ORTF and panning L/R

[Guest]

Archived from groups: rec.audio.pro (More info?)

Here's something I'm wondering about.
Is panning far left and far right the best thing to do when recording 2
stereo tracks?
or should it be 40 min and 20 min, or 45 min and 15 min, or should I just
leave both tracks centered, or is it all purely subjective?
My ORTF configuration is sounding pretty good just leaving it centered, but
it also sounds pretty good panning wide.
Is there a "correct" way to get the most realistic stereo sound?

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

"offpeak808" <offpeak808@hotmail.com> wrote in message
news:cj2mpq$rcu$1@jupiter.ttn.net...
> Here's something I'm wondering about.
> Is panning far left and far right the best thing to do when recording 2
> stereo tracks?
> or should it be 40 min and 20 min, or 45 min and 15 min, or should I just
> leave both tracks centered, or is it all purely subjective?
> My ORTF configuration is sounding pretty good just leaving it centered,
but
> it also sounds pretty good panning wide.
> Is there a "correct" way to get the most realistic stereo sound?

ORTF is predicated on panning L&R. If you pan both microphones to the
center, you have mono, with cancellations, and if that's what you want,
you'd be better off just pointing a single wide cardioid forward.

Peace,
Paul

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

offpeak808 <offpeak808@hotmail.com> wrote:
>Here's something I'm wondering about.
>Is panning far left and far right the best thing to do when recording 2
>stereo tracks?

Yes.

>or should it be 40 min and 20 min, or 45 min and 15 min, or should I just
>leave both tracks centered, or is it all purely subjective?

If you leave them both centered, you get mono. There's nothing wrong with
mono, but if you want mono, a single omni will sound better than ORTF rolled
to mono in most cases. If you are using ORTF, you probably don't want mono.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

"offpeak808" <offpeak808@hotmail.com> wrote in
news:cj2mpq$rcu$1@jupiter.ttn.net:

> Here's something I'm wondering about.
> Is panning far left and far right the best thing to do when recording
> 2 stereo tracks?
> or should it be 40 min and 20 min, or 45 min and 15 min, or should I
> just leave both tracks centered, or is it all purely subjective?
> My ORTF configuration is sounding pretty good just leaving it
> centered, but it also sounds pretty good panning wide.
> Is there a "correct" way to get the most realistic stereo sound?

You pan the channels far L&R.

If you want to adjust the stereo spread, you change the angle of the
microphones. Pointing them farther away from each other centers the
signal. Pointing them more toward the center widens the stereo field.

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

That's exactly what I wanted to know!
Thanks everyone.
We've been making some terrific recordings at the club thanks to Scott's
microphone advice.

"Carey Carlan" <gulfjoe@hotmail.com> wrote in message
news:Xns956FD1F7D2010gulfjoehotmailcom@207.69.189.193...
> "offpeak808" <offpeak808@hotmail.com> wrote in
> news:cj2mpq$rcu$1@jupiter.ttn.net:
>
> > Here's something I'm wondering about.
> > Is panning far left and far right the best thing to do when recording
> > 2 stereo tracks?
> > or should it be 40 min and 20 min, or 45 min and 15 min, or should I
> > just leave both tracks centered, or is it all purely subjective?
> > My ORTF configuration is sounding pretty good just leaving it
> > centered, but it also sounds pretty good panning wide.
> > Is there a "correct" way to get the most realistic stereo sound?
>
> You pan the channels far L&R.
>
> If you want to adjust the stereo spread, you change the angle of the
> microphones. Pointing them farther away from each other centers the
> signal. Pointing them more toward the center widens the stereo field.

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Pointing them farther away from each other centers the
> signal. Pointing them more toward the center widens the stereo field.

This seems counter-intuitive to me. Care to explain?


Thanks


Ty

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

TYY wrote:
> Pointing them farther away from each other centers the
>
>>signal. Pointing them more toward the center widens the stereo field.
>
>
> This seems counter-intuitive to me. Care to explain?
>
>
> Thanks
>
>
> Ty

Me too. And I would like to know because I use it every week, admittedly
only to liven up a mono feed from the board. What I have done so far is
borrow a couple of condensers, stuck them on a stereo bar in approx.
ORTF, and mix the resulting stereo track into the recording (of the
Pastor's sermon) during editing. Seems to work, but I am no expert.

--
Phil Nelson

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

tyler@dhiw.com (TYY) wrote in
news:b6b7a391.0409261539.65e57fcd@posting.google.com:

> Pointing them farther away from each other centers the
>> signal. Pointing them more toward the center widens the stereo field.
>
> This seems counter-intuitive to me. Care to explain?

It is absolutely counter-intuitive, but intuition has to take a back seat
to reason. Think of the arc covered by the microphones as the range of
sounds that will sound centered between the channels.

If you point both microphones near the middle (say 30 degrees), then almost
everything to the left is left of the left channel and almost everything to
the right is right of the right channel. The stereo field is much wider
than the microphone spread.

If you spread the mics wide (say 135 degrees) nearly everything in the
stereo field is between the microphones (right of left and left of right)
effectively narrowing the stereo field leaving the speakers.

Two "buts"

1) Wide stereo field requires a mic with good off-axis response. I use
Schoeps.
2) If you keep narrowing the angle, the effect eventually collapses to
mono.

I heard someone mention this phenomenon a while back on RAP and didn't
believe it until I tried it.

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Carey Carlan wrote:

> tyler@dhiw.com (TYY) wrote in
> news:b6b7a391.0409261539.65e57fcd@posting.google.com:
>
>>Pointing them farther away from each other centers the
>>>signal. Pointing them more toward the center widens the stereo field.
>>
>>This seems counter-intuitive to me. Care to explain?
>
>
> It is absolutely counter-intuitive, but intuition has to take a back seat
> to reason. Think of the arc covered by the microphones as the range of
> sounds that will sound centered between the channels.
>
> If you point both microphones near the middle (say 30 degrees), then almost
> everything to the left is left of the left channel and almost everything to
> the right is right of the right channel. The stereo field is much wider
> than the microphone spread.
>
> If you spread the mics wide (say 135 degrees) nearly everything in the
> stereo field is between the microphones (right of left and left of right)
> effectively narrowing the stereo field leaving the speakers.
>
> Two "buts"
>
> 1) Wide stereo field requires a mic with good off-axis response. I use
> Schoeps.
> 2) If you keep narrowing the angle, the effect eventually collapses to
> mono.
>
> I heard someone mention this phenomenon a while back on RAP and didn't
> believe it until I tried it.

Hmmm. If narrowing the angle leads to mono, and widening the angle
eventually reduces the stereo effect as well, then there must be some
theoretically optimal angle for maximum stereo effect. Is that the
"official" 110 degrees that is often associated with ORTF? Intuitively,
I would expect it to be smaller than that.

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

>
> I heard someone mention this phenomenon a while back on RAP and didn't
> believe it until I tried it.

I too must verify to believe! I have been using ORTF for drum OH and
have been getting good results. This new theory will definitely alter
how I tweak mic positioning on my next drum tracking session.

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

In article <b6b7a391.0409261539.65e57fcd@posting.google.com>,
TYY <tyler@dhiw.com> wrote:
>Pointing them farther away from each other centers the
>> signal. Pointing them more toward the center widens the stereo field.
>
>This seems counter-intuitive to me. Care to explain?

Greater differences between channels gives you a wider soundfield.

Pointing them both together gives you mono.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Look at this

http/www.microphone-data.com/pdfs/Stereo%20zoom.pdf

Jean-Marie Mathieu

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

This is still not making sense to me, especially if I use logic in
addition to intuition.


The narrower the angle between the mics, the more sound information
will be shared between the two mics (assuming cardioid mics, of
course), and the image should be narrower. A more obtuse angle between
the mics would result in greater difference in what the mic is seeing,
giving a wider image, no?

What if you point two cardiod mics 180s away from each other. This
should give a wide image because each mic is picking up different
sounds, i.e. very little information is "shared" between the two mics.
Clearly two card mics parallel are almost acting as one microphone,
giving a virtually mono recording. How do angles in between 0 and 180
somehow run counter to this trend?

I guess I'll have to do some experimenting...

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

> >This seems counter-intuitive to me. Care to explain?
>
> Greater differences between channels gives you a wider soundfield.
>
> Pointing them both together gives you mono.
> --scott

My last post was made before I read your post scott (damn google).

You seem to have the same opinion I have. Please read the post under
question more closely. You will see that your statement runs counter
to the argument made. He stated that wider image is produced by a
narrower angle between mikes. This will give less differences between
channels, no?

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Jim Gilliland <usemylastname@cheerful.com> wrote in
news:vsqdnZNY_awLb8rcRVn-sA@adelphia.com:

> Hmmm. If narrowing the angle leads to mono, and widening the angle
> eventually reduces the stereo effect as well, then there must be some
> theoretically optimal angle for maximum stereo effect. Is that the
> "official" 110 degrees that is often associated with ORTF?
> Intuitively, I would expect it to be smaller than that.

IME, using hypercardioid Schoeps CMC641's, the soundfield is widest at
about a 30 degree spread. The angle will be wider with wider pattern mics.

Starting at a very wide mic spread and a narrow stereo spread, the stereo
spread widens continually until the two mic patterns almost overlap
completely. Then it rather suddenly collapses to mono.

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Carey Carlan wrote:
> Jim Gilliland <usemylastname@cheerful.com> wrote in
> news:vsqdnZNY_awLb8rcRVn-sA@adelphia.com:
>
>>Hmmm. If narrowing the angle leads to mono, and widening the angle
>>eventually reduces the stereo effect as well, then there must be some
>>theoretically optimal angle for maximum stereo effect. Is that the
>>"official" 110 degrees that is often associated with ORTF?
>>Intuitively, I would expect it to be smaller than that.
>
> IME, using hypercardioid Schoeps CMC641's, the soundfield is widest at
> about a 30 degree spread. The angle will be wider with wider pattern mics.
>
> Starting at a very wide mic spread and a narrow stereo spread, the stereo
> spread widens continually until the two mic patterns almost overlap
> completely. Then it rather suddenly collapses to mono.

I appreciate the benefit of your experience here. But that begs the
obvious question - what is the theoretical basis for the 110 degrees
that is commonly cited as the ORTF standard? Obviously, they weren't
going for maximum stereo effect.

As you observe, standard cardioid patterns would give their maximum
stereo at an angle larger than 30, but I'm sure it would be nowhere near
110. So the ORTF must have been going for some sort of balance -
perhaps just a "natural" sense of stereo, unexaggerated?

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

In article <ft-dndnOi-iMrsXcRVn-tw@adelphia.com> usemylastname@cheerful.com writes:

> I appreciate the benefit of your experience here. But that begs the
> obvious question - what is the theoretical basis for the 110 degrees
> that is commonly cited as the ORTF standard? Obviously, they weren't
> going for maximum stereo effect.

The theoretical answer, which I can't substantiate but I'm sure
someone here can (and will) is that it has to do with the coverage
pattern (hypercardioid, I think - been a while since I've written that
article or used that setup) of the mics that were used for the
'standard' ORTF setup.

The more practical answer is that this is what works in the way the
setup is most often used. It's appropriate for a source as wide as an
orchestra, with the mic placed some distance away. Putting a
near-coincident array up close to a guitar, or relatively close as
with drum overheads doesn't make it ORTF even if the mics are the
right pattern spaced at 110 degrees. It's just two mics pointing in
different directions.

As most people who work with this kind of setup will tell you, the 110
degree angle is a starting point. You should be prepared to make
adjustments in position and angle based on what you hear.


--
I'm really Mike Rivers (mrivers@d-and-d.com)
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 here: double-m-eleven-double-zero at yahoo

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

mrivers@d-and-d.com (Mike Rivers) wrote in news:znr1096305108k@trad:

> The theoretical answer, which I can't substantiate but I'm sure
> someone here can (and will) is that it has to do with the coverage
> pattern (hypercardioid, I think - been a while since I've written that
> article or used that setup) of the mics that were used for the
> 'standard' ORTF setup.

I believe it has something to do with the -3 dB level on the two
microphones. On standard cardioids at 130 degree separation, the exact
center is down -3 dB on both channels, summing to zero across the pair.
For hypercardioids it's less and it may be 110 degrees.

> The more practical answer is that this is what works in the way the
> setup is most often used. It's appropriate for a source as wide as an
> orchestra, with the mic placed some distance away. Putting a
> near-coincident array up close to a guitar, or relatively close as
> with drum overheads doesn't make it ORTF even if the mics are the
> right pattern spaced at 110 degrees. It's just two mics pointing in
> different directions.

Agreed. I use ORTF as my default setup because it comes across wonderfully
on headphones and makes an excellent spread on speakers as well. The
microhpone spread depends on three factors:
1) the directionality of the microphones
2) the distance from the group to the mics
3) the size of the group.

Tighter patterns, greater distance, and/or smaller groups indicate narrower
spreads.

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

tyler@dhiw.com (TYY) wrote in
news:b6b7a391.0409270914.4609ec52@posting.google.com:

> This is still not making sense to me, especially if I use logic in
> addition to intuition.
>
>
> The narrower the angle between the mics, the more sound information
> will be shared between the two mics (assuming cardioid mics, of
> course), and the image should be narrower. A more obtuse angle between
> the mics would result in greater difference in what the mic is seeing,
> giving a wider image, no?
>
> What if you point two cardiod mics 180s away from each other. This
> should give a wide image because each mic is picking up different
> sounds, i.e. very little information is "shared" between the two mics.
> Clearly two card mics parallel are almost acting as one microphone,
> giving a virtually mono recording. How do angles in between 0 and 180
> somehow run counter to this trend?
>
> I guess I'll have to do some experimenting...

A thought experiment. Imagine a rhythm guitar on the right, vocal center,
and the bass on the left, each with a single amp. Left, center, and right
discrete sound sources.

If I point one directional mic right at the guitar and another at the bass,
they'll be in separate channels (far left and right) and each will share a
portion of the vocal. That's much like the narrow mic spread with a wide
stereo image.

If I point one mic left of the left instrument and another right of the
right instrument, I won't have *anything* in the direct path of the mic,
but I'll have fringes of everything in both channels. All three sources
will be left of the right mic and right of the left mic. That's the
definition of a narrow stereo image.

A second thought experiment for those who aren't yet convinced:

Your speakers are set in a stereo pattern, nominally at the corners of an
equilateral triangle with your console seat. That angle is fixed. What
effect does that have on the stereo image of microphones? A narrow angle
is widened, and a wide angle is narrowed.

Finally:

It is absolutely true that if you narrow the angle enough, the stereo image
collapses entirely and you get mono. But that happens rather suddenly and
at a small angle which varies with the mic pattern.

Epilogue

I'm offering these to satisfy the curious, but the real solution is to try
it. I didn't believe it myself until I tried it. It is now well
documented in my music library at least. See the "David Satz wins again"
thread I started back in March 2003. I was force to record too close and
set the mics too wide and damn if the image wasn't all that bad. More
experimentation later confirmed it.

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

>
> If I point one mic left of the left instrument and another right of the
> right instrument, I won't have *anything* in the direct path of the mic,
> but I'll have fringes of everything in both channels. All three sources
> will be left of the right mic and right of the left mic. That's the
> definition of a narrow stereo image.
>

This one definitely makes sense to me. The other piece of the puzzle
which hasn't been discussed enough is the proximity to the sound
source. Depending on distance to the guitar vocal and bass, the effect
of mic angle changes significantly. We are making some assumptions
about ORTF placement and distance to the source.

For closer applications (i.e. drum overheads), a wider mic spread may
indeed result in a wide image.