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Author Topic: The glorious Blumlein  (Read 28602 times)

otek

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The glorious Blumlein
« on: June 12, 2004, 12:31:53 AM »

I have used the Blumlein configuration quite extensively for ambience miking, and I have usually been very pleased with the sound. It seems to give a very exact, three-dimensional representation of most ensembles, provided the room is good, and provided I keep plenty of distance to the walls in all directions (I am not sure if this is actually necessary, it's just the way it's sounded to me every time).

Now, I mostly go entirely by subjective opinion. I listen, and if I like it, I use it. Which has been the case with this technique.

But I would definitely be interested in hearing what the theoretical background to the Blumlein configuration is. I don't know how to explain this in correct technical terms, so bear with me here, but I have imagined that its precise nature and ability to pinpoint instruments in the stereo field comes from the fact that the pickup pattern of each figure-eight shares very little "common ground" with the other, and therefore the stereo image becomes clearer.

Am I full of crap here? Can someone explain it to me in a better way?
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David Satz

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Re: The glorious Blumlein
« Reply #1 on: June 12, 2004, 01:04:48 PM »

Hello, otek--I think that your intuition is largely correct.  For direct sound, an appropriately placed Blumlein pair offers the most accurate and the smoothest possible distribution of apparent sound sources across the stereo "basis width" (lateral stereo image). No other form of coincident pair can offer equally precise localization, and certainly a spaced pair of microphones cannot do so.

What I mean by "precise" or "accurate" here has a specific technical meaning:  The angle from center (between the two extremes of the entire ensemble that you're recording) at which each discrete sound source occurred in the hall can be reproduced so that to a centrally placed listener, it will seem to occur at essentially the same angle between the two loudspeakers, if your Blumlein microphone setup was placed optimally for that purpose.  The sounds will not bunch up toward the middle as they do with X/Y cardioids, nor will they seem to be only in and around the loudspeakers ("hole in the middle" effect) as can often occur with poorly spaced omnis.

When you speak about the shared "common ground" between two coincident directional microphones, I agree that that's a big part of what determines imaging. Of course in the center of a stereo image there has to be "common ground"--you want the left and right channels to pick up the central sound source(s) in equal amounts and with the same arrival time.  But you don't want the centrally-located sources to appear more prominent or less prominent than their actual contribution was to the whole.  And when you then consider the discrete sound sources that are off-center in one direction or the other, there is a certain proportion by which the increase in their pickup in the one channel must be balanced by a corresponding decrease in the other, depending on the exact angle of sound origin.

It is exactly like the problem of designing a proper pan-pot circuit for a mixing console.  Coincident figure-8s crossed at 90 degrees give the closest match of any possible arrangement of any possible first-order directional pattern to the curve that is wanted for this purpose.

The main reference that I want to supply will be to one or more of Prof. Michael Williams' AES papers; the only question is to which one or ones.  What he has done for those of us who mainly record in stereo with two microphones, with his straighforward experimental research and use of mathematics, is virtually to eliminate a big source of guesswork and errors in microphone selection and placement.  I met him at the last NY AES, have a big pile of his writings here which he graciously gave me, and I'm looking forward to working my way through all of them this summer--I wish I could have done so sooner.

The biggest technical concern which unfortunately prevents the use of a Blumlein miking arrangement in many situations is its fixed, 90-degree stereo pickup angle:  all direct sound must originate from within the forward-facing quadrant of the stereo microphone array.  If any discrete sound sources are 45 degrees or farther from the front-facing center line of the array, they will create phase conflicts between the channels (because they'll also be picked up by the rear lobe of the other channel's microphone, in inverse polarity), and they will not image correctly.

Thus with an orchestra or chorus, for example, that is set up in the usual rather wide type of arrangement, a Blumlein pair must be pulled away far enough that it "sees" them as occupying 90 degrees or less of arc.  In many halls that is simply too far from the ensemble, especially when you consider that the back of a figure-8 microphone is every bit as sensitive as the front; there will not be enough direct sound in the balance, or the amount of hall sound may be OK but the character of that sound may not be pleasing, so you have to reduce it.  In such cases a different directional pattern must be chosen, e.g. supercardioid, or a different recording technique (not X/Y) must be used, e.g. ORTF, "sphere," A/B, etc.

There are other potential disadvantages and problems with a Blumlein arrangement, but such is the real world; I think no one here is very likely to believe that any one microphone arrangement is inherently perfect and should be used everywhere for every purpose.  So for now at least, I'll stop listing the disadvantages and simply say that I agree, Blumlein is a wonderfully effective arrangement if and when it is suitable.

--best regards
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otek

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Re: The glorious Blumlein
« Reply #2 on: June 12, 2004, 08:44:05 PM »

 Surprised    *click*


Connection made. David Satz does it again!


It's pretty scary how much of what you say jibes with my own subjective and totally unscientific impressions.

I have, for instance, found the Blumlein hard to use on large choirs and string ensembles, and awesome on string quartet, drum kit ambience and organ.

I have never made the connection that it has to do with the "width" of the sound source, however. It's just that when I've tried to use it on, say, a choir, I have had really weird impressions of the stereo image, and loss of low end information. Whereas on a quartet, drum kit or a piano/cello/vocalist trio, it's sounded magnificent.

Something that's kind of bothered me, at least as a theoretical concept, is how the reflections from the back of the room/hall line up in terms of phase with the direct sound. I haven't subjectively perceived this as a problem, although I have noticed that the sound becomes clearer if the distance to the back wall is at least equal to, and preferably greater than the distance from the mic setup to the ensemble. When recording drums in a smaller room, for example, the Blumlein didn't sound all that great when placed too close to the wall behind it.

David, any comments on this?
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ted nightshade

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Re: The glorious Blumlein
« Reply #3 on: June 12, 2004, 09:26:38 PM »

How close can you fake it with a pair of supercardioids? If that's not too general a question...
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otek

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Re: The glorious Blumlein
« Reply #4 on: June 12, 2004, 10:21:43 PM »

Ted,

I am not the expert David Satz is on this topic, but I can tell you with some certainity that you will not get very close with supercardioids.

The 180 degree pickup of most supercardioids (someone slap me if I'm wrong here) is frequency-dependent, whereas with a figure-eight, it's pretty uniform. This is essential to the Blumlein sound.

I have used two supercardioids for overheads and other stereo duties before, which works fine if the capsules are as close together as possible. I generally prefer regular cardioids for this, however.
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Yannick Willox

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Re: The glorious Blumlein
« Reply #5 on: June 13, 2004, 06:51:28 AM »

If I'm correct :

the figure of eight polar response is one of the least frequency dependent (in a good bidirectional mic design).
As a result angular distortion of a crossed pair is the lowest of all mic techniques (some blended techniques come quite close, if I recall correctly eg ORTF).

So replay will resemble the original stereo image like no other technique.

However, this immediately exposes THE big drawback : one should play blumlein recordings on speakers that are spaced 90 degrees instead of 60 ! (a good blumlein recording on a normal speaker setup sounds great, if you space the speakers 90 degrees it sounds 'real')

Another problem is the big directivity in the horizontal plane, which can give big problems in halls were most of the good ambient info comes from the floor/ceiling.
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David Satz

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Re: The glorious Blumlein
« Reply #6 on: June 13, 2004, 09:55:25 AM »

Hello, Ted--

> How close can you fake it with a pair of supercardioids?

This question opens up a set of several large issues all at once. Coincident supercardioids let you capture a wider angle of incoming sound than coincident figure-8s can; also, with condenser microphones at least, you will generally get fuller low-frequency response from supercardioids than from comparable figure-8s. Depending on the type of music you're recording and the type of hall you're in, those considerations can be crucial. The "down side" is that with supercardioids the stereo image in playback will emphasize the center artificially to some extent, though not as badly as coincident cardioids will.

More important to my ears is that, while supercardioids pick up less reverberant sound than figure-8s at any given miking distance, what they pick up contains a different, and to my ears less favorable, mix of reflected sound than the mix which figure-8s tend to pick up.

Let me try to explain that a little.  Both types of microphone are technically bidirectional--they each have a front lobe and a rear lobe, with the rear lobe being in opposite signal polarity to the front.  The difference between the two patterns, of course, is that in a figure-8 microphone the two lobes are equal while in a supercardioid the front lobe is emphasized--it is considerably more sensitive, and also broader, than the back lobe.  That extra broadness of the front lobe is what allows a pair of supercardioids to capture a wider array of performers on a stage than a Blumlein pair can capture, but there is both a direct and an indirect price to be paid for that ability.

Keep in mind that reverberant energy coming from behind the microphones is very likely to have travelled farther, to be more diffuse in character (with fewer identifiable, discrete reflections) and thus less likely to distract from the main image, and to have undergone a greater degree of high-frequency absorption both from multiple bounces off of hall surfaces and simply from the greater distance that the sound has travelled through the air before reaching the microphones.  Consider this:  You can take two microphones with any different directional patterns (say figure-8 and supercardioid), and place each one at a point in the hall where the ratio of direct sound to reverberant sound is exactly alike between the two of them (e.g. a figure-8 would need to be closer in than a supercardioid).  But if you do that, even though the amount of direct sound and the amount of reverberant sound will be the same in the two microphones, the one which is farther away will be picking up more of its quota of reverberant energy from the front and sides of the stage rather than from the back of the hall.  Those are, on average, shorter path lengths for the sound waves.  Thus it will be picking up more early reflections and a brighter and/or harsher selection (if you will) from the total body of reverberant sound energy that is available in the hall.  Generally, that's not preferable.

Here's the thing:  I've recorded with supercardioids (or something between super- and hypercardioid, which is what most such microphones really are) more than any other single pattern, so obviously I think they're one of the most useful types of microphone.  But that has been largely from necessity--because of the low-frequency issues, the geometric limit of a 90-degree pickup angle from a Blumlein pair, and for another big reason which is not about microphones but about performing spaces.  Let me just say that I am quite unhappy, one way or another, with the sound of most halls that I currently hear music performed in.  I do not think that those of us in the U.S.A. live in an age of really good architectural acoustics for music; we live in an age of "multi-purpose" spaces that aren't really good for any particular purpose.  I've lived in New York City for the past 23 years and the pleasant, naturally well-balanced spaces for performing music here are few, far between and expensive to rent.

Poor hall acoustics is the big elephant in the living room that no one talks about and that everyone is so used to that we just walk around it and work around it as if it were nothing worth mentioning.  But a Blumlein arrangement is hopelessly dependent on favorable acoustics in the way that a sailboat is dependent on the wind blowing in the right direction for your journey--and acoustics that allow you to use Blumlein stereo to best advantage are unfortunately rare.

Finally, there's one more big factor to consider that isn't strictly about microphones or patterns, but about overall geometry, balance and clarity.  As I've said, a Blumlein stereo array is limited to a 90-degree front pickup angle, and when you need to record something that is wider (from the microphones' point of view), you need to choose another pattern and/or another technique.  The question I'd raise is whether coincident stereo is really the best choice at all when a performing ensemble is so wide that you can't fit it into a 90 degree pickup angle and keep a good reverberation balance.  My concern is not so much a matter of angles as it is of the range of distances between all the performers and the microphones.

Most "main microphone" setups (coincident, spaced or in-between) are placed closer to the front of the stage than most members of the audience are sitting, even in the good seats.  This distorts the perspective of the recording somewhat, because relatively speaking, the closest performers are closer to the microphones than the farthest performers are by a far greater ratio than is true for the audience.  This affects the musical balance both in terms of volume and clarity.  The string section tends to overwhelm the pickup, with the front desks being perhaps 5 to 10 times closer to the microphones than the back desks of the same section of players.  If there is a soloist in the front (e.g. in a piano concerto) the soloist may literally be 20 times closer to the microphones than the people at the end of the back row of the orchestra.  Twice as close might make sense from a balance standpoint, but certainly not 20 times as close.

Say what you will about phasiness and vague imaging in spaced microphone arrangements, but at least they are not the worst case in this regard; coincident arrangements (of any kind) are the worst case.  If the hall acoustics and your choice of recording method and microphone pattern(s) don't let you get some appreciable distance from the front ranks of the performers, you will get sound that is too loud and clear from them and too fuzzy and distant from the players in the back--who are (or should be) just as good musicians as the ones in the front.

I'm sorry that again this is a very long message, but I think that it's a mistake to treat microphone patterns as abstractions when in practice they bring all these other concerns into play.

--best regards
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otek

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Re: The glorious Blumlein
« Reply #7 on: June 13, 2004, 09:57:12 AM »

Yannick Willox wrote on Sun, 13 June 2004 12:51

Another problem is the big directivity in the horizontal plane, which can give big problems in halls were most of the good ambient info comes from the floor/ceiling.



Another thing that hadn't occurred to me - The floor-to-ceiling reflections would be attenuated with the Blumlein technique, and the horizontal reflections emphasized.


Thanks Yannick!
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otek

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Re: The glorious Blumlein
« Reply #8 on: June 13, 2004, 10:09:25 AM »

David,

We seem to have responded simultaneously!

Thanks again for your wisdom, which - of course - brings new questions... two of them, to begin with:

1) I have heard some great recordings from a place in New York called the "Troy Concert Hall". Did you ever record there? Any comments about the location?

2) What if one were to complete the blumlein with a pair of omni mics, to make up a "Decca tree" of sorts. Would that help with the low-frequency issues with the blumlein? Would it cause more problems with phase?
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ted nightshade

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Re: The glorious Blumlein
« Reply #9 on: June 13, 2004, 11:29:33 AM »

Schoeps makes a thing called a LP 40, a low pass filter where the -3dB point is 40 Hz (12dB/octave) "for filling in the bass region of the frequency response of directional microphones". Yes, it's meant to be used with an omni, and is meant especially for the Schoeps supercardioid, but also useful for other types, including figure 8.

I'm sure you could do a similar low-pass scheme with other makes of mics and get suitable results.

David, thanks again very much for every bit of your lengthy reply. Yes, those early reflections... sigh... and those acoustic spaces... sigh again.

I wonder if there's an angle at which the exaggeration of the center of the image would be minimized using a pair of coincident (or ORTF) supercardioids. The ones I have in mind (Schoeps) have well-balanced off-axis response, so that could work I think. But for those early reflections... what a mess that is....

Filling in the bass with omnis, what a concept...
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David Satz

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Re: The glorious Blumlein
« Reply #10 on: June 13, 2004, 04:50:16 PM »

Otek:  I assume that you mean the "Troy Savings Bank Music Hall" in Troy, New York--an absolutely enormous auditorium which may be the Western hemisphere's largest extant stone shoebox.  I've never recorded there, but I have been recorded there; as it happens, the one CD still available on which I can be heard as a professional musician was recorded in that hall.  It's a live recording of a Mozart concert from 10+ years ago--the New York Philomusica chamber ensemble with Robert Johnson conducting.  The recording was made by the great team of Marc Aubort and Joanna Nickrenz ("Elite Recordings"--the same folks who made so many wonderful Nonesuch records with the late Tracy Sterne as producer), using a pair of Schoeps M 221 B microphones (M 934 B capsules in the omni setting, I believe).

The recording is noteworthy for the fact that Robert Levin is piano soloist in the big G major concerto (K 453) and as always, he improvised his cadenzas.  Plus there's a very nice performance of the G minor string quintet K 516.  The track that I'm on is the Masonic Funeral Music--if you hear a very odd sounding woodwind instrument in the tenor range, that's the bottom one of the three basset horn parts.  It's an amazingly rich orchestration, and it worked better in that hall than I've ever heard it work anywhere else before or since.
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otek

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Re: The glorious Blumlein
« Reply #11 on: June 13, 2004, 10:54:05 PM »

ted nightshade wrote on Sun, 13 June 2004 17:29

Schoeps makes a thing called a LP 40, a low pass filter where the -3dB point is 40 Hz (12dB/octave) "for filling in the bass region of the frequency response of directional microphones". Yes, it's meant to be used with an omni, and is meant especially for the Schoeps supercardioid, but also useful for other types, including figure 8....




Shocked



Imagine getting your levels and balances right with that one - what a nightmare!


David, "The western hemisphere's largest shoebox" doesn't exactly sound like a thumbs-up!  Laughing

However, I got the idea you like the hall. Must check out that recording - what's the label and number?

Note - the stuff I heard before are a couple of recordings on the Dorian label, among others Ottorino Respighi's "The Pines Of Rome"... which seems to lend itself to that type of sound, as well... bombastic indeed!
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Jan

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Re: The glorious Blumlein
« Reply #12 on: June 14, 2004, 04:10:28 PM »

Something that came to my mind when reading about low freq. stuff and omni mic's:

the difa: diffuse field adapter.
A dutch invention which adds directivity to low freq pickup.

http://www.felixsonaudio.nl/en/difa/
I don't know, but why blumlein instead of A-B with omni's? That also seems to have good localisation...
I never did blumlein so I can't compare myself (though i've heard blumlein recordings but not with the awareness towards sound etc i have build up last 6 months).
David, can you maybe tell something of your experience with it?

I try to figure out myself (with the image assistant and my little knowledge about acoustics), but am curious about your explaination.
Image assistant (as ppl might not know it, it's great when comparing mic techniques): http://www.hauptmikrofon.de/ima2.htm
(requires java)

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Schallfeldnebel

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Re: The glorious Blumlein
« Reply #13 on: October 09, 2004, 10:18:37 AM »

"A Blumlein stereo array is limited to a 90-degree front pickup angle, and when you need to record something that is wider (from the microphones' point of view), you need to choose another pattern and/or another technique".

You can stay very close to Blumlein XY and use Blumlein MS. You turn the set 45 degrees, and use one 8 as M signal and use the side 8 as S signal. Now the group can sit wider than 90 degrees.

"The floor-to-ceiling reflections would be attenuated with the Blumlein technique, and the horizontal reflections emphasized".

That you can get under control by using a third figure of 8, which looks up to the ceiling and down to the floor. If you matrix this to stereo you can regulate the width and floor ceiling reflections, and the "commonground" problem mentioned by David Satz is better controlled in Blumlein MS too.

Erik Sikkema


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David Satz

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Re: The glorious Blumlein
« Reply #14 on: October 09, 2004, 01:23:31 PM »

Erik,

I think this is either a misstatement or a misunderstanding. With bidirectional microphones of equal sensitivity, when you matrix from M/S to stereo left and right, any discrete sound source that was originally located farther from front-and-center than +/- 45 degrees will be picked up more strongly in the difference ("S") channel than in the sum ("M") channel. It will thus appear in inverse polarity in the "opposite" speaker to some extent. This causes phasey "wraparound" imaging, just as it would with a classic Blumlein pickup.

Converting from a Blumlein setup to mid-side technique doesn't increase your stereophonic recording angle unless you either use a broader front pattern for the "M" microphone (e.g. a supercardioid), or reduce the input from the "S" microphone and give up a significant amount of reverberant sound and stereo separation in the process. Otherwise you are still limited to a stereophonic pickup angle of 90 degrees as "seen" from the pair of microphones.

--best regards
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Schallfeldnebel

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Re: The glorious Blumlein
« Reply #15 on: October 09, 2004, 02:33:38 PM »

Hi David

As you wrote to use less from the side mike, that's the possibility I was thinking of you have with the MS you don't have with the XY, unless you minimize the 90 degrees angle of the classical Blumlein.  

The reverb coming from the opposite direction of the XY Blumlein, comes in channel reversed, does it also in MS, since the back of the M 8 is out of phase changing the channel in the matrix?

If this is so, is there a mathematical proof that classical Blumlein XY is the same as Mid Side Blumlein?

Best,

Erik Sikkema  
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hollywood_steve

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Re: The glorious Blumlein
« Reply #16 on: October 09, 2004, 03:27:03 PM »

or a different recording technique (not X/Y) must be used,

David, could you please explain why you think X/Y would be wrong in this situation?   I recently obtained a second Coles 4038 and I am now always on the lookout for a good opportunity to use Blumlein.  But no matter what else I was trying, I have always used XY stereo as my fallback stereo pattern.  Probably because I didn't have a good way to mount mics in an ORTF or NOS pattern.  The Shure A27M just made XY so easy and the results have ranged from OK to pretty good.  But I am curious to learn of your issues with the XY pattern?

Now that I have one of the AEA stereo bars, it is a lot easier to setup a NOS or ORTF array (although a couple of right angle XLR connectors also make things a lot easier - two cables can't occupy the same space very easily).

Most of my gigs are "rush jobs" where I am running hard to get set up by the start of the session.  I'm really looking forward to some slower gigs where I might actually have the time to compare an ORTF pair against an XY pair, that would be a real luxury.
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djui5

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Re: The glorious Blumlein
« Reply #17 on: October 10, 2004, 03:10:57 AM »

Jan wrote on Mon, 14 June 2004 14:10



Image assistant (as ppl might not know it, it's great when comparing mic techniques): http://www.hauptmikrofon.de/ima2.htm
(requires java)






That thing is awesome....thanks for sharing!
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David Satz

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Re: The glorious Blumlein
« Reply #18 on: October 10, 2004, 09:09:14 AM »

Hi, hollywood_steve--

Coincident recording methods have undeniable advantages--image stability and mono compatibility are the two biggies, and simplicity is a very good thing, too. But to get those goodies when the hall and/or the arrangement of performers is less than ideal, X/Y recording always forces you to give up something else that you want in the recording. If that "something else" is a decent overall balance among the instruments or voices without favoring the front/center performers too strongly, it's time to start making intelligent compromises with the recording method.

I was talking about one basic problem of recording a large ensemble that occupies a wide stage. In that situation, a pair of centrally-placed coincident microphones may be literally ten times closer to the players nearest the conductor's position than they are to the farthest players. This makes the front and center players seem louder and clearer than all the other players. The extent of this effect will depend on the actual distances involved and the characteristics of the hall. Listeners in the audience always hear some amount of this effect, too, so it isn't something that absolutely must be overcome completely. (That's fortunate, since there would be no practical way to do so.) Rather, it's a matter of degree--of not having too much of any one bad thing, so to speak.

If the microphones are moved closer to the ensemble, the contrast in clarity and loudness due to the differing pickup distances will increase, while if the mikes are moved farther back and/or up, it will all "even out" more. But varying the overall distance also affects two of the other primary factors that we have to care about: the balance of direct vs. reverberant sound being picked up and the stereo image width. No law of the universe guarantees us that the optimal distance for any of these three "matters of degree" will match the other two at all. The contrary is more often true, in my experience.

The worst case is that there are particular situations in which the microphones must be placed relatively close to an ensemble--the hall is too reverberant or too noisy; the character of the hall sound is not so pleasant; the program material requires extra clarity; you have no access to places in the hall from which to "fly" the microphones; your favorite brand of oxygen-free microphone cable is so expensive that you can only afford 18 inches of it. In those cases, spaced microphones (especially if they're relatively widely spaced--the style often favored in the U.S.) will give you some extra "wiggle room" to choose a miking distance without favoring the front and center performers quite as much as a central X/Y pair would do.

--best regards
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judah

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Re: The glorious Blumlein
« Reply #19 on: October 13, 2004, 02:45:35 AM »

otek wrote on Sat, 12 June 2004 06:31

I have used the Blumlein configuration quite extensively for ambience miking, and I have usually been very pleased with the sound. It seems to give a very exact, three-dimensional representation of most ensembles, provided the room is good, and provided I keep plenty of distance to the walls in all directions (I am not sure if this is actually necessary, it's just the way it's sounded to me every time).

Now, I mostly go entirely by subjective opinion. I listen, and if I like it, I use it. Which has been the case with this technique.

But I would definitely be interested in hearing what the theoretical background to the Blumlein configuration is. I don't know how to explain this in correct technical terms, so bear with me here, but I have imagined that its precise nature and ability to pinpoint instruments in the stereo field comes from the fact that the pickup pattern of each figure-eight shares very little "common ground" with the other, and therefore the stereo image becomes clearer.

Am I full of crap here? Can someone explain it to me in a better way?


Hi,
a bit off but still in topic. If anyon eof you has some hours of free time to dedicato to reading, there's an very interesting book about Blumlein. He was a marvelous genius of his time and really was into something.
Here's the details:

The Inventor of Stereo: The Life and Works of Alan Dower Blumlein, by Robert Charles Alexander

"Alexander, a consultant studio engineer who works in radio, unearths the memory of Blumlein (1903-42), whom he considers one of Britain's most important inventors. He particularly describes his 1931 patent for a Binaural Recording System. Others of his 128 patents during his short life were for the principal electronic circuits critical for electronic television, and others that broke new ground in electronic and audio engineering. He died in a plane crash while working on secret radar research for World War II."

Amazon link:
http://www.amazon.com/exec/obidos/tg/detail/-/0240516281/qid =1097649827/sr=1-1/ref=sr_1_1/002-3039984-5248006?v=glance&a mp;s=books

Happy reading.

R.
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Gunnar Hellquist

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Re: The glorious Blumlein
« Reply #20 on: October 13, 2004, 03:37:46 AM »

Steve wrote:
>>Now that I have one of the AEA stereo bars, it is a lot easier to setup a NOS or ORTF array (although a couple of right angle XLR connectors also make things a lot easier - two cables can't occupy the same space very easily).

Hi Steve. Well-known problem to me. I tend to use a small standoff made from some odd bits and pieces to get one of the microphones an inch or so higher than the other. The back ends and the cables then does not interfer as much.

Schoeps has another solution on that problem in the UMS20. Note how the micholders bend in the "wrong" direction compared to other holders. This allows you have the the mics at different heights. (The best pic I found at a quick search is from a dealer, just to be clear, I have never had any dealings with them)
http://www.posthorn.com/S_ums20.html

Gunnar Hellquist
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davidl

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Re: The glorious Blumlein (a somewhat OT addendum)
« Reply #21 on: October 18, 2004, 04:15:30 AM »

Hello David S

"The recording was made by the great team of Marc Aubort and Joanna Nickrenz"

I haven't seen Marc & Joanna since the original Nonesuch was destroyed in 1979 with the firing of Tracey by Elektra management. (I'd like to be really rude about the people who did it, but this isn't the right place!) Are Marc & Joanna still in business?

The Nickrenz who is making a stir nowadays is Joanna's daughter Erica, pianist of the Eroica Trio.

I still remember Marc & Joanna recording Nonesuch sessions in the Judson Church, lid off the piano, a pair of spaced mics overhead -- and subway rumbles frequently audible from beneath the church. Tracey usually provided a Baldwin, but Paul Jacobs got a Bosendorfer for his Debussy sessions.

Salutations, David Lewiston
The Lewiston Archive, Recordings & Documentation of the World's Traditional Music
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ted nightshade

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Re: The glorious Blumlein (a somewhat OT addendum)
« Reply #22 on: October 18, 2004, 11:01:29 AM »

davidl wrote on Mon, 18 October 2004 01:15


I still remember Marc & Joanna recording Nonesuch sessions in the Judson Church, lid off the piano, a pair of spaced mics overhead -- and subway rumbles frequently audible from beneath the church. Tracey usually provided a Baldwin, but Paul Jacobs got a Bosendorfer for his Debussy sessions.

Salutations, David Lewiston
The Lewiston Archive, Recordings & Documentation of the World's Traditional Music



That's a Bosendorfer huh? On Images for Piano? I was listening to that after listening to Monk and Ellington and Alice Coltrane and saying, "man, what a beautiful American piano sound! How *percussive*!" Well I guess that old Bosendorfer was really different from the new ones I've heard. Spaced mics, eh? (attempt to remain topical)
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davidl

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Re: The glorious Blumlein (a somewhat OT addendum)
« Reply #23 on: October 18, 2004, 02:56:54 PM »

Just did a web search and discovered that Joanna died in '02. Too many of the old Nonesuch family have now left us, first Paul, then Jan de Gaetani, Tracey, and Joanna.

Oh well...

David Lewiston
The Lewiston Archive, Recordings & Documentation of the World's Traditional Music
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Chris Cavell

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Re: The glorious Blumlein (a somewhat OT addendum)
« Reply #24 on: October 20, 2004, 11:29:38 AM »

A good resource on stereo mic techniques, including blumlein and modifications to blumlein techniques: "Basic Stereo Microphone Perspectives--A Review" by Ron Streicher and Wes Dooley published in the Journal of the AES in 1985, vol. 33.

From the aes.org site:
Quote:

Volume 33 Number 7/8 pp. 548-556; July/August 1985
This paper is a review of the methods used for creating illusions in stereo, with common configurations utilizing two, three, and four microphones. It presents the placement and type of microphones used for each configuration, and discusses their basic characteristics, advantages, and disadvantages. All of the techniques discussed have produced satisfying results. The use of a particular technique will depend on circumstances; the source source, the recording environment, the desired effect, and the release format.
Authors:   Streicher, Ron; Dooley, Wes
E-lib Location: (CD aes4)   /jrnl7888/1985/8059.pdf

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ted nightshade

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Re: The glorious Blumlein (a somewhat OT addendum)
« Reply #25 on: October 20, 2004, 11:52:09 AM »

Chris Cavell wrote on Wed, 20 October 2004 08:29

A good resource on stereo mic techniques, including blumlein and modifications to blumlein techniques: "Basic Stereo Microphone Perspectives--A Review" by Ron Streicher and Wes Dooley published in the Journal of the AES in 1985, vol. 33.




I have this and can recommend it, and especially the AES publication "Stereo Techniques- an Anthology" in which it appears. (hope I got that title right, it's very similar anyway).
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locosoundman

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Re: The glorious Blumlein
« Reply #26 on: October 27, 2004, 12:11:17 PM »

hello

Great discussion, just wanted to add this:

I have a few T-Bars, but have found the Sabra-som one to be the most flexible in my arsenal (don't have $500 to spend on the Schoeps mount - wish I did).  But you often have to get creative with the mount you have to get the proper angle and spacing.  I actually mount the bar sideways angled at 90 degrees with the mics one over the other using the mic clip itself to get the proper angle.  Would be great if had had a picture to show - I don't know if this visual is clear or not.

I read one book when I first started out that really was helpful to me - Bruce and Jenny Barlett's "On-Location Recording Techniques."  I think they basically just reprinted the "Stereo Mic" book that they had, but the information was well-presented without getting overly technical and I found it to be a useful resource.  I love the AES journal, but I usually get the most out of it during my first-cup-of-morning-coffee read.

Best,
Rob
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Jørn Bonne

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Re: The glorious Blumlein
« Reply #27 on: April 25, 2005, 04:48:33 AM »

Yannick Willox wrote on June 13, 2004:

However, this immediately exposes THE big drawback : one should play blumlein recordings on speakers that are spaced 90 degrees instead of 60 ! (a good blumlein recording on a normal speaker setup sounds great, if you space the speakers 90 degrees it sounds 'real')

How about modifying the Blumlein setup and use an inclusive angle of 60 degrees instead of 90? I've tried it recording steel string guitar from about a foot away. Seems to work allright with a rather narrow soundstage like that. Any comments on potential problems?

Thanks

J
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recordista

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Re: The glorious Blumlein
« Reply #28 on: April 26, 2005, 04:59:44 PM »

Yannick Willox wrote on Sun, 13 June 2004 11:51

one should play blumlein recordings on speakers that are spaced 90 degrees instead of 60 ! (a good blumlein recording on a normal speaker setup sounds great, if you space the speakers 90 degrees it sounds 'real')


Try a pair of planar speakers at 90
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Kurt Albershardt
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Re: The glorious Blumlein
« Reply #29 on: April 26, 2005, 05:05:22 PM »

hollywood_steve wrote on Sat, 09 October 2004 20:27

I have always used XY stereo as my fallback stereo pattern.  Probably because I didn't have a good way to mount mics in an ORTF or NOS pattern.  The Shure A27M just made XY so easy and the results have ranged from OK to pretty good.


I use my A27M for ORTF regularly.  Have you tried that?
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Jørn Bonne

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Re: The glorious Blumlein
« Reply #30 on: April 28, 2005, 03:38:35 AM »

Bump!!


Yannick Willox wrote on June 13, 2004:

However, this immediately exposes THE big drawback : one should play blumlein recordings on speakers that are spaced 90 degrees instead of 60 ! (a good blumlein recording on a normal speaker setup sounds great, if you space the speakers 90 degrees it sounds 'real')

How about modifying the Blumlein setup and use an inclusive angle of 60 degrees instead of 90? I've tried it recording steel string guitar from about a foot away. Seems to work allright with a rather narrow soundstage like that. Any comments on potential problems?

Thanks

J
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Yannick Willox

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Re: The glorious Blumlein
« Reply #31 on: April 30, 2005, 02:06:14 AM »

There seems to be a consensus that crossed eights should be 90 degrees only, however we regularly use two bidirectionals in an MS configuration. Varying the S signal doesn't seem to have obvious drawbacks (in most situations). This is basically the same as physically changing the angle.
Making the angle bigger (adding S signal) tends to give too much out of phase information.

If it sounds right, it must be right ?
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ted nightshade

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Re: The glorious Blumlein
« Reply #32 on: May 03, 2005, 05:59:33 PM »

I'd like it if everybody had their stereo speakers at a 60 degree angle, but they're liable to be pretty much any way at all...
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Re: The glorious Blumlein
« Reply #33 on: May 17, 2005, 02:55:45 AM »

hi, was listening to "kamara musicin native tounges" by waterlilly records. they claim to have done the recoding by blumlein. i do not know if u have heard it, but the guitas and vocals sound much louder than the violin {played karnatic style} and the indian percussion, mridangam, sounds a lot lower. now, i have never used the technique and do not know what  went wrong there but could it be that the 2 guitar players{also singing} were sitting on stools and the indian players sitting on the ground{as they usually do} made so much of a difference in the recording levels?4 people should not be that difficult to record, i am puzzled by it.

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Barry Hufker

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Re: The glorious Blumlein
« Reply #34 on: May 17, 2005, 07:28:11 AM »

I am not familiar with that recording, but it could be the singers were closer than the other instruments.  I would think the producer/engineer would have thought carefully about the "soundstage" and musical balance when recording.  I can only assume that how you hear it is how they meant if to sound.

Stereo is supposed to be three dimensional.  All too often the concept of "depth" is left out of modern recordings.  I would say that as long as the instruments are in the proper balance (and maybe you're suggesting they aren't), then it is a nice change to have musicians close and far.  That's how you would have heard them in a live performance.

Barry
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Future_One

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Re: The glorious Blumlein
« Reply #35 on: February 15, 2010, 08:45:51 PM »

Lots of good knowledge in this thread.

Cheers,



Mark Sloane
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Klaus Heyne

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Re: The glorious Blumlein
« Reply #36 on: February 16, 2010, 01:41:05 PM »

Barry Hufker wrote on Tue, 17 May 2005 04:28

 Stereo is supposed to be three dimensional.

Correct me if I am wrong, but I was under the impression that a conventional 2-channel recording cannot render a three-dimensional image, only the illusion of one.

Such illusion is fairly well recreated psycho-acoustically with binaural headphones, after binaural (ear canal-like) treatment before the sound waves enter the microphone capsules (dummy head, f. ex.)
But any true three-dimensional rendering would require more than two recording channels and more than two playback channels/speakers.
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