Topic: quick question for anyone running ca-14 cards - re placement/spread

[lt-cartman]

Hi All.

Toolman here

This question is for anyone taping bands in small venues with church audio ca-14 cards (or similar cards)

How far apart do you place your mics and at what angle to each other?
I read on another post that one of the posters has a starting position of 14" apart and an angle of 55 degree

I am expecting delivery of a ca9100 preamp and ca-14 cards along with a sony pcm-m10 in a few weeks and I will be making a custom stand / spreader bar for them so info on placement and angle would be benifficial to say the least

Now I know that every venue \ pa setup is different but a general starting point along with a room size comparison would help me figure out dimensions needed and a starting position for say a sub 200 people venue compared to the starting point of a 5,000 seater hall.

Thanks all in advance for your replies.

Toolman
 

[Craig T]

DIN (20cm @ 90*)
ORTF (17cm @ 110*)
NOS (30cm @ 90*)

55* is too narrow, IMO.

[lt-cartman]

Hi Craig thanks for your reply.

anyone else have info?

Toolman

[Belexes]

I think most people run cards here DIN but if the room has challenging acoustics, then ORTF is nice.

[lt-cartman]

Hi Belexes thanks for that info very helpful - any others care to chime in.

Toolman

[F.O.Bean]

I think most people run cards here DIN but if the room has challenging acoustics, then ORTF is nice.

See, I disagree. ORTF would best be run in the "sweep spot" since its a wider pattern. For challenging rooms I would use DIN or a narrower angle to give yuou a tighter sound

[newplanet7]

I have done all the standard  configurations listed above and there really is no one pattern fits all
type of configuration. You have to know what you are listening for and have a good
visual understanding of the venue when setting up.

My general rule of thumb is wider up front, narrower the further you are away from the source.
So after you try out some of the standards and understand what best fits where, Start experimenting
because IMO that is the fun part. Run one configuration for one set and another config for the next set.

Try new things like wider cap spacing and decreased angle variations.
With cards/subcards you have a ton of different set-ups your possibilities are unlimited.

[lt-cartman]

HI New Planet.

Thanks for the input its very appreciated, the tip about wide up front and narrower the further you are away from the source. is very appreciated. You see possibly the first time i will get to use these and the sony pcm-m10 will be videoing the band i talked about (but these times i video them in what ever venue they are in it is very important that i nail the sound and video (no pressure lol) so tips like the one you gave me are well appreciated.

Toolman.

[YYzepp]

DIN (20cm @ 90*)
ORTF (17cm @ 110*)
NOS (30cm @ 90*)

55* is too narrow, IMO.

I searched for but found only abbreviations so for us newbies can you explain what these abbreviations actually mean? Thanks.
--
Tony

Merry Christmas and Happy Holidays!

[bryonsos]

DIN (20cm @ 90*)
ORTF (17cm @ 110*)
NOS (30cm @ 90*)

55* is too narrow, IMO.

I searched for but found only abbreviations so for us newbies can you explain what these abbreviations actually mean? Thanks.
--
Tony

Merry Christmas and Happy Holidays!

I find this paper to be helpful:

http://www.wesdooley.com/pdf/BASIC_MIC_PERSPECTIVES_REVIEW_(JAES).pdf

[achalsey]

I searched for but found only abbreviations so for us newbies can you explain what these abbreviations actually mean? Thanks.
--
Tony

Merry Christmas and Happy Holidays!

The full designations aren't really important for recording, the abbreviations are just short for the national broadcasting agencies that made them famous.

ORTF: Office de Radiodiffusion Télévision Française
NOS: Nederlandse Omroep Stichting
DIN:  Deutsches Institut für Normung

[flipp]

DIN (20cm @ 90*)
ORTF (17cm @ 110*)
NOS (30cm @ 90*)

55* is too narrow, IMO.

I searched for but found only abbreviations so for us newbies can you explain what these abbreviations actually mean? Thanks.
--
Tony

Merry Christmas and Happy Holidays!

I find this paper to be helpful:

http://www.wesdooley.com/pdf/BASIC_MIC_PERSPECTIVES_REVIEW_(JAES).pdf

another good source though it is now offline but is preserved in the internet archive's wayback machine is the following page from http://www.recordinglair.com/record/location/micplace.htm

Microphone Placement

The best way to record most classical ensembles is with a matched pair of high quality condenser microphones used in a stereo recording technique. Below are some stereo microphone techniques, followed by how we would record some common ensembles.

ORTF

The French Radio Organization developed this technique. A high quality, matched pair of cardioid condenser microphones are placed 17 cm apart at an angle of 110 degrees. The distance from the ensemble will determine the amount of room reverberation - further away from the ensemble will have more reverb and closer placement will have less room sound. A good starting placement would be approximately 7 feet away and 9 feet up.

NOS

This technique was developed by Dutch Broadcasting (Nederlandsche Omroep Stichting).The NOS is similar to ORTF, however the cardioid microphones are 30cm apart and at an angle of 90 degrees.    

RAI

(Italian Broadcasting Corporation) The RAI technique is similar to ORTF, however the cardioid microphones are 21cm apart and at an angle of 100 degrees.     

DIN

(Proposed for standard in Germany) The DIN technique is similar to ORTF, however the cardioid microphones are 20cm apart and at an angle of 90 degrees.    

Olson

The Olson technique is similar to ORTF, however the cardioid microphones are 20cm apart and at an angle of 135 degrees.
    
XY

Two cardioid microphones are placed at 90 degrees and the capsules are positioned as close as possible.     

MS Technique

This technique uses two microphones placed close to each other. One microphone has a cardioid pick up pattern and the other with a figure 8 pick up pattern. The cardioid microphone faces the ensemble (this microphone picks up the Middle). The figure 8 microphone is at a right angle to the cardioid (this microphone picks up the Sides). The cardioid microphone is panned to center. The figure 8 microphone is split into two channels and panned hard left and right. The phase of the left remains normal while the right is reversed. By increasing the level of the figure 8 microphone the room acoustics (reverb) will increase. The MS stereo technique is excellent for mono compatibility.    

Spaced Omnis

This technique uses two (or three for large ensembles) omni-directional microphones evenly placed in front of an ensemble. This technique can easily produce phasing problems. A 3:1 rule should be utilized. The 3 to 1 rule states that for every 1 unit of distance from the sound to the microphone should be 3 units of distance between microphones. (Example: microphones are 5 feet in front of the ensemble - the distance between the two microphones cannot be less than 15 feet - 7.5 feet each from the center line.) The microphones in spaced omni should typically be 2 to 10 feet from the center line.
    
Blumlein

Blumlein uses two figure 8 microphones at 90 degrees to each other. The capsules are positioned as close as possible to each other (coincident). Because the microphones pick up in front and back both the ensemble and the room sound is represented well.    

Omni Out-Riggers

For large ensembles, the techniques mentioned above can be enhanced by adding a pair of omni out riggers. Recording a very large ensemble one of the techniques above may be enhanced by adding omni out-riggers. The outriggers should be placed at the same distance on each side of the center stereo microphone array.

[newplanet7]

And to go along with the already great answers, to help with visualization
DPA has a great page Here:
http://www.dpamicrophones.com/en/Mic-University/StereoTechniques.aspx

[hoppedup]

Also, If you find yourself in a situation where the standard configurations don't seem practical or didn't sound that good on a previous tape in the same room, don't be afraid to use PAS, or Point At Stacks, which is just what it sounds like. I usually run DIN but I will adjust the angle a bit sometimes depending on the layout/sound of a room.
 

[YYzepp]

Thanks guys, especially Flipp, for all the great info. Much appreciated! More to learn, more to learn..... so little to do and so much time! ...strike that, reverse it!