In article writes:

Reversing cardioid signals is hardly experimentation. Two card's can be
trusted as a 100% match when they produce no perceivable signal when one is
inverted against the other.

Since there is no way in the presently known universe to put two objects
in the same place at the same time, how can wavefronts that arrive at
different times null? Is this a fantasy test?

Everything in recorded audio is fantasy. Which fantasy do you like?
It's all a matter of how "close enough" do you want to get. Even if
you could put both microphones in the same place, you couldn't build
two capsules closely enough to identical so that they'd cancel
completely at all frequencies, from all angles. It's just a way to
check whether you're in the ballpark.

Grossly mismatched mics will give strange results when used as a
stereo pair. Mics that are pretty close will work quite well.

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo

ScotFraser wrote:

In the end, everything we do is slightly
approximate anyway, so what's a few millimeters this way or that?

Possibly quite a lot if looking for complete null with two opposite
polarity, separately housed cardioids?

--
ha

Mike Rivers wrote:

...snip..

Everything in recorded audio is fantasy. Which fantasy do you like?
It's all a matter of how "close enough" do you want to get. Even if
you could put both microphones in the same place, you couldn't build
two capsules closely enough to identical so that they'd cancel
completely at all frequencies, from all angles. It's just a way to
check whether you're in the ballpark.

Grossly mismatched mics will give strange results when used as a
stereo pair. Mics that are pretty close will work quite well.

--
I'm really Mike Rivers )

In example, I did an MS experiment with a bluegrass group
a few weeks ago. They play single mic style so recordings
would be in mono. To add some space to the (live) recording
(without detracting from their single mic look) I set up two
ATM-35 as the S output. [I did do some EQ to help match
the S and M response. Note: their single mic is an AT 4033
stuck in an old classic RCA shell, so I don't have a clue what it's
response is. (Then too, I wrote a vector analysis program that
display phase coherence info. to help with the EQ...) ]

Anyway, the added space greatly enhanced the recording.
In contrast, a friend's group just did a (single mic) studio
recording with reverb to add space ...and to me it just sounds
wrong.

In the art of recording YMMV is a key phrase. ;-)

Later...

Ron Capik
--

Ty Ford wrote:

Then there's the consideration of how the mic bodies might alter the results
because of their obstructional presence.

For sure. Grills and bodys have very large effects above 10
kHz. That's why I made my DIY MS a front address with an
axially symmetric body behind it. It's way too blunt but
that's what I had on hand. I've spent very little time at
this point evaluating that particular iteration. I know the
stereo image is good but haven't characterized the response.

If I were to ever build a commercial version of the the 3
capsule M/S I'd be paying special experimental attention to
that factor. I'd like to do one with the array at the end
of a body shaped like an Earthworks TC30K for example. One
of these days.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

ScotFraser wrote:
While they can't be at the same place,
they can be at the same distance by placing one atop the
other pointing in opposite directions with their diaphragms
in the same plane and with that plane passing through the
source. BRBR

Which is great for sound arriving from a single direction, i.e. an anechoic
situation. In any desirable recording venue, obviously the distance thing again
becomes slightly approximate.

Correct, but my thinking is that for the usual focus of
attention, the direct sound from what's arrayed in front and
to the sides, it will be pretty optimally captured from an
M/S relative delay standpoint and the diffuse or reverberant
sound arriving with a signifigant azimuth angle will be what
is time skewed. Since that part is naturally skewed with
strong frequency dependancy and without any kind of precise
image requirements, inaccuracy there shouldn't matter too
much. I may be wrong but I don't think the time coherence
of ambience is very important.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

Everything in recorded audio is fantasy. Which fantasy do you like?
It's all a matter of how "close enough" do you want to get. Even if
you could put both microphones in the same place, you couldn't build
two capsules closely enough to identical so that they'd cancel
completely at all frequencies, from all angles.

I've liked the sound I get from a U87 in Omni, and a Royer R121 as the
bi-directional mic. I doubt the two responses are similar enough for
mathematically 'perfect' MS, but the results sound 'good' to me.

KyleSong wrote:
Everything in recorded audio is fantasy. Which fantasy do you like?
It's all a matter of how "close enough" do you want to get. Even if
you could put both microphones in the same place, you couldn't build
two capsules closely enough to identical so that they'd cancel
completely at all frequencies, from all angles.


I've liked the sound I get from a U87 in Omni, and a Royer R121 as the
bi-directional mic. I doubt the two responses are similar enough for
mathematically 'perfect' MS, but the results sound 'good' to me.

Where you need to look for 'goodness' with respect to
matching is in the spatial distribution of instrument
images. If the M and S aren't matched in their response
curves then the reproduced image of an instrument that is
off axis can get quite blurred with some part of its
spectrum in one place and other parts in another place. M/S
is intensity based so if relative intensity is varying with
frequency so are the image locations. A few dB difference
in response at a frequency is like a few dB pan difference
at that frequency.

Percussion, being especially broad band, is particularly
sensitive to this mismatch effect.

If, OTOH, you are multi-tracking with MS and your source is
always on axis and compact so that you are relying on the S
for ambience only you won't be as sensitive to mismatch and
the MS panning plugins like Waves' "Stereo Imager" will
preserve the spatial coherence while rotating the image.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

Bob Cain wrote:

If, OTOH, you are multi-tracking with MS and your source is
always on axis and compact so that you are relying on the S
for ambience only you won't be as sensitive to mismatch and
the MS panning plugins like Waves' "Stereo Imager" will
preserve the spatial coherence while rotating the image.

Thanks for the point - I get it, and hadn't considered that before.

generally I do use MS in situations where most of the direct signal is in
front of the array, with most of the sides being ambience. In that case, I
like the color of the sound I get with the U87 and Royer R121. I'm guessing
that the 87 has more top, so perhaps high end will be biased to the middle
in this setup.

I hadn't encountered the situation of instruments to the side that you're
talking about, so if (when) that situation does arise, I'll listen hard for
discrepancies such as the ones you describe.

Thanks for the education.

Kyle

I may be wrong but I don't think the time coherence
of ambience is very important. BRBR

Right. I think we have a lot of leeway with ambience. I often delay ambience
tracks a bit to make them more incoherent, thus less colorizing to the direct
tracks.

Scott Fraser

Possibly quite a lot if looking for complete null with two opposite
polarity, separately housed cardioids? BRBR

That not nulled would be in the canine stratus frequency-wise, which is an area
where I think we have room for a lot of slop, vis a vis perceived accuracy.

Scott Fraser

"David Satz" wrote in message
om...
Sugarite wrote:

This is leading towards a debate over whether two matched cardioids
are in fact a truer match than either side of a fig-8. I'm of the
opinion that the matched card's are a truer match, mostly because you
can't as easily test the internal bipolar matching on a mic-by-mic
basis like matching two card's.

May I take a closer look at this rather mysterious course of logic? If
I didn't know better, I'd think you were saying that the ease of testing
which you imagine in a thought experiment (!) should take precedence over
the accuracy of competent real-world measurements.

But even granting that, I think your logical conclusion would be: "If I
had to document the front/back symmetry myself, I'd prefer two cardioids.
Then I'd have my own way to make the measurements, so I would feel more
comfortable trusting the results." Human to human, I could respect that.

Still, that isn't quite the same as the broad claim that "cardioids match
better than the front and back of a figure 8" (which is what you said).
The two statements are about different things--the first one is about
your own mindset, while the other one is about microphone capsules, no?

**** mindset. This isn't a philosophical issue. Take two cardioids, place
them side-by-side in front of any suitably complex sound source. If you
oppose the signals from the two mics and all you get is the mics'
self-noise, then they're matched with as much certainty as this industry
affords. Everything including any aberrations from the two mics being close
to each other would show up if they weren't matched close enough to be
called "perfect" for any reasonable application.

Show me a test that proves any fig-8 can be trusted to that level of
precision and I'll certainly consider it. The importance of matched mics
for what I do is pretty much paramount. Curves don't cut it.

Everything in recorded audio is fantasy. Which fantasy do you like?
It's all a matter of how "close enough" do you want to get. Even if
you could put both microphones in the same place, you couldn't build
two capsules closely enough to identical so that they'd cancel
completely at all frequencies, from all angles.

I've liked the sound I get from a U87 in Omni, and a Royer R121 as the
bi-directional mic. I doubt the two responses are similar enough for
mathematically 'perfect' MS, but the results sound 'good' to me.

Part of me wants to burn you at the stake for such a wanton mismatch, but at
the same time I applaud your achievement of self-satisfaction despite the
technical disparity.

It'd be nice to have two groups, rec.audio.pro.theory and
rec.audio.pro.practice, because there is so much daylight between the two
it's ****ing nauseating.

Sugarite wrote:

Take two cardioids, place
them side-by-side in front of any suitably complex sound source.

I've done that, with several different pairs of like mics, and I did not
get a truly decent null. All one must do is listen to how it sounds with
both mics in same polarity and then with one mic and notice there is a
difference, even with decently matched levels.

--
ha

Part of me wants to burn you at the stake for such a wanton mismatch, but at
the same time I applaud your achievement of self-satisfaction despite the
technical disparity.


Oooh burned Wantons - not a good grade in cooking school, but they taste SO
good

Seriously, thanks for the post.

I really DO have good ears, and I really DO like the sound. I generally use
it for drum ambience, so the color is a matter of taste. If I was doing this
with a string quartet, especially one that was spread out around the
microphone, then I'm sure I would choose differently.

The color of the room ambience on the drums is really great with this
combination, and like I said before, there isn't any source that's placed
outside of the front of the array, so the stereo placement isn't being
compromised.

(ScotFraser)
In the end, everything we do is slightly
approximate anyway, so what's a few millimeters this way or that?

The difference between how a KM184 and a KM140 sound, as according to
Neumann the capsule being placed a few millimeters different is the only
difference techincally between the two mics, one of which you have said you
much prefer over the other.... g Or maybe the difference between how some
dual capsule mics and some single capsule mic sound in omni, as the dual
capsule introduces just the teensiest bit of distance.

But anyway, if MS wasn't working for me I might think it was for reasons
other than a slight difference between the response on the front and back of my
chosen figure 8 mic.

Will Miho
NY Music & TV Audio Guy
Audioist / Fox News
"The large print giveth and the small print taketh away..." Tom Waits

(ScotFraser)
I often delay ambience
tracks a bit to make them more incoherent, thus less colorizing to the direct
tracks.

Do you roll off the low end a lot on your ambient tracks Scott?



Will Miho
NY Music & TV Audio Guy
Audioist / Fox News
"The large print giveth and the small print taketh away..." Tom Waits

"Sugarite"
Part of me wants to burn you at the stake for such a wanton mismatch, but at
the same time I applaud your achievement of self-satisfaction despite the
technical disparity.

It'd be nice to have two groups, rec.audio.pro.theory and
rec.audio.pro.practice, because there is so much daylight between the two
it's ****ing nauseating.

I get the impression your left brain is a lot more muscular than your
right brain is. The right brain relates better to what *is* though, and
sometimes the left brain being busy telling you what *should be* when you are
working will get in your way, impede your dealing with what is actually in
front of you.

Besides, do you have left and right EARS that are perfectly matched? I
hear 80hz much better on my left side than on my right, and have a dip at 2k of
a 1/2 db or so on that side as well, last time I had them tested.

Will Miho
NY Music & TV Audio Guy
Audioist / Fox News
"The large print giveth and the small print taketh away..." Tom Waits

The difference between how a KM184 and a KM140 sound, as according to
Neumann the capsule being placed a few millimeters different is the only
difference techincally between the two mics, one of which you have said you
much prefer over the other.... g BRBR

Actually I've never used a KM184 in a critical situation, so I don't have an
opinion about them. You must be thinking of some other guy named Scott.

Scott Fraser

ScotFraser wrote:
The difference between how a KM184 and a KM140 sound, as according to
Neumann the capsule being placed a few millimeters different is the only
difference techincally between the two mics, one of which you have said you
much prefer over the other.... g BRBR

Actually I've never used a KM184 in a critical situation, so I don't have an
opinion about them. You must be thinking of some other guy named Scott.

It was probably me. I like the KM140 better.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

(ScotFraser)

Actually I've never used a KM184 in a critical situation, so I don't have
anopinion about them. You must be thinking of some other guy named Scott.

Actually you did say so once Scott, at least by deductive reasoning. You
said in a U87 thread that comparing a KM184 to a Scheops CM62 was unfair due to
the cost differential, that a comparison to a KM140 was a closer comparison,
and that you "slightly prefer the depiction of the upper bass range of the
KM140."

Not to bust your chops or anything... g


Will Miho
NY Music & TV Audio Guy
Audioist / Fox News
"The large print giveth and the small print taketh away..." Tom Waits

"Sugarite" wrote in message
...
**** mindset. This isn't a philosophical issue. Take two cardioids,
place
them side-by-side in front of any suitably complex sound source. If you
oppose the signals from the two mics and all you get is the mics'
self-noise, then they're matched with as much certainty as this industry
affords. Everything including any aberrations from the two mics being
close
to each other would show up if they weren't matched close enough to be
called "perfect" for any reasonable application.

Show me a test that proves any fig-8 can be trusted to that level of
precision and I'll certainly consider it. The importance of matched mics
for what I do is pretty much paramount. Curves don't cut it.

I have to wonder how you could get the two mics to occupy the EXACT same
space at the same time to perform such a test?
Side by side don't cut it either.

TonyP.

"TonyP" wrote in message
u

I have to wonder how you could get the two mics to occupy the EXACT
same space at the same time to perform such a test?
Side by side don't cut it either.

As close as you'll get practially might be obtained by using miniature
mics. I followed up on some recent posts about Knowles mics that Digi Key
has in their catalog and found that they are actually 0.1" OD. Those were
omnis, but I think they also have some really small directional mics in
their catalog.

My point being that 1" mics quite obviously can't be coincident at paractial
audio frequencies, and IME neither can 1/2" mics. However, practially nearly
coincident up to say 10 KHz could solve a lot of problems.

The wavelength of 10 KHz is something like 1.3 inches, so mics that are 0.1"
center to center are still about 30 degrees apart in terms of phase. The
good news is that 30 degrees is a long ways from 180 degrees. The cosine of
this angle is almost 0.9, so cancellation on the order of 20 dB at 10 KHz
seems possible.

"Arny Krueger" wrote in
:

The wavelength of 10 KHz is something like 1.3 inches, so mics that
are 0.1" center to center are still about 30 degrees apart in terms of
phase. The good news is that 30 degrees is a long ways from 180
degrees. The cosine of this angle is almost 0.9, so cancellation on
the order of 20 dB at 10 KHz seems possible.

Also, we're not interested in the stereo effect of vertical spacing. Most
sources are spread in the horizontal plane, so having mics coincident
vertically is usually enough.

A pair of side address mics, one atop the other can get very close
vertically and almost precisely aligned horizontally (to the limitation of
the width of the capsule).

Arny Krueger wrote:

As close as you'll get practially might be obtained by using miniature
mics.

Whereas in practicality we might want to use some other type of mic. I
guess I'm just sceptical about the usefulness of trying to null
separate, real world and of various size, cardioid mic pairs. IME it
hasn't worked well. Maybe that's just another reason folks bother to
build anechoic chambers.

--
ha

Do you roll off the low end a lot on your ambient tracks Scott?
BRBR

I don't really have a blanket policy on that, it's really on a case by case
basis, but probably a low rolloff is unconsciously in place due to mic choice,
since I'm more interested in mid & higher response in the ambient tracks.
Scott Fraser

hank alrich wrote:

Arny Krueger wrote:

As close as you'll get practially might be obtained by using miniature
mics.

Whereas in practicality we might want to use some other type of mic. I
guess I'm just sceptical about the usefulness of trying to null
separate, real world and of various size, cardioid mic pairs. IME it
hasn't worked well. Maybe that's just another reason folks bother to
build anechoic chambers.
--
ha

All this "phonons dancing on the head of a pin" stuff has me wondering
what has become of the usual mantra of this group: use your ears... ?

If one needs to account for and correct every little phase anomaly in
the system before they record they'd never get any recording done.

In my experience theory helps but the real proof is in the experimental
(or in this case recording) results.

[OK, I'll admit some of these techno-flame-wars are fun to follow. ]

Later...

Ron Capik cynic in training
--

Ron Capik wrote:

All this "phonons dancing on the head of a pin" stuff has me wondering
what has become of the usual mantra of this group: use your ears... ?

I guess a paraphrasation of what's talking here is trying to get at
audible image anomalies when using an M/S config. The tangent developed
around the question of useful null from separate cardioids. My points
remain that I have no interest in laboratory results using the tiniest
available cardioids because the liklihood of me wanting to use those in
recording work is low, and that I have little faith in the achievement
of null with the real world mics, having been there and done that.

If one needs to account for and correct every little phase anomaly in
the system before they record they'd never get any recording done.

Right, but in the context of stable imaging across the spectrum, little
phase anomalies can make larger than expected differences.

In my experience theory helps but the real proof is in the experimental
(or in this case recording) results.

Amen.

[OK, I'll admit some of these techno-flame-wars are fun to follow. ]

You're a sick man, Ron, but you knew that already.

Later...

Ron Capik cynic in training

The Cynical Olympics, new on FOX!

--
ha

Ron Capik wrote:

All this "phonons dancing on the head of a pin" stuff has me wondering
what has become of the usual mantra of this group: use your ears... ?

I guess a paraphrasation of what's talking here is trying to get at
audible image anomalies when using an M/S config. The tangent developed
around the question of useful null from separate cardioids. My points
remain that I have no interest in laboratory results using the tiniest
available cardioids because the liklihood of me wanting to use those in
recording work is low, and that I have little faith in the achievement
of null with the real world mics, having been there and done that.

If one needs to account for and correct every little phase anomaly in
the system before they record they'd never get any recording done.

Right, but in the context of stable imaging across the spectrum, little
phase anomalies can make larger than expected differences.

In my experience theory helps but the real proof is in the experimental
(or in this case recording) results.

Amen.

[OK, I'll admit some of these techno-flame-wars are fun to follow. ]

You're a sick man, Ron, but you knew that already.

Later...

Ron Capik cynic in training

The Cynical Olympics, new on FOX!

--
ha

Ron Capik wrote:

In my experience theory helps but the real proof is in the experimental
(or in this case recording) results.

I agree. Knowing and understanding audio theory will help you make informed
decisions, and give you a good set of options to choose from. Ditto
experience. But each of these is only a starting point. There is not "Art by
Number" method that will produce great results every time.

This is not an argument for ignorance. You must have both: a good
understanding of what is happening and is possible, AND an open mind and
open set of ears to hear how its sounding THIS time.

In my opinion, the hardest thing about any art is to keep your
experience/technique handy, but not in the driver's seat. This means
avoiding the bias that knowledge brings, while still using it to your
advantage.

For instance, if you spend $4,000 on a beautiful tube compressor, and you
come to a track that is the sort of thing that you bought that piece FOR, it
is a VERY difficult thing to admit to yourself (and hear) that in this case,
the device is not working as well as something else.

Another example is avoiding the theoretical 'misuse' of unmatched
microphones in an M/S array that just happens to sound 'good'.

The dilemma is in having good knowledge / experience to draw from, and
listening like its the first time, all at once. This is the basic struggle
of any artist in any medium. To have the chops to do it well, and at the
same time, to let your subconscious voice lead the way.

The purpose of art is to create an emotional (and / or intellectual)
response in the audience. Technique helps in creation, but it is the result
that matters.

You will do better work on a more consistent basis with knowledge. But your
work will be best if it speaks to humanity, and that is something that
cannot be quantified in technique alone.

Since I don't believe that there has EVER been a recording that sounded like
musicians playing live in a room, I think that all recordings are on some
level impressionistic. Even if the result is intended to mimic a natural
experience, it may well be through the judicious application of several
processes that the most "natural" feeling recording results.

Based on this belief, I don't think you can argue science past a certain
point in audio. You can argue HOW something works, but it is how it sounds
that matters in the end. Of course "how it works" informs "how it sounds",
so again, this is not an argument, or an excuse for ignorance. I'm not
saying "**** science, it only matters how it sounds" but I AM saying that
science alone cannot describe the entirety of what we are all trying to do
here, and that when theory becomes in opposition to results that are ideal
for a certain musical application, that the science must step aside to
accommodate the human artistic experience.

Ron Capik wrote:

In my experience theory helps but the real proof is in the experimental
(or in this case recording) results.

I agree. Knowing and understanding audio theory will help you make informed
decisions, and give you a good set of options to choose from. Ditto
experience. But each of these is only a starting point. There is not "Art by
Number" method that will produce great results every time.

This is not an argument for ignorance. You must have both: a good
understanding of what is happening and is possible, AND an open mind and
open set of ears to hear how its sounding THIS time.

In my opinion, the hardest thing about any art is to keep your
experience/technique handy, but not in the driver's seat. This means
avoiding the bias that knowledge brings, while still using it to your
advantage.

For instance, if you spend $4,000 on a beautiful tube compressor, and you
come to a track that is the sort of thing that you bought that piece FOR, it
is a VERY difficult thing to admit to yourself (and hear) that in this case,
the device is not working as well as something else.

Another example is avoiding the theoretical 'misuse' of unmatched
microphones in an M/S array that just happens to sound 'good'.

The dilemma is in having good knowledge / experience to draw from, and
listening like its the first time, all at once. This is the basic struggle
of any artist in any medium. To have the chops to do it well, and at the
same time, to let your subconscious voice lead the way.

The purpose of art is to create an emotional (and / or intellectual)
response in the audience. Technique helps in creation, but it is the result
that matters.

You will do better work on a more consistent basis with knowledge. But your
work will be best if it speaks to humanity, and that is something that
cannot be quantified in technique alone.

Since I don't believe that there has EVER been a recording that sounded like
musicians playing live in a room, I think that all recordings are on some
level impressionistic. Even if the result is intended to mimic a natural
experience, it may well be through the judicious application of several
processes that the most "natural" feeling recording results.

Based on this belief, I don't think you can argue science past a certain
point in audio. You can argue HOW something works, but it is how it sounds
that matters in the end. Of course "how it works" informs "how it sounds",
so again, this is not an argument, or an excuse for ignorance. I'm not
saying "**** science, it only matters how it sounds" but I AM saying that
science alone cannot describe the entirety of what we are all trying to do
here, and that when theory becomes in opposition to results that are ideal
for a certain musical application, that the science must step aside to
accommodate the human artistic experience.