[Richard Corfield]

If the image seems too wide, in that actors go towards the edges too
easily rather than stay in the middle, do I need to make the microphones
wider angled or narrower? My guess narrower. I'm at about +-45deg at the
moment on a bar just forward of the stage so quite close to the action.
It means that the angular size of the action is somewhere around 130deg.

Listening to the playback it sounds pretty good, with both mechanical and
electrical noise from the lights on the bar not noticeable. We've had
to move a couple of lights closer to the mics to get the right lighting
effect so we'll see. They made lovely clanking noises after last night
when things cooled down.

Thanks

- Richard

--
_/_/_/ _/_/_/ _/_/_/ Richard Corfield
_/ _/ _/ _/
_/_/ _/ _/ Time is a one way street,
_/ _/ _/_/ _/_/_/ except in the Twilight Zone

[Don Pearce]

On Mon, 11 Feb 2008 08:17:52 GMT, Richard Corfield
wrote:

If the image seems too wide, in that actors go towards the edges too
easily rather than stay in the middle, do I need to make the microphones
wider angled or narrower? My guess narrower. I'm at about +-45deg at the
moment on a bar just forward of the stage so quite close to the action.
It means that the angular size of the action is somewhere around 130deg.

Listening to the playback it sounds pretty good, with both mechanical and
electrical noise from the lights on the bar not noticeable. We've had
to move a couple of lights closer to the mics to get the right lighting
effect so we'll see. They made lovely clanking noises after last night
when things cooled down.

Move them in - every time! You will find that you still get a
perfectly good image at +/- 30 deg. And the best thing is that actors
at centre stage aren't working so far off the mic axis, and they will
be reproduced better. Most of the problem you are experiencing is to
do with the highs - particularly sibilants. When you move even a
little way off the axis of one mic, you are getting better centred on
the other, and the top end response lifts dis proportionately.

If you have the option available, always the smallest diameter mics
possible for ORTF, because they will have the best off-axis response -
which will give you the best image.

d

--
Pearce Consulting
http://www.pearce.uk.com

[Richard Corfield]

On 2008-02-11, Don Pearce wrote:
If the image seems too wide, in that actors go towards the edges too
easily rather than stay in the middle, do I need to make the microphones
wider angled or narrower? My guess narrower. I'm at about +-45deg at the
moment on a bar just forward of the stage so quite close to the action.
It means that the angular size of the action is somewhere around 130deg.

Listening to the playback it sounds pretty good, with both mechanical and
electrical noise from the lights on the bar not noticeable. We've had
to move a couple of lights closer to the mics to get the right lighting
effect so we'll see. They made lovely clanking noises after last night
when things cooled down.

Move them in - every time! You will find that you still get a
perfectly good image at +/- 30 deg. And the best thing is that actors
at centre stage aren't working so far off the mic axis, and they will
be reproduced better. Most of the problem you are experiencing is to
do with the highs - particularly sibilants. When you move even a
little way off the axis of one mic, you are getting better centred on
the other, and the top end response lifts dis proportionately.

If you have the option available, always the smallest diameter mics
possible for ORTF, because they will have the best off-axis response -
which will give you the best image.

Thanks. It's dress rehearsal tonight so I can give that a go. The band
are far left though so taking them too far off axis could hinder things.

The mics are Behringer C2 - cheap but not bad for the price actually.
Apparently Behringer fixed the output circuit last year some time so
noise isn't such a problem. These are on quite a long cable run.

- Richard

--
_/_/_/ _/_/_/ _/_/_/ Richard Corfield
_/ _/ _/ _/
_/_/ _/ _/ Time is a one way street,
_/ _/ _/_/ _/_/_/ except in the Twilight Zone

[Don Pearce]

On Mon, 11 Feb 2008 10:14:25 GMT, Richard Corfield
wrote:

On 2008-02-11, Don Pearce wrote:
If the image seems too wide, in that actors go towards the edges too
easily rather than stay in the middle, do I need to make the microphones
wider angled or narrower? My guess narrower. I'm at about +-45deg at the
moment on a bar just forward of the stage so quite close to the action.
It means that the angular size of the action is somewhere around 130deg.

Listening to the playback it sounds pretty good, with both mechanical and
electrical noise from the lights on the bar not noticeable. We've had
to move a couple of lights closer to the mics to get the right lighting
effect so we'll see. They made lovely clanking noises after last night
when things cooled down.

Move them in - every time! You will find that you still get a
perfectly good image at +/- 30 deg. And the best thing is that actors
at centre stage aren't working so far off the mic axis, and they will
be reproduced better. Most of the problem you are experiencing is to
do with the highs - particularly sibilants. When you move even a
little way off the axis of one mic, you are getting better centred on
the other, and the top end response lifts dis proportionately.

If you have the option available, always the smallest diameter mics
possible for ORTF, because they will have the best off-axis response -
which will give you the best image.

Thanks. It's dress rehearsal tonight so I can give that a go. The band
are far left though so taking them too far off axis could hinder things.

The mics are Behringer C2 - cheap but not bad for the price actually.
Apparently Behringer fixed the output circuit last year some time so
noise isn't such a problem. These are on quite a long cable run.

- Richard

Ah - the band could be a problem. If they aren't too big, could you
perhaps spot mic them with a third mic and pan it in hard left. Start
with it at zero level, and bring it up just far enough to add a little
clarity to the music, just don't try and make it the main source of
band sound.

d

--
Pearce Consulting
http://www.pearce.uk.com

[Arny Krueger]

"Richard Corfield" wrote in
message
nal.littondale.dyndns.org

If the image seems too wide, in that actors go towards
the edges too easily rather than stay in the middle, do I
need to make the microphones wider angled or narrower? My
guess narrower. I'm at about +-45deg at the moment on a
bar just forward of the stage so quite close to the
action. It means that the angular size of the action is
somewhere around 130deg.

You've missed the whole point of microphone placement - you are supposed to
discover that by trying different angles and listening!

You also need to learn how to compensate for suboptimal angles during
editing and mixing.

[Mike Rivers]

On Feb 11, 3:17 am, Richard Corfield
wrote:
If the image seems too wide, in that actors go towards the edges too
easily rather than stay in the middle, do I need to make the microphones
wider angled or narrower?

The simple answer is that there is only one "official" ORTF
configuration. Cardioid microphones at an included angle of 110
degrees, positioned so that at this angle, the capsules are 17
centimeters apart. Anything else and it is no longer ORTF. You are
supposed to place the mics so that you capture what you want.

Knowing that this is not always possible, you just listen while moving
the mics until you get the coverage and stereo field that you want. Be
sure to check the sound when left and right channels are combined to
mono to be sure that nothing important drops out.

[Richard Corfield]

On 2008-02-11, Soundhaspriority wrote:
Richard,
Here's a classic article on the subject:
http://www.microphone-data.com/pdfs/Stereo%20zoom.pdf


Thanks. I've printed that off and will have a good read.

- Richard

--
_/_/_/ _/_/_/ _/_/_/ Richard Corfield
_/ _/ _/ _/
_/_/ _/ _/ Time is a one way street,
_/ _/ _/_/ _/_/_/ except in the Twilight Zone

[David Grant]

"Richard Corfield" wrote in message
nal.littondale.dyndns.org...
If the image seems too wide, in that actors go towards the edges too
easily rather than stay in the middle, do I need to make the microphones
wider angled or narrower? My guess narrower. I'm at about +-45deg at the
moment on a bar just forward of the stage so quite close to the action.
It means that the angular size of the action is somewhere around 130deg.


You don't mention the capsul-to-capsul distance. In any case, if you have
too much at the outer extents of the image then you want to either

a) angle the mics inwards, and/or
b) maintain your current angle but bring the mics closer together

[Adrian Tuddenham]

Richard Corfield wrote:

If the image seems too wide, in that actors go towards the edges too
easily rather than stay in the middle,...

When the rush is over, go to your library and read:

"Two-Channel Stereophonic Sound Systems" by F.H. Brittain and D.M.
Leakey. Wireless World. Vol 62 (May 1956) pp.206 - 210

Their experiments were done with panned mono and a classic Blumlein
array, but the results show that a lot of the image posititoning
problems are not caused by the mic set-up but are actually inherent in
the two-loudspeaker playback arrangement.


This raises the old question of whether the recording engineer should
distort his recording in order to compensate for the defects of the
reproducing suystem.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

[Don Pearce]

On Mon, 11 Feb 2008 08:17:52 GMT, Richard Corfield
wrote:

If the image seems too wide, in that actors go towards the edges too
easily rather than stay in the middle, do I need to make the microphones
wider angled or narrower? My guess narrower. I'm at about +-45deg at the
moment on a bar just forward of the stage so quite close to the action.
It means that the angular size of the action is somewhere around 130deg.

Listening to the playback it sounds pretty good, with both mechanical and
electrical noise from the lights on the bar not noticeable. We've had
to move a couple of lights closer to the mics to get the right lighting
effect so we'll see. They made lovely clanking noises after last night
when things cooled down.

Thanks

- Richard

Richard, I've just remembered a technique I saw used an awful long
time ago when the BBC were recording a stage drama. They used three
mics in a sort of ORTF plus one in the middle (a bit like a Decca
Tree, but co-located). That allowed them to put the two side mics
pointed at at quite a wide angle - about 150 degrees total I think.
The centre mic pointed straight forwards. They were then mixed with
the side mics panned hard left and right, and the centre mic panned to
centre. This resulted in a very natural spread of images, with good
tone balance all the way across. Worth a try, I think if you can get
hold of a third mic.

d

--
Pearce Consulting
http://www.pearce.uk.com

[Richard Corfield]

On 2008-02-12, Adrian Tuddenham wrote:

When the rush is over, go to your library and read:

"Two-Channel Stereophonic Sound Systems" by F.H. Brittain and D.M.
Leakey. Wireless World. Vol 62 (May 1956) pp.206 - 210

Their experiments were done with panned mono and a classic Blumlein
array, but the results show that a lot of the image posititoning
problems are not caused by the mic set-up but are actually inherent in
the two-loudspeaker playback arrangement.

It sounds interesting.

I used to have a lovely pink book about recording techniques which I
left at the theatre once and didn't find again.

This raises the old question of whether the recording engineer should
distort his recording in order to compensate for the defects of the
reproducing suystem.

I think in this case I ought to as the purpose of the recording is to be
listened to rather than to capture a perfect copy of the event.

I'm going to have to try to arrange a spot mic for the band, or take
some of their mix on the PA into the recording, though that adds some
monitoring black magic balancing it. I don't have a multitrack recorder
or outside broadcast lorry. The mics are almost over the stage, so the
singers are a lot closer to them than the musicians.

(I'm also running around like a headless chicken as we failed to secure
our followspot operator before last rehearsal so we have two operators
running between three things. A pain already in rehearsal as I've wanted
to change the band mix but been followspotting at the time. In production
starting tonight I'll run both lighting and sound during musical numbers
as both desks are in proximity. My lighting operator prefers manual mode
using group memories over sequence mode - more control, and maybe not
as boring as pressing "Next". Programming in a sequence could be risky
at this late stage - a bit like blind plotting which I've seen some
people do.)

- Richard

--
_/_/_/ _/_/_/ _/_/_/ Richard Corfield
_/ _/ _/ _/
_/_/ _/ _/ Time is a one way street,
_/ _/ _/_/ _/_/_/ except in the Twilight Zone

[Adrian Tuddenham]

Richard Corfield wrote:


(I'm also running around like a headless chicken as we failed to secure
our followspot operator before last rehearsal...

Brings back memories of operating follow-spots from the top of a swaying
scaffolding tower which was partly roped together from bits of two
different tower systems. I was sitting on a plank, directing one spot
with each hand and operating a pair of slate dimmers (screwed to a plank
a little further down) with my bare feet.

I wore a pair of gardening gloves because the lanterns were hot, so it
didn't matter that the 240v supply didn't have an earth connection.

Ahh... Happy days before risk-assessments were mandatory.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

[Richard Corfield]

On 2008-02-13, Adrian Tuddenham wrote:

Brings back memories of operating follow-spots from the top of a swaying
scaffolding tower which was partly roped together from bits of two
different tower systems. I was sitting on a plank, directing one spot
with each hand and operating a pair of slate dimmers (screwed to a plank
a little further down) with my bare feet.

I wore a pair of gardening gloves because the lanterns were hot, so it
didn't matter that the 240v supply didn't have an earth connection.

Ahh... Happy days before risk-assessments were mandatory.

Some of the rigging I've been doing this weekend wouldn't be allowed. We
did as much as possible with the bar lowered, but some things like
focusing and moving some lights around a little we did with the bar in
place. I think I should theoretically have had a harness, but instead
did the normal perch on top of step ladders with someone at the bottom
and hold onto the bar when I was high. A lot of the focusing had feet
below 2 meters so I think that is within the limit for working without
harness.

Back in my theatre days we had very big step ladders on stage, and very
big ordinary ladders up to the front of house bars which were secure
enough to rest the ladders against them. Our lighting director once had
the stage step ladders go over on him and was saved when the top tangled
in a safety chain. It shows how strong those safety chains are.

- Richard

--
_/_/_/ _/_/_/ _/_/_/ Richard Corfield
_/ _/ _/ _/
_/_/ _/ _/ Time is a one way street,
_/ _/ _/_/ _/_/_/ except in the Twilight Zone

[Rob Reedijk]

Mike Rivers wrote:
On Feb 11, 3:17 am, Richard Corfield
wrote:
If the image seems too wide, in that actors go towards the edges too
easily rather than stay in the middle, do I need to make the microphones
wider angled or narrower?

The simple answer is that there is only one "official" ORTF
configuration. Cardioid microphones at an included angle of 110
degrees, positioned so that at this angle, the capsules are 17
centimeters apart. Anything else and it is no longer ORTF. You are
supposed to place the mics so that you capture what you want.

I think if you are going to go hard-core official ORTF, you want to use
whatever types of mics they were using too! All these mic'ing techniques
are starting points, really. ORTF, XY, AB etc. Once you set them up,
it's worth adjusting them to the situation and mics. Change the angle,
the distance apart, the height, distance to source. Listen for how each
change effects the sound---in a number of ways.


Knowing that this is not always possible, you just listen while moving
the mics until you get the coverage and stereo field that you want. Be
sure to check the sound when left and right channels are combined to
mono to be sure that nothing important drops out.

Absolutely good advice.

Rob R.

[Mike Rivers]

On Feb 17, 11:55 am, Rob Reedijk wrote:
I think if you are going to go hard-core official ORTF, you want to use
whatever types of mics they were using too!

I suppose so, at least use true (textbook-pattern) cardioids, which I
think was what was used in the textbook configuration, Probably some
Schoepes or other.

ORTF is just one of the infinite number of "near coincident" stereo
mic setups, but it's one that has a definition. If I'm not mistaken,
"X-Y" is defined as two cardioids at 90 degrees, but with modern mics,
it's more often better implemented with two hypercardioids at 110
degrees.

All these mic'ing techniques are starting points, really.

Sure, but by adhering to a standard and making it work (by adjusting
non-specified parameters distance and height), you can more easily
repeat the technique should you need to do so.

[Scott Dorsey]

Mike Rivers wrote:
On Feb 17, 11:55 am, Rob Reedijk wrote:
I think if you are going to go hard-core official ORTF, you want to use
whatever types of mics they were using too!

I suppose so, at least use true (textbook-pattern) cardioids, which I
think was what was used in the textbook configuration, Probably some
Schoepes or other.

Doesn't matter, as long as it has a conventional medium cardioid pattern
and is flat off-axis sort-of.

One of the wonderful things about ORTF is that it does not rely on
aberrations of particular microphone designs, like the Decca Tree for
instance. It will work nicely with a wide variety of microphones.

ORTF is just one of the infinite number of "near coincident" stereo
mic setups, but it's one that has a definition.

There are several of these, including NOS, which have names. ORTF,
though, is a good starting point for most environments.

If I'm not mistaken,
"X-Y" is defined as two cardioids at 90 degrees, but with modern mics,
it's more often better implemented with two hypercardioids at 110
degrees.

It's not really X-Y any more, though, because it has a rear lobe. It's
something different. Yes, it's something that probably sounds better
because typical modern hypercardioids are better off-axis than typical
modern cardioids, but it's not the same.

All these mic'ing techniques are starting points, really.

Sure, but by adhering to a standard and making it work (by adjusting
non-specified parameters distance and height), you can more easily
repeat the technique should you need to do so.

Which is why there are calibrated stereo bars.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."