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What is this microphone array?
Old 4 weeks ago
  #1
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robert82's Avatar
What is this microphone array?

I'm intrigued. See 0:14

Old 4 weeks ago
  #2
The industry standard small AB pair of TLM170s and a mono M49 in between for a bit of color.

Quote:
Originally Posted by robert82 View Post
I'm intrigued. See 0:14

Old 4 weeks ago
  #3
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Another recording, same config.
https://www.youtube.com/watch?v=pls5Yzzw1yM
Old 4 weeks ago
  #4
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robert82's Avatar
I'm guessing if there are any phase issues, they would concern pretty high frequencies?
Old 4 weeks ago
  #5
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Quote:
Originally Posted by robert82 View Post
I'm guessing if there are any phase issues, they would concern pretty high frequencies?
It's hard to tell the distance the central (M49 ?) mic is set back from the 170's, but they're certainly not all in a line.
My guess is the mix levels of the 3 (as spots) aren't equal either. More likely, similar to the inner vs outer pairs of a Boojum/Norman/Faulkner array, there'd be enough of a difference (in the level of the centre vs outer pair) that phase won't become a significant thing.
Old 4 weeks ago
  #6
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Quote:
Originally Posted by robert82 View Post
I'm guessing if there are any phase issues, they would concern pretty high frequencies?
of course: you can calculate the frequencies with the possibly highest degree of phase cancellation by the distance between the mics (and use this to decide on the spacing)...
Old 4 weeks ago
  #7
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Quote:
Originally Posted by robert82 View Post
I'm guessing if there are any phase issues, they would concern pretty high frequencies?
Just an estimation looking at the distance between the middle microphone and one on the side aprox. 20 cm = 1.700. Better not have them all at the same level I assume.
Old 4 weeks ago
  #8
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Plush's Avatar
It is basically a mono pick up so no phase problems.
Old 4 weeks ago
  #9
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jimjazzdad's Avatar
Quote:
Originally Posted by Plush View Post
It is basically a mono pick up so no phase problems.
So both mics panned centrally or one TLM170 hard left and the other hard right? The latter would seem to be the only way to avoid comb-filtering.
Old 4 weeks ago
  #10
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The two TLM170 would be panned hard left and hard right so solid central image. Bringing up the M49 could cause combing, but since most of the sound is direct and from the front, ie hitting both the M49 and TLM at nearly the same time, the phase differences arising from mixing would be small.
Old 4 weeks ago
  #11
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not necessarily true:

even with capsules (of two different types of mics) being relatively close such as in this example, one can easily measure a phase offset - however (and that's the point!), some phase offset can lead to very pleasing results...

...or else there wouldn't be this many engineers using spaced omnis for both spots and mains!
Old 4 weeks ago
  #12
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Quote:
Originally Posted by deedeeyeah View Post
not necessarily true:

even with capsules (of two different types of mics) being relatively close such as in this example, one can easily measure a phase offset - however (and that's the point!), some phase offset can lead to very pleasing results...

...or else there wouldn't be this many engineers using spaced omnis for both spots and mains!
But spaced omnis, one for each loudspeaker, are not mixing non-coincident but close signals together to mono as in the example being discussed here.
Old 4 weeks ago
  #13
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Quote:
Originally Posted by David Spearritt View Post
But spaced omnis, one for each loudspeaker, are not mixing non-coincident but close signals together to mono as in the example being discussed here.
the 'problem' remains: you get overlap, both on the recording and on the playback side, regardless of panning/mixing/routing - compare to a coincident system and feed signals into an goiniometer or fft if you cannot believe...
Old 4 weeks ago
  #14
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fred2bern's Avatar
Could be also 2 spot options, one hard left and right in stereo (170) and one in mono, no mix but a decision at the end listening to the color and how it fits into the main pair.
I sometimes spot with 2 separate options to get the opportunity to find the best match at the end.

Last edited by fred2bern; 4 weeks ago at 09:03 AM..
Old 4 weeks ago
  #15
How many trumpeters does it take to change a lightbulb?

One, and a dozen to talk about how they would have done it better.

Wait, I’m sorry, that was supposed to be about armchair AE’s on GS.
Old 4 weeks ago
  #16
This is a very common technique amongst the top classical AE’s in the world. Probably worth all of our time to figure out how to use it correctly instead of talking sh!t on the internet.
Old 4 weeks ago
  #17
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fred2bern's Avatar
Quote:
Originally Posted by king2070lplaya View Post
This is a very common technique amongst the top classical AE’s in the world. Probably worth all of our time to figure out how to use it correctly instead of talking sh!t on the internet.
bad night?
Old 4 weeks ago
  #18
Quote:
Originally Posted by fred2bern View Post
bad night?
i had a fine night. I even used a coincident stereo mic.

I just feel it would be insincere not to express my growing frustration with the almost audiophile-esque level of ignorance and pompousness which has permeated this forum recently.
Old 4 weeks ago
  #19
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Quote:
Originally Posted by fred2bern View Post
Could be also 2 spot options, one hard left and right in stereo (170) and one in mono, no mix but a decision at the end listening to the color and how it fits into the main pair.
Hi Fred,
What I mean is when you mix a hard panned LR pair (170's) with a mid panned mono mic with a similiar level, you have half the mono M49 mixing with the left 170 and half the mono M49 mixing with the right 170, hence the potential for combing as they are not coincident.
Old 4 weeks ago
  #20
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Quote:
Originally Posted by king2070lplaya View Post
This is a very common technique amongst the top classical AE’s in the world. Probably worth all of our time to figure out how to use it correctly instead of talking sh!t on the internet.
It seems to be more common to just have the pair of 170's panned L and R, I think like Richard King described originally? The addition of another centre mic almost like a mini decca tree seems to be more recent judging from YouTube clips. (Definitive source?)
Old 4 weeks ago
  #21
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I have noticed multiple [2-3] mics on classical vocalists accompanied by small ensembles in the past. And I am still also wondering why?

I don't ever recall 2-3 mics in such a circumstance being used to affect any notable widening. So I've assumed it was strictly for coloration - embracing the effects of interference.

A link to a relevant article or dissertation or interview would be helpful.


Thanks,

Ray H.

Last edited by RayHeath; 4 weeks ago at 02:31 PM.. Reason: Removed very funny line about lightbulb and high-pass filter. Tune in early, or miss out on the humor forever.
Old 4 weeks ago
  #22
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Another example. Simple setup, couple of Schoeps, but no centre mic.
https://www.youtube.com/watch?v=12Vog4TZRtE
Old 4 weeks ago
  #23
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obviously none of us was imvolved in this particular recording or got to talk to the tech - nethertheless, it's fair to assume that

a) this is no mini-kinda-decca tree as a decca relies on far larger distance between the mics (and be it only for covering a much larger source)

b) this mic array was either chosen to base the mix on the center mic and use the spaced pair just to add coloration/ambience/widen the track/soundfield or

c) the mix relies on the spaced pair and the center mic got chosen to solidify the center image (statically or dynamically) or that

d) the tech wanted to have the option to blend or alternate between the latter two, depending on composition (in a moment without much accompaniment, the voice might appear a bit too wide).

there are different ways to achieve all of the above mentioned goals but there's no denying that ANY spaced array of mics yields a soundfield with less phase coherence than when using a coinicident system - again, there are ways to mitigate effects in case they become an issue or to use them to our advantage but effects of a partial phase offset do not magically disappear on playback...


___


EDIT:

@ ray: there's a ton of literature available dealing (directly or indirectly) with effects of phase coherence; i'm mainly thinking about those dealing with multi-capsule mic arrays - some are available from mic manufactures, some got published via aes and some are stemming from different field of our profession (and hence information needs go get transferred to mic technique, which is why i'm reluctant to post any examples in this forum or thread); you find the latter papers (and videos) less in a library as they mostly deal less with theoretical aspects but real real-world scenarios and how to use gear and apply technique.

[hint: fft, time domain, monitor speakers, acoustics but also (sub) array design, system alignment etc.: rather serious stuff for grown ups, no more vague guessing about phase...]

Last edited by deedeeyeah; 4 weeks ago at 12:12 PM.. Reason: edited twice
Old 4 weeks ago
  #24
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Quote:
Originally Posted by king2070lplaya View Post
i had a fine night. I even used a coincident stereo mic.

I just feel it would be insincere not to express my growing frustration with the almost audiophile-esque level of ignorance and pompousness which has permeated this forum recently.
A bit harsh Kevin, as all I see in this case are well intentioned guesses and speculation about how an obviously-oft used trio of spot mics manages to avoid phasing, in terms of real-world results ? Pure theory would suggest that phasing might be expected, and we're just advancing ideas as to how that's avoided by the pros we see on YouTube.

You probably have a few ex-Decca recording engineers on your speed-dial...call 'em up on our behalf and share the good oil here, to end the agony

Inquiring minds (genuinely) want to know....
Old 4 weeks ago
  #25
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Quote:
Originally Posted by David Spearritt View Post
It seems to be more common to just have the pair of 170's panned L and R, I think like Richard King described originally? The addition of another centre mic almost like a mini decca tree seems to be more recent judging from YouTube clips. (Definitive source?)
There might be complementary or competing needs for the spot mics here: to create a strong central image to anchor the voice timbrally and spatially (this could be done by angling the 170's out, ORTF like, to create a phantom centre), or by simply turning up the centre mic.

I'm guessing Plush might advocate facing all mics straight ahead, no angling, and pan the outer mics 10am and 2pm...for a 'solid centre'

The other need would be to prevent head and body turns by the singer from allowing the voice to dip out, either volume or presence-wise. Widely spaced mics on axis to the singer would rein that tendency in, because nobody wants lurching L/R image shifts on their CD !

Now, as for phase.....?
Old 4 weeks ago
  #26
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fred2bern's Avatar
Quote:
Originally Posted by David Spearritt View Post
Hi Fred,
What I mean is when you mix a hard panned LR pair (170's) with a mid panned mono mic with a similiar level, you have half the mono M49 mixing with the left 170 and half the mono M49 mixing with the right 170, hence the potential for combing as they are not coincident.
Dear David, I totally agree. That's why we can also imagine that the goal is not to mix the 3 microphones but to choose between 2 options.
By the way nice recording with the "Ma mère l'Oye" and Ensemble Q...
Old 4 weeks ago
  #27
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Thanks Fred. But master musicians performing a masterpiece like that, one cannot really go wrong.
Old 4 weeks ago
  #28
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Quote:
Originally Posted by deedeeyeah View Post
[. . .] @ ray: there's a ton of literature [. . .]

[hint: fft, time domain, monitor speakers, acoustics but also (sub) array design, system alignment etc.: rather serious stuff for grown ups, no more vague guessing about phase...]
Thanks, DD.

As you can imagine from my software dev history, I've implemented countless FFT and time domain algorithms. A long time back, I also took a course or two on psychoacoustics [that could use refreshing]. I do need to read through the sources you allude to. And I won't likely have trouble with the science or math.

But I am especially wondering why this is appealing to audio engineers for classical music vocalists.

I would naturally suspect that some significant number of them do it 'because they can'. . .not that that their insight from FFTs for the specific environment pressed them to do so.

But either way that coin falls, I wonder about their intention. What exactly were they hoping to achieve by adopting these configurations?

@ Plush expressed that [from his perspective] it is 'basically a mono pick up'.

I'm wondering about the delta between 'basically' and 'exactly' in their minds.


Many thanks,

Ray H.
Old 4 weeks ago
  #29
This is simply a spot pair of TLM170s, with mono m49 spot in between. The engineer likely makes a judgment as to whether they want to add width to a strong m49 signal, or add center to a strong 170 stereo image, and balances accordingly.

If you were to play tone from a speaker where the singer is, you might notice a wee bit of phasing as the volumes of the pair and mono mic reach an equal level. In practice, however, the effect can be avoided by careful listening while mixing, and avoiding mixing the signals too close in level to each other.

Unlike a Decca tree, The mics here seem to be in a line, or maybe even the m49 is a bit behind the 170’s, so one doesn’t benefit from the “forward gain” of having earlier time of arrival cues in the center mic. And that wouldn’t really be helpful or desirable in this instance.

Without being present for the session or the mix, or being in touch with the engineers, it is nearly impossible to know what the final balance was, though studying the sound of record should give some indication based on how strong the center image of the voice sound is.

I will see if I can go back and find some album EPK videos that feature similar setups to this. I think I remember a few off the top of my head that may be relevant.

Maybe I am misreading, and if so that is my fault, but there often seems to be a strong negative reaction to techniques demonstrated in posts like this, that such techniques “don’t work”, or don’t work well, or are inferior to other, better techniques, based on what I would describe as a shallow theoretical understanding of mic technique. I don’t much see the point in those responses, as they do not usually help to answer the questions posed by the OP’s of what they are seeing and why one would use a setup. That’s what I’m reacting to above. If you were to ask “what’s a good mayonnaise-based sauce for French fries?”, and received the answer that “mayonnaise is gross and you should prefer ketchup outright for X or Y objective reason”, well that’s not very helpful, is it?

(Edit to say that I looked this album up, it is engineered by Jonathan Stokes, who learned and worked under the greats at Decca in the 80s and 90s, and has a great many credits to his name. His use of this technique can be taken as a ringing endorsement of its effectiveness.)

Quote:
Originally Posted by studer58 View Post
A bit harsh Kevin, as all I see in this case are well intentioned guesses and speculation about how an obviously-oft used trio of spot mics manages to avoid phasing, in terms of real-world results ? Pure theory would suggest that phasing might be expected, and we're just advancing ideas as to how that's avoided by the pros we see on YouTube.

You probably have a few ex-Decca recording engineers on your speed-dial...call 'em up on our behalf and share the good oil here, to end the agony

Inquiring minds (genuinely) want to know....
Old 4 weeks ago
  #30
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Quote:
Originally Posted by king2070lplaya View Post
Maybe I am misreading, and if so that is my fault, but there often seems to be a strong negative reaction to techniques demonstrated in posts like this, that such techniques “don’t work”, or don’t work well, or are inferior to other, better techniques, based on what I would describe as a shallow theoretical understanding of mic technique. I don’t much see the point in those responses, as they do not usually help to answer the questions posed by the OP’s of what they are seeing and why one would use a setup. That’s what I’m reacting to above. If you were to ask “what’s a good mayonnaise-based sauce for French fries?”, and received the answer that “mayonnaise is gross and you should prefer ketchup outright for X or Y objective reason”, well that’s not very helpful, is it?

(Edit to say that I looked this album up, it is engineered by Jonathan Stokes, who learned and worked under the greats at Decca in the 80s and 90s, and has a great many credits to his name. His use of this technique can be taken as a ringing endorsement of its effectiveness.)
It would be very naive or arrogant to pronounce that an example like this one, where major talent meets major label and studio investment meets top engineering practice was simply wrong or intrinsically flawed. Clearly not the case.

However on first appearance there are aspects that either provoke a quizzical look or ring warning bells about phase cancellations etc....and there's nothing wrong with exchanges of views on why this clearly isn't so !

Maybe this sort of 3 mic vocal spot method is a relatively new innovation, compared with the older Decca practice of a single voice spot, and thus it's clearly of interest to trace the genesis of such new innovations.

We all know there are often several possible approaches to miking a particular musical event....we discuss the variables, preferences, pros/cons and drawbacks of these often...but simple uncritical acceptance of methodology doesn't advance art or science helpfully either.

As Tony Faulkner often repeats "the maths may not be elegant, or perhaps it's even theoretically incorrect, but if it sounds right....then that's all that counts"

This forum is a broad church, encompassing adherents to many recording approaches, and it's all the stronger for that diversity
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