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What are the pros con between ORTF and XY?

  • How do you know which config to use?
  • Is one better for solo, quartet, choirs, orchestra?
  • How does crossing XY change the imaging vs the opposite in ORTF?
  • Does X have to be above Y (or vise versa) and why?
  • Do you use the same Cardioids for XY or ORTF or a?

Thanks!

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Comments

TheJackAttack Tue, 02/08/2011 - 22:51

ORTF gives you a "wider" spread to the sound. Austrian broadcasting has used this successfully for good reason and of course there is the NOS variant as well. The danger for these techniques if it can be called a danger, is in small ensembles one can lose a little of the center image.

XY is sort of the cookie cutter coincident stereo technique. XY is easily manipulated to the ensemble size and spread even though technically it's a 90 degree pattern. XY inevitably comes across more narrow in the aural field and as a result is slightly more mono compatible. Some folks use hypercardioids for ORTF (AT4053's come to mind) but most folks use quality normal cardioids for either pattern. The irony to me is that XY is half of a Blumlein array but I MUCH prefer Blumlein as a stereo technique. Either microphone (X or Y) can be on top. It goes both ways ^_^ Same with Blumlein. In MS I normally have the Mid cardioid on the bottom but it doesn't have to be. You aren't sent to the third circle of hell if you swap it out.

audiokid Tue, 02/08/2011 - 23:47

Thanks John, that's was very helpful. It makes more sense now that I understand the difference between the two in imaging. Even though they are both 90% the space apart in ORTF is enough to make it wider.

What does ORTF mean?

I'm guessing XY and flanks is more common together?
ORTF and a center is more common?

Am I getting it?

TheJackAttack Tue, 02/08/2011 - 23:55

With ORTF (120 degree spread) you don't use a center. XY (90 degrees same as Blumlein) is pretty well matched to pick up the center strongly. Flanks are used any time you think the wings have aural information that is perhaps too far forward of the mic pattern "center" to be picked up from either the X or the Y mic. A large ensemble is often better served by an ORTF array since it picks up a wider field of coverage. Small ensembles often "hide" in the center of an ORTF array so XY or Blumlein would be a better pattern.

Office de Radiodiffusion Télévision Française.

TheJackAttack Wed, 02/09/2011 - 00:12

Right. ORTF is not only at a 110-120 degree angle but the microphones themselves are 17cm apart. In XY the capsule are as close as you can get without touching at a 90 degree perpendicular placement. NOS (Belgium radio technique) is 90 degrees pattern but spread apart 30cm. The easiest way to set these patterns up quickly is to have some poster board with a pattern drawn out. Then the only thing you have to eyeball is the height and angle downward.

TheJackAttack Wed, 02/09/2011 - 00:21

In a Decca setup, the C mic is in front of the L-F. It looks like an upside down capital T. _|_ If your L-R pair are spread apart two meters the center should be closer to the stage by one meter. An easier way to think about it is go equal distant from your center point. Left one meter, right one meter, forward one meter. Sometimes the L-R is 1.5:1 ratio. I wouldn't worry about Decca. You're best bet for these choirs is either Blumlein or ORTF or A-B spaced pair. Decca is really for large instrumental ensembles and should be partially over the musicians themselves.

rojarosguitar Wed, 01/24/2018 - 06:28

I think main difference between ORTF and XY is that the second one is a 'coincident' technique and the first one a 'near coincident' one. With the coincident technique the diaphragms are in close proximity (as far as it is physically possible) and thus ther is (ideally) no time difference between the waves reaching both diaphragms (at least to high degree). XY registers the intensity (amplitude) difference via the directional characteristic of the employed cardiod mics. With ORTF there is both, time difference and intensity diffrerence through the 17cm spacing and 110° angling.
In my experience (and this is confirmed by many recording engineers) the ORTF recordings are more 'alive' and also wider. ORTF is not suitable for close field recording and can have a weak center image. Still I think ORTF is one of the best, most spaciously sounding systems if you have to work with just two cardioid microphones.

As was said, anything else that resembles ORTF but uses other mics is not ORTF in the sens of the definition, but could be called ORTFish and can be good.

rojarosguitar Mon, 01/29/2018 - 03:07

Yes, this kind of visual representation is very useful for estimating the stereo spread and the spatial representation of a group of musicians.
What is completely missing is the subjective hearing experience that is connected with the differences between intensity stereo vs. arrival-time stereo vs. a combination of both - which would correspond to XY (or Blumlein) vs. AB vs. near coincident like ORTF, NOS, Faulkner Array etc.

It is reported, and confirmed (for myself) by my own experience that XY are a bit dead, especially with ensembles; AB lack focus; and near conicident like ORTF have the best of both worlds: aliveness of arrival-time and focus of coincident techniques, to highest possible degree.

paulears Mon, 01/29/2018 - 14:37

One of my first recording jobs away was in the 70s, in a rather tatty studio near Manchester recording the Syd Lawrence Orchestra - a Glenn Miller inspired big band. The saxes were at one end, brass the other, and drums, guitar, piano and bass roughly in the middle. A/B technique for this new fangled stereo, so the familiar do-wop, do-wop brass/woodwind thing went across the entire room listening to the record. I think Philips were the record company for this album. I got the job for this one session from a friend of a friend of my dads, and I even had the record! My dad, of course was pleased that stereo meant you got two speakers, so one went in the dining room, and the other in the room next door.

I suspect ORTF or X/Y would have made my listening experience better. Looking back at the mix with modern hindsight, left-centre-right panning was extreme, but reverb was applied as a stereo return, so the left had the right musicians 100% missing apart from their reverb. It sounded really odd, but so did the Beatles back then, who had exactly the same problem. The BBC, of course with their classical stereo outputs were using much more sensible stereo techniques.

rojarosguitar Tue, 01/30/2018 - 08:23

Very cool post, Paul ... there were many odd sounding stereo records in the beginning time of stereo, probably because everybody was so fascinated with the pan pots... :sneaky:
Apart for the very obvious reason that AB, if done to extremely, gives an exaggerated stereo spread, it also doesn't give a very good localization or stable stereo image.
What I like about AB is its bandwidth frequency-wise. Maybe a tasteful combination of wide AB (like on outriggers) with ORTF would be the solution. I have to try one day.
Robert

Boswell Tue, 01/30/2018 - 10:33

rojarosguitar, post: 455531, member: 51093 wrote: Maybe a tasteful combination of wide AB (like on outriggers) with ORTF would be the solution. I have to try one day.

This used to be the style for large classical concerts, as well as using spot miking for solists.

I was amazed that nobody that I met who was involved in mixing the recorded microphone tracks delayed the outriggers with respect to the central pair. As soon as I started to do that on my mixes, I got a much more focussed sound. The idea seemed to spread quickly, maybe helped by the advent of digital processing (we are talking 1980s). I even got engineers coming to help in my sessions saying that they could show me a trick they had just learnt that would improve my mixes...

paulears Tue, 01/30/2018 - 12:14

Boswell's post made me think back to my examining music technology days - where because the spec permitted a maximum of four mics in the natural acoustic stereo recording - loads of people added rear mics and totally wrecked the stereo fields with the delay. Often in terrible reflective rooms too. I always left the stereoscope running to confirm what my ears told me and often you'd get to the part in the music where there was a singled out solo source - maybe somebody announcing - usually the conductor, or a piece that started with a single instrument then the rest joined in, and instead of a single line on the screen, there was a huge mess of lines and squiggles show all the phase errors. I'm not really certain if I can hear the difference between coincident placement and the time delays introduced with ORTF. I like to think I can hear A/B, but not the more subtle changes.

John Willett Fri, 08/31/2018 - 00:58

paulears, post: 455536, member: 47782 wrote: Boswell's post made me think back to my examining music technology days - where because the spec permitted a maximum of four mics in the natural acoustic stereo recording - loads of people added rear mics and totally wrecked the stereo fields with the delay. Often in terrible reflective rooms too. I always left the stereoscope running to confirm what my ears told me and often you'd get to the part in the music where there was a singled out solo source - maybe somebody announcing - usually the conductor, or a piece that started with a single instrument then the rest joined in, and instead of a single line on the screen, there was a huge mess of lines and squiggles show all the phase errors. I'm not really certain if I can hear the difference between coincident placement and the time delays introduced with ORTF. I like to think I can hear A/B, but not the more subtle changes.

This reminds me of the time, a few years back, where I went to Richard Huish College in Taunton and gave a talk (as a guest lecturer) on microphones (I have given this talk on quite a few occasions now).

I took along a bundle of my own microphones from several top manufacturers , so the students could actually see and handle the microphones.

In the evening the students did their "ambient recording" - so I gave them the choice of any of my microphones to do their recording with whatever mic. arrangement they choose.

It was an interesting day...

paulears Sat, 09/01/2018 - 04:42

Interesting as in slapping your head, I guess! When I was examining music technology, we had one entry and it sounded very, very strange. A Barbershop quartet. I couldn't pin down what was wrong with it, until I noticed a photo they had supplied. It clearly showed their M/S cluster, on a tall stand. Two AKG451 mics - plus a cardioid and fig-8 capsule, the really odd looking big lumpy thing. The fig-8 capsule was oriented up and down, not side to side. Nobody realised - checking the rest of the work from the same centre revealed they had all used it this way - so somebody set the thing up, and then they trotted everyone in one by one. They were supposed to make every candidate set up everything, but clearly left it set up after no.1 and the others just assumed it was right and used it, presumably without anyone actually listening. In the mark scheme, there were 5 marks available for stereo field. Clearly there was one - just a totally weird one, so 0 marks was out of the question, so they all got 1 mark. Out of the total, it hardly made a difference. That's my beef with the qualification system. Somebody with the mono button pressed could ruin a recording but hardly suffer if the rest was pretty good. Never ever had one student in college who could hear a compressor, or tell the difference between ORTF, X/Y, A/B or M/S by listening. Sad but true.

John Willett Sat, 09/01/2018 - 05:45

paulears, post: 458830, member: 47782 wrote: When I was examining music technology, we had one entry and it sounded very, very strange. A Barbershop quartet. I couldn't pin down what was wrong with it, until I noticed a photo they had supplied. It clearly showed their M/S cluster, on a tall stand. Two AKG451 mics - plus a cardioid and fig-8 capsule, the really odd looking big lumpy thing. The fig-8 capsule was oriented up and down, not side to side. Nobody realised - checking the rest of the work from the same centre revealed they had all used it this way - so somebody set the thing up, and then they trotted everyone in one by one. They were supposed to make every candidate set up everything, but clearly left it set up after no.1 and the others just assumed it was right and used it, presumably without anyone actually listening. In the mark scheme, there were 5 marks available for stereo field. Clearly there was one - just a totally weird one, so 0 marks was out of the question, so they all got 1 mark. Out of the total, it hardly made a difference. That's my beef with the qualification system. Somebody with the mono button pressed could ruin a recording but hardly suffer if the rest was pretty good. Never ever had one student in college who could hear a compressor, or tell the difference between ORTF, X/Y, A/B or M/S by listening. Sad but true.

Ouch !

At least in my case they *did* each set up the microphones themselves - they all had a free choice and I seem to remember that each student did something different.

But they did have good teachers there - the previous year they had a couple of students that went on to the Tonmeister course at Surry University.

paulears Sat, 09/01/2018 - 12:10

I'm still a member of the facebook group and the questions the new teachers ask! One is about the history of recording, and it's broadly split into the mono analogue days, the stereo days, the start of the digital days and current practice. She had none of the history and wanted to know where to find it on the internet - to teach to to the kids this month. On this forum and others, we're often arguing about tiny, tiny things we know are important - the new teachers are having to learn about the difference between analogue and digital, cardioids and other patterns, how any teacher can turn from audio newbie into an expert on such a strange subject in the weeks since their boss handed the the specification, I just don't know.

John Willett Sat, 09/01/2018 - 15:54

paulears, post: 458834, member: 47782 wrote: I'm still a member of the facebook group and the questions the new teachers ask! One is about the history of recording, and it's broadly split into the mono analogue days, the stereo days, the start of the digital days and current practice. She had none of the history and wanted to know where to find it on the internet - to teach to to the kids this month. On this forum and others, we're often arguing about tiny, tiny things we know are important - the new teachers are having to learn about the difference between analogue and digital, cardioids and other patterns, how any teacher can turn from audio newbie into an expert on such a strange subject in the weeks since their boss handed the the specification, I just don't know.

That’s frightening - that teachers know so little about the subject they are supposed to teach.

bouldersound Sat, 09/01/2018 - 15:57

John Willett, post: 458835, member: 47971 wrote: That’s frightening - that teachers know so little about the subject they are supposed to teach.

I was working with an engineer who taught recording at a nearby university. This person knew all sorts of stuff about computers but ran digital levels into clipping all the time.

paulears Sun, 09/02/2018 - 00:57

If you are a NQT, then you teach whatever is required. Maybe your own 'specialist' subject - let's say, computers - has low numbers. It won't run, so they think maybe A Lev el Music Technology could be more attractive, as numbers=funding. They see the word computer, and note in their CV that they played the cello when they were 14, achieving grade 7. Grade 7 = a formal qualification on the Government's framework, so music + technology means they are not just the teacher, but the subject specialist. They go on a one or two day exam board training course in the subject, and that is that! They have the specification, the attendance on the course, and they are a legitimate teacher of the subject. My college lecturing finished in 2004, I continued as a Principle Examiner for 8 more years then had enough. I also discovered this gave me an equivalent qualification in teaching in schools as a supply teacher - short-cutting the quals a new teacher had. My own subjects, music and performing arts were terrible to teach the standards so low so I volunteered to teach ANYTHING, because real teachers don't do this. I taught cookery (with a new PC title), science was fine, and one day spent the entire day teaching French to year 10. The Head of French was interviewing for a teacher and walked through my classroom continually. At the end of the day I asked if she found anyone? No - they were all terrible - she then asked if I wanted the job as I got on well with the kids. I then revealed that my last French was when I was at school in 1974! She was confused. I heard you all day, you answered all their questions ...... I pointed out the wall was covered with posters Je suit, tu est, etc etc - I heard you answer questions??? I told her that when a girl asked me what one phrase was, I had no idea, so told her I just needed to talk to another who had her hand up first and on my way, looked over their shoulders, read their work and then went back and said "Grandfather's Beard - Candy Floss" - BUT - you have the accent???? I like 'All, 'Allo.

The worst examiners I ever trained were a bunch got via an advert in Sound on Sound Magazine. They didn't last long. Played them a bit of student work and asked them for a gut reaction. A or E? They all picked E. It was an A. They had so much trouble accepting terrible recordings as mark earners simply because there was no noise or distortion, it had stereo field, the balance and blend was good (difficult to get wrong with perhaps 3 instruments) and criteria of this kind, looked at in isolation. As soon as you hear it, you know it was a poor recording, probably a random event with no real thought processes - but it scores high. GCSE music is awful, A Level Music Technology is far, far too wide for an A Level to cover, and A Level traditional Music is probably still OK because it's theory and history, and needs good ears. Without them, they do terribly. Musicians do well. A Bach choral hasn't;t changed much. Music Technology started with 4 tracks on a cassette portastudio, now everyone has cracked Cubase and Protools at home. Schools have terrible listening rooms, and very poor studios, with ill maintained equipment. Generally. A few exceptions of course with excellent facilities and cracking staff who know their subject inside out. These are the minority. For some teachers, a finalised CD was hard going!

John Willett Mon, 09/03/2018 - 07:18

paulears, post: 458837, member: 47782 wrote: If you are a NQT, then you teach whatever is required. Maybe your own 'specialist' subject - let's say, computers - has low numbers. It won't run, so they think maybe A Lev el Music Technology could be more attractive, as numbers=funding. They see the word computer, and note in their CV that they played the cello when they were 14, achieving grade 7. Grade 7 = a formal qualification on the Government's framework, so music + technology means they are not just the teacher, but the subject specialist. They go on a one or two day exam board training course in the subject, and that is that! They have the specification, the attendance on the course, and they are a legitimate teacher of the subject. My college lecturing finished in 2004, I continued as a Principle Examiner for 8 more years then had enough. I also discovered this gave me an equivalent qualification in teaching in schools as a supply teacher - short-cutting the quals a new teacher had. My own subjects, music and performing arts were terrible to teach the standards so low so I volunteered to teach ANYTHING, because real teachers don't do this. I taught cookery (with a new PC title), science was fine, and one day spent the entire day teaching French to year 10. The Head of French was interviewing for a teacher and walked through my classroom continually. At the end of the day I asked if she found anyone? No - they were all terrible - she then asked if I wanted the job as I got on well with the kids. I then revealed that my last French was when I was at school in 1974! She was confused. I heard you all day, you answered all their questions ...... I pointed out the wall was covered with posters Je suit, tu est, etc etc - I heard you answer questions??? I told her that when a girl asked me what one phrase was, I had no idea, so told her I just needed to talk to another who had her hand up first and on my way, looked over their shoulders, read their work and then went back and said "Grandfather's Beard - Candy Floss" - BUT - you have the accent???? I like 'All, 'Allo.

The worst examiners I ever trained were a bunch got via an advert in Sound on Sound Magazine. They didn't last long. Played them a bit of student work and asked them for a gut reaction. A or E? They all picked E. It was an A. They had so much trouble accepting terrible recordings as mark earners simply because there was no noise or distortion, it had stereo field, the balance and blend was good (difficult to get wrong with perhaps 3 instruments) and criteria of this kind, looked at in isolation. As soon as you hear it, you know it was a poor recording, probably a random event with no real thought processes - but it scores high. GCSE music is awful, A Level Music Technology is far, far too wide for an A Level to cover, and A Level traditional Music is probably still OK because it's theory and history, and needs good ears. Without them, they do terribly. Musicians do well. A Bach choral hasn't;t changed much. Music Technology started with 4 tracks on a cassette portastudio, now everyone has cracked Cubase and Protools at home. Schools have terrible listening rooms, and very poor studios, with ill maintained equipment. Generally. A few exceptions of course with excellent facilities and cracking staff who know their subject inside out. These are the minority. For some teachers, a finalised CD was hard going!

OMG - I am shocked !!!

My wife is a teacher - she teaches languages (she is fluent in Slovak, Czech, French, Italian and Russian - and her English is pretty good) - but she teaches mostly Ambassadors and Diplomats and some at University level.