) into the L-channel, but a much wimpier signal (though
also negative) into the R-channel. Hence a sound source located at 4:45 o'clock
will image left of centre on two-speaker playback, i.e. as if it were located at
7:15 o'clock, i.e. lateral-inversion of image.

The actual angular width of this lateral-inversion rear sector varies with the
mic pattern, XY splay angle and M:S ratio....but there's never a
lateral-inversion when using omni in MS because an omni records all signals with
positive phase.

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

[Gary Eickmeier]

"Tom McCreadie" > wrote in message
...
> Gary, I'm not really familiar with the details of your surround sound
> shenanigans, but the following applies to straight two-channel stereo:
>
> You will _always_ get an image lateral-inversion (your "channel
> reversal") of
> certain rear-arriving sounds whenever you employ:
> 1. an XY array (except 180° back-to-back splayed) with mics of tighter
> pattern
> than cardioid
> or
> 2. an MS system that after decoding equates to the above array "1"
>
> Why is this? The mic patterns in the above arrays always have a rear lobe
> of
> negative polarity. And there will always exist some angular direction
> within the
> rear right quadrant w.r.t. the array from which an arriving sound will
> deliver a
> stronger mic signal via the negative lobe of the L-angled mic than via the
> negative lobe of the R-angled sister mic.
>
> Consider, for illustration, the classic ± 45° Blumlein. The axis of the
> rear
> lobe of the L-angled mic (and the null of the R-angled mic) points to
> "4:30
> o'clock". So a sound arriving from, say, 4:45 o'clock would deliver a
> strong
> signal (albeit negative) into the L-channel, but a much wimpier signal
> (though
> also negative) into the R-channel. Hence a sound source located at 4:45
> o'clock
> will image left of centre on two-speaker playback, i.e. as if it were
> located at
> 7:15 o'clock, i.e. lateral-inversion of image.
>
> The actual angular width of this lateral-inversion rear sector varies with
> the
> mic pattern, XY splay angle and M:S ratio....but there's never a
> lateral-inversion when using omni in MS because an omni records all
> signals with
> positive phase.

Yes, that is what my experiment confirmed, as expected. I just needed to
hear it for myself in an anechoic experiment and on my system.

Gary

[[email protected]]

amar

[geoff]

On 20/04/2020 5:02 pm, wrote:
> amar
>

I find the thought of MS rather unpleasant. A sister-in-law of mine has it.

If you got it wrong and meant SM, well that doesn't do much for me
either- don't like receiving or inflicting pain.

geoff

[polymod]

"geoff" wrote in message
...

On 20/04/2020 5:02 pm, wrote:
> amar
>

I find the thought of MS rather unpleasant. A sister-in-law of mine has it.

If you got it wrong and meant SM, well that doesn't do much for me
either- don't like receiving or inflicting pain.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

ROTFLMAO!

Poly