ORTF Microphone vertical angle

[Elk]

This may have already been discussed (although my searches revealed nothing) or may be a obvious/stupid question, but . . .

When recording an acoustic ensemble - such as a chamber orchestra - with mics directly five feet back from the conductor placed 12-15 feet high in an ORTF configuration should the mics be placed to face at a downward angle toward the musicians?

I am a beginner, using Shure KSM44 LDCs (in cardioid) or Beyer M 160s. I put the mics in ORTF, and then angle the adjustable arm at the top of my mic stand down a bit and try to aim for the mid-line of the ensemble.

I am getting good results, but its a bit tricky to get the mics setup. Plus I am always trying to learn better ways to record.

Thoughts and suggestions?

Ehrich

[boojum]

I aim the rig into the center of the group I am recording. I got it from John Eargle in one of his many excellent books on recording and recording technique. You want to be pointed at what you are recording.

[Dale]

you aim with your ears. the polar pattern can be used to final tune the placement to insure the optimum angle.

[rumleymusic]

I aim the rig into the center of the group I am recording.

That usually works for me, aiming for the first row of winds, it gives a better sense of clarity.

[DCtoDaylight]

This is all in line with my experience (limited by the standards of this group, but still...).

The thing is that you don't want any of the instruments too far off the centerline of the mics - frequency response often starts to get wonky out on the fringes of the pattern.

Also, make sure that you take into account additional instruments that may be brought out during the course of the performance - like, say, if a harpsichord or piano is used in one piece, and will be placed upstage or downstage of the main ensemble.

[Elk]

Thank you, everyone! Very helpful.

Originally Posted by Dale

the polar pattern can be used to final tune the placement to insure the optimum angle.

Do you mean that one can visualize the polar pattern and consider how it projects on to the group being recorded as a way to determine placement?

[Corran]

If the brass are a little too loud (in a wind ensemble) I'll aim the pair slightly down to emphasize the woodwinds. So yeah, to the center, but adjust if needed.

[Piedpiper]

Originally Posted by DCtoDaylight

This is all in line with my experience (limited by the standards of this group, but still...).

The thing is that you don't want any of the instruments too far off the centerline of the mics - frequency response often starts to get wonky out on the fringes of the pattern.

Also, make sure that you take into account additional instruments that may be brought out during the course of the performance - like, say, if a harpsichord or piano is used in one piece, and will be placed upstage or downstage of the main ensemble.

If you're looking for more detail and less room, you may want to move the mic in, being sure that the musicians are as close together as possible so as to insure that no one gets lost to the edges, either losing optimum frequency response or gaining exaggerated stereo spread.

You may also want to experiment with baffling between the mics with some foam so as to create a quasi dummy head to minimize phase cancellation, while being careful to avoid shadowing the mics too much.

[RobAnderson]

ORTF has an optimal pickup angle of 90-degrees.

Stand directly behind your mic stand. Look 45 degrees to your right and 45 degrees to your left. The ensemble should fit within this space. Otherwise move the mic stand back or decrease the spacing or angling between the mic's a little bit.

Else you will get exaggerated separation in the image.

[JonesH]

I feel there are two schools of audio engineers when it comes to on/off axis input to the mics. Some advocate the use of vertical tilting as a way to EQ the treble (even omnis will have different frequency response depending on angle) (for example mr Jean-Marie Geijsen of Polyhymnia talked a lot about this), while some people do not like off-axis colouration at all (take mr Jim Anderson for instance).

I find it a very effective tool for shaping your sound while not resorting to EQ:s.

[Piedpiper]

these parameters will be very mic dependent of course.

[Dale]

Originally Posted by RobAnderson

ORTF has an optimal pickup angle of 90-degrees.

Stand directly behind your mic stand. Look 45 degrees to your right and 45 degrees to your left. The ensemble should fit within this space. Otherwise move the mic stand back or decrease the spacing or angling between the mic's a little bit.

Else you will get exaggerated separation in the image.

ORTF is 110 degrees, 16.5 cm separation
NOS is 90 degree, 30 cm separation

JonesH has it right.
You do not visualize, you listen to the mics and adjust them to achieve the sound you want!

Piedpiper places this into the correct context!

[Piedpiper]

"aim with your ears" kinda wraps it up, doesn't it. although it helps to know what to listen for and why you might be hearing it.

[rumleymusic]

You do not visualize, you listen to the mics and adjust them to achieve the sound you want!

I don't know if I agree completely with that. Visualization is important, you just have to know what you should be looking for. Like I have reiterated several times on this forum, I have rarely gotten second chances at mic setup. Sometimes that option is taken out of the engineers hands (union crews, haning mics, time, rehearsal schedule etc.).

In those cases you have to make your best guess, and it is best you are familiar with the projection properties of the ensemble and what mic angle, height, and distance would be most appropriate for the sound you want.

[Piedpiper]

Originally Posted by rumleymusic

I don't know if I agree completely with that. Visualization is important, you just have to know what you should be looking for. Like I have reiterated several times on this forum, I have rarely gotten second chances at mic setup. Sometimes that option is taken out of the engineers hands (union crews, haning mics, time, rehearsal schedule etc.).

In those cases you have to make your best guess, and it is best you are familiar with the projection properties of the ensemble and what mic angle, height, and distance would be most appropriate for the sound you want.

good point. Though, it sure is nice to get a chance to adjust it at least once, if necessary, during the rehearsal/set up.

[Dale]

Originally Posted by rumleymusic

I don't know if I agree completely with that. Visualization is important, you just have to know what you should be looking for. Like I have reiterated several times on this forum, I have rarely gotten second chances at mic setup. Sometimes that option is taken out of the engineers hands (union crews, haning mics, time, rehearsal schedule etc.).

In those cases you have to make your best guess, and it is best you are familiar with the projection properties of the ensemble and what mic angle, height, and distance would be most appropriate for the sound you want.

visualization is useful only if you have done this many times before. You need to know how the mics you are using perform. the only way to know is to adjust then listen then adjust then listen ... after some time of doing this you may gain the insight for visualization!!!
and if this is a critical recording, nothing beats the tweak then when you use your highly trained ears and not your eyes!!!

[RobAnderson]

ORTF is 110 degrees, 16.5 cm separation
NOS is 90 degree, 30 cm separation

JonesH has it right.
You do not visualize, you listen to the mics and adjust them to achieve the sound you want!

Piedpiper places this into the correct context!

The angle between the mic's is 110. The optimal stereo recording angle is +/-45 degrees with regard to the center of the array.

Also true that your ears should be the final arbiter, but if you need a ballpark starting point, a visual reference is a good place to begin.

I also suggest that there are three variables that can be changed to achieve what your ears are after: source-to-mic distance, angle and spacing of the mic's.

Maybe exaggerated separation in the reproduced image is fine for what you are doing, but if not... ORTF is only one solution to the problem and this has an optimal stereo pickup angle of =<90 degrees. If this does not give you the results you want (in your highly-trained ears), then you need to modify the parameters until you get what you are after.

[rumleymusic]

Though, it sure is nice to get a chance to adjust it at least once, if necessary, during the rehearsal/set up.

Sometimes I find myself begging for that.

visualization is useful only if you have done this many times before. You need to know how the mics you are using perform.

You don't have to shout!!!

True, you have to be familiar with your equipment and have a good amount of experience to know what to aim for, I just don't want to rule out an important skill that needs to be developed. We cant just stand on a ladder and move the mics around during a rehearsal until we find the sweet spot.

[Dale]

Sorry, I ve been curt all day!!
I need to be more polite. the op was asking

I put the mics in ORTF, and then angle the adjustable arm at the top of my mic stand down a bit and try to aim for the mid-line of the ensemble.
I am getting good results, but its a bit tricky to get the mics setup.

My answer was wrong because I need to ask for more information. What are the specs on your mike stand/boom/stereo bar?? How high up are you going? ten feet?

[JEGG]

I point arrays according to:
1. What I want to exclude, ex.: ceiling, audience, etc.
2. What I want to include: example: wall, ceiling first reflections and such

I've never liked the sound of mic's pointed at floors, and often I don't like sources at 0 degrees. My default is 90 degrees (perpendicular to floor), then I raise and lower for ensemble balance and then point vertically for hall and ensemble "tuning."

[Elk]

Interesting (and helpful) discussion.

I am using a Shure S15A mic stand and putting the mics up about 13 feet (I never trust anything at full extension). Sabra-Som ST4 bar at the top. Very basic stuff. My hope is that the height will help bring the back row instruments up in balance.

I am usually recording chamber orchestras (although the next occassion will be Beethoven's Ninth, performed by a competent community orchestra and choir - this is going to be great fun.) I also record brass ensembles (from quintet to 13 piece brass choir).

As I typically would be happy to have a bit more of the winds in the orchestra recordings, the suggestion of pointing the mics at the first row of winds makes sense.

I generally get a pretty good soundstage with accurate positioning of the instruments, although the soundstage itself is a bit narrow (all is inside the speakers).

The mics feed an Avalon AD2022 and I record on a Tascam RA1000.

While I have the ability to add more mics and record multi-channel, I want to get a good understanding of properly setting up a primary pair of mics first. I am convinced more and/or better equipment does not make better recordings. That is, I need to concentrate on the warmware first.

I would like to acheive the best overall instrumental balance and timbre that I can, accompanied by a good sense of instrument positioning.

[DCtoDaylight]

Originally Posted by Elk

Interesting (and helpful) discussion.

I am using a Shure S15A mic stand and putting the mics up about 13 feet (I never trust anything at full extension). Sabra-Som ST4 bar at the top. Very basic stuff. My hope is that the height will help bring the back row instruments up in balance.

I am usually recording chamber orchestras (although the next occassion will be Beethoven's Ninth, performed by a competent community orchestra and choir - this is going to be great fun.) I also record brass ensembles (from quintet to 13 piece brass choir).

As I typically would be happy to have a bit more of the winds in the orchestra recordings, the suggestion of pointing the mics at the first row of winds makes sense.

I generally get a pretty good soundstage with accurate positioning of the instruments, although the soundstage itself is a bit narrow (all is inside the speakers).

The mics feed an Avalon AD2022 and I record on a Tascam RA1000.

While I have the ability to add more mics and record multi-channel, I want to get a good understanding of properly setting up a primary pair of mics first. I am convinced more and/or better equipment does not make better recordings. That is, I need to concentrate on the warmware first.

I would like to acheive the best overall instrumental balance and timbre that I can, accompanied by a good sense of instrument positioning.

Hey Elk - I'm in kind of a similar situation, and came to the exact same conclusion about the approach to take. It really seems like learning the stereo pair is the way to get the fundamentals down; then the extra mics can be the icing on the cake.

The discussions here have been a huge help, but the single most valuable thing for me so far has been the Michael Williams "Stereophonic Zoom" paper. You may have already given it a read, but if not, I think you'd find it really valuable. It touches on a lot of the issues that have been raised in this discussion!

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

Much success and fun to you!

[pkautzsch]

Originally Posted by RobAnderson

I also suggest that there are three variables that can be changed to achieve what your ears are after: source-to-mic distance, angle and spacing of the mic's.

Since source-to-mic distance (resulting in direct/reverb ratio and ensemble balance) is what makes most of the "overall sound" people can hear even if they're not listening in a controlled stereophonic triangle, this is what needs to be set first.
You want to put your mic where the direct/reverb ratio is right and the ensemble sounds balanced enough to be tweaked by angling.
Next step is wind/string balance (or choir/orchestra/soloist/whatever), done by angling the pair vertically, and maybe by adding spot or section mics.
Then you can adjust the recording angle (cf. Williams' Stereophonic Zoom - these must, of course, be guidelines, you need to listen) until the ensemble fills the space between your speakers as you like it. There's no rule saying the ensemble ALWAYS needs to be FULLY spread between speakers, though.

I can't quite believe that there is NO chance of listening before recording. Most ensembles will at least do a short rehearsal to get accustomed to the hall's acoustics. One should set up well before that, so the complete rehearsal can be used to tweak, even if it's just a couple of minutes.

[RobAnderson]

Since source-to-mic distance (resulting in direct/reverb ratio and ensemble balance) is what makes most of the "overall sound" people can hear even if they're not listening in a controlled stereophonic triangle, this is what needs to be set first.
You want to put your mic where the direct/reverb ratio is right and the ensemble sounds balanced enough to be tweaked by angling.
Next step is wind/string balance (or choir/orchestra/soloist/whatever), done by angling the pair vertically, and maybe by adding spot or section mics.
Then you can adjust the recording angle (cf. Williams' Stereophonic Zoom - these must, of course, be guidelines, you need to listen) until the ensemble fills the space between your speakers as you like it. There's no rule saying the ensemble ALWAYS needs to be FULLY spread between speakers, though.

Exactly what I am trying to say, but you do a much better job I think!

However, when I wrote my response my mind was more on those times where the ensemble is spread too wide or the array has to be too close for the pickup angle of the array.

[loujudson]

Originally Posted by pkautzsch

I can't quite believe that there is NO chance of listening before recording. Most ensembles will at least do a short rehearsal to get accustomed to the hall's acoustics. One should set up well before that, so the complete rehearsal can be used to tweak, even if it's just a couple of minutes.

I have had times when I was told to show up and it was fifteen minutes to curtain/downbeat (like showing up at 3 expectin a liesurely setup and rehearsal and finding out it starts at 3:30!). Others where the mic stand could not be on the floor, it had to be on the stage, One where the only choice for mic position was hanging through overhead light fixtures with 30 feet between them, hanging from the mic cable only, forcing me to use spaced imni in a hall that called for MS. Etc etc.

L

[Piedpiper]

Originally Posted by loujudson

I have had times when I was told to show up and it was fifteen minutes to curtain/downbeat (like showing up at 3 expectin a liesurely setup and rehearsal and finding out it starts at 3:30!). Others where the mic stand could not be on the floor, it had to be on the stage, One where the only choice for mic position was hanging through overhead light fixtures with 30 feet between them, hanging from the mic cable only, forcing me to use spaced imni in a hall that called for MS. Etc etc.

L

There's ideal and there's life. Accepting what is can make all the difference between everyone enjoying themselves and hell. I've certainly spent my time in the latter.

[loujudson]

Originally Posted by Piedpiper

There's ideal and there's life. Accepting what is can make all the difference between everyone enjoying themselves and hell. I've certainly spent my time in the latter.

I have a good time no matter what! These are the challenges we get thrown our way...

Oh, and the guy who makes his mics parrallel to the floor instead of pointing at the source? What are you reasons for that, seems it would be sub-optimal for almost anything except visual symmetry! It could be pointing at the mucisans , though the floor is under them why point it at the backstage wall? The logic escapes me.

L

[guosh]

i just remembered i did a recording of a wind ensemble earlier in the year with my mics in ortf, parallel to the floor

(why? i forgot to bring my mic clips so i ended up taping my mics down to my stereo bar)

it turned out to be usable, but not really to my liking. here's an unedited clip of how it went - rode nt5s -> oade T+ UA-5 -> microtrack 2. not the best chain in the world, but it was (thankfully) only a soundcheck for a competition later in the year!

p.s. its a really live hall!

[7rojo7]

Once you get your mics at the proper distance, then you have to pick the proper height to avoid early reflections (they still have an effect when off axis) from producing comb filtering, from there you would angle towards an even pickup of the whole ensemble and pray that they know how to play together.
When the critical distance dictates your distance from the ensemble and the array that you thought to have chosen instinctively will not work, change it to one that will and choose the mics you use according to that.
For me, most 2 mic main arrays don't cut it, I will use an OCT (rarely, string tri to camera) or something of my own (more commonly). For wide spreads (large ensemble), never (inverse square or proximity depending on the mics), you have to get too far away for any system to work with enough clarity. For deep ensembles (with choirs) there are different problems, for split ensembles (opera/operetta) even more.
Each has its own exigencies.
I find that there's nothing better than good preparation, knowing the venue and having the seating arrangement for the pieces. If you don't know it, go and check it out well before and get yourself prepared. After some experience you'll know how to approach each situation confidently.
Microphones are not ears connected to the brain, we only have to make it seem so.

In case anyone is wondering

SCHOEPS oct


I have good success with CCM21s and/or CCM5s in the nearest coincidence possible, even though this is not the recommendation
Has anyone here used line array techniques? Sounds interesting.

[rumleymusic]

There's ideal and there's life.

And life revolves around money and unions. There is never enough of the first and far too many of the second.