ORTF advice needed

[Lloyd Frank]

Hello, group.

OK, I'm obviously an idiot, since I can't figure out the solution
to this one by myself. I'm not a professional recordist, nor do I play
one on TV. But my wife and I caught the recording bug big time six years
ago, and it's been full steam ahead ever since. She's a pianist, and I
am a violist. We record ourselves, small chamber ensembles, and, most
recently, the community orchestra I play in. Our most recent purchase
was a pair of Neumann KM184s. My wife is in heaven: "This is the sound
of my piano." I have been trying to record using the 184s in ORTF
configuration, and here is my problem:

I know the requirements for proper ORTF state the the center of
the mic capsules must be 17 cm apart, and the angle between the capsules
ust be 110 degrees. My problem is that the big XLR connectors butt up
against one another when I try to put the mics into the proper
configuration. If I let one XLR connector to slide over the other, one
of the mics is then pointing up, and the other is pointing down. I have
tried two different stereo bars. Same problem. It seems I can either
have the angle between the mics correct at 110 degrees, or the distance
between the capsules correct at 17 cm, but not both. I've also tried
different mic mounts--the ones that came with the 184s and a pair of AT
shockmounts. Obviously, I'm doing something wrong, but I can't figure
out what.

Which is why I have come to unburden myself here. I would
appreciate any advice you have. I suppose I am being overly fussy, but
it seems to me I ought to be able to put the microphones into their
correct positions. Thanks for listening.

Regards,

Lloyd

--
Lloyd Joseph Frank
Department of Music
University of Pennsylvania

[hank alrich]

Lloyd Frank wrote:

> My problem is that the big XLR connectors butt up
> against one another when I try to put the mics into the proper
> configuration. If I let one XLR connector to slide over the other, one
> of the mics is then pointing up, and the other is pointing down. I have
> tried two different stereo bars. Same problem. It seems I can either
> have the angle between the mics correct at 110 degrees, or the distance
> between the capsules correct at 17 cm, but not both.

1. You could make mic cables with right angle XLRs.

2. See the Shure A27M stereo mounting device, with which you may achieve
precise ORTF angle and separation, with the variance being completely in
the vertical plane, yet with both mics still in the same horizontal
plane.

--
ha

[Henrik Kristensen]

On Sat, 17 Jul 2004 17:13:33 +0000 (UTC),
(Lloyd Frank) wrote:
[...]
> I know the requirements for proper ORTF state the the center of
>the mic capsules must be 17 cm apart, and the angle between the capsules
>ust be 110 degrees. My problem is that the big XLR connectors butt up
>against one another when I try to put the mics into the proper
>configuration. If I let one XLR connector to slide over the other, one
>of the mics is then pointing up, and the other is pointing down. I have
>tried two different stereo bars. Same problem. It seems I can either
>have the angle between the mics correct at 110 degrees, or the distance
>between the capsules correct at 17 cm, but not both. I've also tried
>different mic mounts--the ones that came with the 184s and a pair of AT
>shockmounts. Obviously, I'm doing something wrong, but I can't figure
>out what.

I have 3 suggestions:

1. Have you tried using angled XLR connectors? -Maybe they will fit
between the mics.

2. Elevate one of the mics 2 cm by using some kind of spacer between
the bar and the mic clip. For example made up using a couple of thread
adapters (e.g. going to 1/2" and back). Such a small diff in height
should not have an impact on the stereo image.

3. Slide the two mics over each other like you have tried. And then
compensate (get the mics level) by tilting the bar a bit (if you mic
stand allows this). This will also result in one mic being slightly
higher than the other.

[...]

--
Henrik

[Lloyd Frank]

hank alrich ) wrote:

: 2. See the Shure A27M stereo mounting device, with which you may achieve
: precise ORTF angle and separation, with the variance being completely in
: the vertical plane, yet with both mics still in the same horizontal
: plane.


My thanks for such a prompt reply. I went to the Shure website
and looked at the user guide to the A27M mount. Their "Figure 2" shows a
pair of mics deployed in ORTF configuration. As you said, the mics would
be properly positioned in the horizontal plane, but there would be some
distance between them in the vertical plane. Do you have an opinion as
to what impact, if any, this vertical "displacement" would have when
recording a source, say, like an orchestra? Many thanks.

Regards,

Lloyd

--
Lloyd Joseph Frank
Department of Music
University of Pennsylvania

[Lloyd Frank]

Henrik Kristensen ) wrote:
: I have 3 suggestions:

: 1. Have you tried using angled XLR connectors? -Maybe they will fit
: between the mics.

: 2. Elevate one of the mics 2 cm by using some kind of spacer between
: the bar and the mic clip. For example made up using a couple of thread
: adapters (e.g. going to 1/2" and back). Such a small diff in height
: should not have an impact on the stereo image.

: 3. Slide the two mics over each other like you have tried. And then
: compensate (get the mics level) by tilting the bar a bit (if you mic
: stand allows this). This will also result in one mic being slightly
: higher than the other.

Henrik,

My thanks for your reply. I will try your second and third
suggestions.

Regards,

Lloyd

--
Lloyd Joseph Frank
Department of Music
University of Pennsylvania

[Eberhard Sengpiel]

Lloyd Frank > wrote
> Henrik Kristensen ) wrote:
> My thanks for your reply. I will try your second and third
> suggestions.


Hello Lloyd,

an other proposal. Go as close at you can get with your
XLR plugs. Than you will have a bit more distance
between the microphones. That is no problem. You can
compensate this by a narrower angle than 110°.
Neither 17 cm nor the 110° is said to be ultimate.
That may change also a bit the recording angle.
See here some different systems with the angles:
http://www.sengpielaudio.com/VergleichAequivalenzMikrofonSyst.pdf

Cheers

Eberhard Sengpiel
German forum for microphone recordings
and sound studio techniques
http://www.sengpielaudio.com

[Harry Lavo]

"Lloyd Frank" > wrote in message
...
> Hello, group.
>
> OK, I'm obviously an idiot, since I can't figure out the solution
> to this one by myself. I'm not a professional recordist, nor do I play
> one on TV. But my wife and I caught the recording bug big time six years
> ago, and it's been full steam ahead ever since. She's a pianist, and I
> am a violist. We record ourselves, small chamber ensembles, and, most
> recently, the community orchestra I play in. Our most recent purchase
> was a pair of Neumann KM184s. My wife is in heaven: "This is the sound
> of my piano." I have been trying to record using the 184s in ORTF
> configuration, and here is my problem:
>
> I know the requirements for proper ORTF state the the center of
> the mic capsules must be 17 cm apart, and the angle between the capsules
> ust be 110 degrees. My problem is that the big XLR connectors butt up
> against one another when I try to put the mics into the proper
> configuration. If I let one XLR connector to slide over the other, one
> of the mics is then pointing up, and the other is pointing down. I have
> tried two different stereo bars. Same problem. It seems I can either
> have the angle between the mics correct at 110 degrees, or the distance
> between the capsules correct at 17 cm, but not both. I've also tried
> different mic mounts--the ones that came with the 184s and a pair of AT
> shockmounts. Obviously, I'm doing something wrong, but I can't figure
> out what.
>
> Which is why I have come to unburden myself here. I would
> appreciate any advice you have. I suppose I am being overly fussy, but
> it seems to me I ought to be able to put the microphones into their
> correct positions. Thanks for listening.

Common problem with a stereo bar. Frankly, it is more important to maintain
the 17cm 110 deg spacing than vertical "tilt". If you don't have spacers,
as other suggested, simply tilt one up and one down slightly. The angle is
rarely more than 5 deg each, and that angle will make little/no difference
in pickup. If you are recording strings, I'd have one as close as possible
pointing to the first violin, but even that is optional. Experiement a
bit...I've had to do this many dozens of times, and never failed to capture
a good sound.

[Bob Cain]

Lloyd Frank wrote:


> My thanks for such a prompt reply. I went to the Shure website
> and looked at the user guide to the A27M mount. Their "Figure 2" shows a
> pair of mics deployed in ORTF configuration. As you said, the mics would
> be properly positioned in the horizontal plane, but there would be some
> distance between them in the vertical plane. Do you have an opinion as
> to what impact, if any, this vertical "displacement" would have when
> recording a source, say, like an orchestra? Many thanks.

Very little, if any, either in theory or in my experience.


Bob
--

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

A. Einstein

[JoVee]

undoubtedly you've already been told that there are A3F mic connectors that
have a right-angle bend in them that should do you fine. Buy a pair of 20'
or so cables and you're there! If CONQUEST is still managing to stay in
business, they have very nice ones in a plethora of colors.
I hate to say the following but get the NEUTRIK right-angle connectors on
teh cables as, for some god-forsaken incomprehsnsible reason, SWITCHCRAFT
stopped putting any sort of real strain relief in theirs...



Lloyd Frank at wrote on 7/17/04 1:13 PM:
> I know the requirements for proper ORTF state the the center of
> the mic capsules must be 17 cm apart, and the angle between the capsules
> ust be 110 degrees. My problem is that the big XLR connectors butt up
> against one another when I try to put the mics into the proper
> configuration.

> Lloyd
>
> --
> Lloyd Joseph Frank
> Department of Music
> University of Pennsylvania
>

--
John I-22
(that's 'I' for Initial...)
Recognising what's NOT worth your time, THAT'S the key.
--

[Mike Rivers]

In article > writes:

> OK, I'm obviously an idiot, since I can't figure out the solution
> to this one by myself.

> I know the requirements for proper ORTF state the the center of
> the mic capsules must be 17 cm apart, and the angle between the capsules
> ust be 110 degrees. My problem is that the big XLR connectors butt up
> against one another when I try to put the mics into the proper
> configuration.

You know, I had a suspicion that's what you were going to ask.

> If I let one XLR connector to slide over the other, one
> of the mics is then pointing up, and the other is pointing down.

That really isn't all that much of a problem. They only diverge by
about ten degrees or so. You can always skew the stereo bar a bit. You
can also ofset the mics vertically so the connectors clear. There are
some stereo bars that are built to do that, either with a "step" in
the horizontal bar or with one of the mounting studs longer than the
other.

But my solution is to use right-angle XLR connectors for the mics.
The cable then points downward, and the lump behind the microphone is
short enough so that you can position the mics the way you want. Go to
http://www.switchcraft.com/ and search for R3F.


--
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 here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> My thanks for such a prompt reply. I went to the Shure website
> and looked at the user guide to the A27M mount.

Gee, why didn't I think of that? I own one myself, but I rarely use
ORTF.

> the mics would
> be properly positioned in the horizontal plane, but there would be some
> distance between them in the vertical plane. Do you have an opinion as
> to what impact, if any, this vertical "displacement" would have when
> recording a source, say, like an orchestra?

None. Don't sweat it.


--
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 here: double-m-eleven-double-zero at yahoo

[Scott Dorsey]

Lloyd Frank > wrote:
>
> My thanks for such a prompt reply. I went to the Shure website
>and looked at the user guide to the A27M mount. Their "Figure 2" shows a
>pair of mics deployed in ORTF configuration. As you said, the mics would
>be properly positioned in the horizontal plane, but there would be some
>distance between them in the vertical plane. Do you have an opinion as
>to what impact, if any, this vertical "displacement" would have when
>recording a source, say, like an orchestra? Many thanks.

It should be inaudible except for sounds coming very far off of the plane
of the microphones, like from the ceiling. And frankly you don't care
all that much about accurate imaging of ceiling reflections.

Having everything on one plane is a good idea, but not utterly critical.
--scott

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

[ScotFraser]

Make yourself a little extender with some mike stand thread adaptors. Get a US
to European thread adaptor, & a European to US thread adaptor. Screw them
together to provide female threads on one end & male threads on the other & you
have now a mike mount extender that is about the length of the diameter of your
KM184s, allowing you to position one slightly higher than the other, so the
cables don't interfere with one another. Problem solved.




Scott Fraser

[Paul Stamler]

"Henrik Kristensen" > wrote in message
...

> 1. Have you tried using angled XLR connectors? -Maybe they will fit
> between the mics.
>
> 2. Elevate one of the mics 2 cm by using some kind of spacer between
> the bar and the mic clip. For example made up using a couple of thread
> adapters (e.g. going to 1/2" and back). Such a small diff in height
> should not have an impact on the stereo image.
>
> 3. Slide the two mics over each other like you have tried. And then
> compensate (get the mics level) by tilting the bar a bit (if you mic
> stand allows this). This will also result in one mic being slightly
> higher than the other.

I've been doing (3) for years. It works fine. For all that time, I've been
promising myself a set of right-angled XLR cables, but somehow I've never
gotten around to it.

Peace,
Paul

[normanstrong]

> Lloyd Frank wrote:
>
> > My problem is that the big XLR connectors butt up
> > against one another when I try to put the mics into the proper
> > configuration. If I let one XLR connector to slide over the
other, one
> > of the mics is then pointing up, and the other is pointing down.
I have
> > tried two different stereo bars. Same problem. It seems I can
either
> > have the angle between the mics correct at 110 degrees, or the
distance
> > between the capsules correct at 17 cm, but not both.

Add a 2" extension to one mike mount. This allows the mikes to stay
in the same plane, but slightly offset. You can do it the way I do
it. Mount one mike upside down; this allows the same effect.

[Lloyd Frank]

Paul Stamler ) wrote:

: I've been doing (3) for years. It works fine. For all that time, I've been
: promising myself a set of right-angled XLR cables, but somehow I've never
: gotten around to it.


Thanks to everyone for the boatload of great advice and
suggestions. I have a lot more to work with now than at this time
yesterday, without a doubt! Mostly, I'm glad to learn that I wasn't
completely crazy, and that it can be difficult, sometimes, to wrestle the
mics into position. (It would be embarrassing to describe the hours it
took before I created a reasonable looking Blumlein configuration, not to
mention M/S!). Anyway, I just wanted to say Thanks!

Regards,

Lloyd


--
Lloyd Joseph Frank
Department of Music
University of Pennsylvania

[JoVee]

Lloyd Frank at wrote on 7/18/04 12:55 PM:

> Thanks ... Mostly, I'm glad to learn that I wasn't
> completely crazy, and that it can be difficult, sometimes, to wrestle the
> mics into position. (It would be embarrassing to describe the hours it
> took before I created a reasonable looking Blumlein configuration, not to
> mention M/S!).

You're hardly stupid/crazy/inept or any other insulting adjective, merely
one more of us who wrestle with this sort of thing regularly. I spent DAYS
first time working out a way to mount a pair of AT4050 mics in swivel
suspension mounts into a swing-arm stereo-bar to both hang safely and
solidly on an 80' line from the cieling of a concert hall, and variously
get an XY or Blum or ORTF or MS positioning that would stay put... and every
time it goes up it's ALWAYS a worry that it WILL indeed hang right and stay
put.


--
John I-22
(that's 'I' for Initial...)
Recognising what's NOT worth your time, THAT'S the key.
--

[Frank Vuotto]

Here's a diy bar that I've been using for 20 years.

http://www7.taosnet.com/f10/stereobar.html

Frank /~ http://newmex.com/f10
@/