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Hey all,

I've been digging this new forum Index! Thanks for all the great info so far, and keep it up!

Was just wondering what some of the fave mics and Micing techniqus are for recording solo classical guitar.

Also, I will be doing another session with classicall guitar and male voice. What is a good way to deal with this? The vocalist is considerably louder than the guitarist in many passages. How does one set up in order to not have the guitar mics overwhelmed by the vocalist?. Also, the character of this music is such that the vocalist should be miced up close(ie not classical).

Mics that I currently own:(I would like to settle down on a mic setup that is outstanding for classical guitar. So, I'm willing to buy something new if these don't cut it)

Shure: ksm-44
Soundelux: U195
AT 4051 pair
km-184
Oktava: mc012

Pres: DAV BG1
Peavey VMP2(too colored obviously)
MOtu 896HD built in pres

Much thanks in advance to all!

Comments

FifthCircle Wed, 01/05/2005 - 17:43

I use a mid-side pickup more often than just about anything else for classical guitar recording. Lately, I've done a couple gigs with a Royer SF-24 and I'm getting probably the best classical guitar sound I've ever gotten. Normally, I use an AKG 426 or perhaps an AKG C-34. I've also used Schoeps MK4 and MK3 (?) capsules in a combination to make a M-S mic with good luck.

If you can control the floor reflections, I've done an "ORTF" type pickup using my B&K 4006s on a stereo bar and it seems to work quite well- probably because they space proportionally to the size of the sound source. In concert work, I will usually mic from underneath the instrument to keep the mics out of the visual sightlines of the audience.

If they absolutely cannot see microphones, the Schoeps and Sanken boundary mics can work well.

--Ben

Cucco Fri, 01/07/2005 - 11:12

I'm starting to notice a trend here - Ben's a M-S Guy and I'm an A-B guy. Oh well, they both work really well.

I just did a recording of the McLean Symphony here in Northern VA with classical guitarist Gray Snead. There were so many mics covering this guy, it was almost impossible to see him from the audience. They weren't all mine - I had a Schoeps CMC6 Mk 21 and an Oktava tube mic on the same stand. The tube was oriented pointing from the base of the instrument upwards towards the tone hole, but several inches back. The Schoeps was angled similarly, but aiming towards the base of the neck (a little higher than the base). All the other mics were - 2 TLM 103s placed there by the "other" recording guy (he's the orchestra's regular 'free' recordist - I was hired by the guitarist) and a Senn dynamic mic for the house engineer. All in all, it looked like we were about to launch the poor guy into space!

BTW...I swear, I'll be posting some samples on my web-site soon. I used to have them there, but my site crashed and I had to rebuild everything.

Now, all that being said, you don't have any of the gear I mentioned and it doesn't really answer your question all that much.

Any of your pres will do the trick - the Peavey isn't unusable, just realize its colorations and use them to your advantage.

Personally, for classical guitar, I would think you could successfully use any combination of the mics you have listed. I would lean towards the ATs or the Oktavas for the neck and perhaps the Soundelux for the body.

Of course, you could do SDCs on the guitar in its entirety and get great results. (the AT pair.)

I think, if you mic the guitar relatively close and the vocalist relatively close, you should be okay - not too much uncontrollable bleed.

BTW...you mentioned this is a session? not a concert right? If it's a session, play around with musician placement. Don't aggrevate the musicians, but by all means, see if they're willing to move around a bit. If it's a concert, good luck! No matter what you try to do, someone or something will almost always mess it up. :evil: (not ruin it, but for example, even though you told the vocalist a thousand times not to "eat" the condenser mic, they will, etc.)

Good luck!

J...

FifthCircle Fri, 01/07/2005 - 11:20

Cucco wrote: I'm starting to notice a trend here - Ben's a M-S Guy and I'm an A-B guy. Oh well, they both work really well.

Nah- I use what works for a given situation. For solo piano and guitar, I find that M-S can work quite well. Occasionally, I'll use it for an orchestra, too... I probably use Blumlein more than anything- the rear lobes get in the way of the sound for solo guitar, though (floor reflections most often).

In many cases, I don't like mid-side because I don't like the out of phase nature of the side microphone.

--Ben

anonymous Fri, 01/07/2005 - 13:18

The micpre choice is easy-- your Broadhurst gardens is tops. For mics, the only one I have experience with is the KM184, which I would avoid if possible, but I do not know how this compares with your others.

I reach first for omnis (as Ben described) for this sort of thing. But I don't think you have any, so plan B:

Take the time to try different things, and experiment with a gobo to block the voice from your guitar mics-- something like 3/4 ply with lambswool on both sides (not unlike a Jecklin disc).

IMHO avoiding brittle and bright is the goal.

And if possible find a resonant room that isn't too huge to record in---late at night!

Rich

anonymous Fri, 01/07/2005 - 23:56

Hey,

Thanks for all the great thoughts and ideas. I have done quite a bit with the m/s setup using the shure with a sdc. They come out quite nice much of the time. I like having the control over the stereo image with that setup.

One interesting point...I often find that I am at first excited by the width that is possible with the m/s setup, and then find that it is not very natural sounding. As I adjust it, I find that I go closer and closer to mono to get it sounding natural(in terms of instrument tone). Often, I found that I need it to be nearly completely folded to mono for the right tone. Of course, at that point, the whole stereo image is a lost cause. :roll:

I'm assuming that this means that some phase problems are happening. Is this what you were referring to Ben?

By the way Ben, when were you at USC? I went there as well(for my classical guitar degree) Yes, I am the guitarist to be recorded as well. :oops:

I have to say that I would love to try some omni recrdings with the guitar. Which omnis are your faves for that Sonarec?

Thanks again to all!

O

FifthCircle Sat, 01/08/2005 - 00:05

Not exactly...

The phase thing I was talking about is because to decode Mid Side, you split the side (a fig-8) and invert phase. The matrix then makes your Left-right signal. If you listen to your sides alone, you hear a signal that is exactly 180 degrees out of phase with itself. When summed, you loose it completely (hence the perfect mono compatability). What that also means, though, is that if a lot of ambient information is coming in through the side mic, you will hear things out of phase. I notice it most of all when the applause starts in a concert. All of a sudden, there is much more side information versus the middle and the phase can sound strange...

Ahh... Another that suffered through USC. I did my Master's there in clarinet performance, actually. Graduated in '99 with it. I still do a lot of recording around there (a lot of recitals and I record the choirs and composition departmental stuff there...).

--Ben

Cucco Sat, 01/08/2005 - 06:29

ozmorphasis:

I'll jump in and answer your question about the omni mics. Being an omni freak, I would easily lean towards the Schoeps in this case. I would say, that in most cases, the Schoeps are my safety mics - only because they are genuinely neutral. You may even try their MK21 - wide cardioid. These have that omni sound with just a little bit more rejection of off axis high frequencies.

J...

JoeH Sat, 01/08/2005 - 09:47

Interesting tale about all those mics, Jeremy! (I guess no one dared bring up the idea of a splitter, or giving the house sound guy a feed from either of your boards?)

I've been there as well, when somehow, some way, you're elbow to elbow with ANOTHER guy (often a hobbyist doing it for fun/experience) doing it for Free (ie: Undercutting) with an orchestra or ensemble. Nothing says: "Hey, this is really easy and cheap to do" better than NOT charging someone. Oiy....

I have a baroque group that uses a "Freebie" guy on Fridays, and hires us to do their Saturday & Sunday concerts. (all three happen in separate venues, so it's a moving target, in many ways.) The weird parts happen when we get some of his recordings to compile for a grant or a broadcast. THEN I have the unpleasant task of explaining to them why his stuff doesn't match ours, and why the sound is inconsistent.

I'm completely uninformed about Octava mics. I've avoided them early on because I heard it was tough to find good, consistent ones (myth or ?) and they seemed to be a Guitar-Center/Sam Ash favorite for a while there. I'm probably looking at the wrong models as well.....any thoughts on these?

Cucco Sat, 01/08/2005 - 16:40

Yep, wayyyyy too many mics. I told the other guys that they could patch out of my board, but neither of them wanted to do it.

As for the Oktavas - yes, they can suck the big one. However, for the money, they can be amazing tools. What I do is I wait for GC to run them on sale at ridiculous prices and then go in and buy a few. (For example, I got the tube mic for $99, on sale from $699! Also, 5 MC012s for $200.) They let me play with all the ones they have in stock til I find the ones I like. Then I buy those.

Do they compare with the big guys, in some ways yes, in many ways, no. But, they are cheap and I would still use them over a Neumann KM184!

J...

DavidSpearritt Sun, 01/09/2005 - 05:43

The thing with classical guitar is getting a solid stereo image, this is the most important acoustic feature to get right IMHO. So omnis and AB are right out.

Blumlein and MS Blumlein are the only way to record it. I own and have heard so many CD's of solo classical guitar ( I am a lapsed CG'ist) where the image is all over the place, cardioid near the bridge omni pair somwhere else, oh please. Listen to some David Russell CD's and you will hear how not to record the CG, even though the playing is great.

The SF24 has got to be the best shot at this instrument, bass sound power is not strong from a CG so the argument for omnis makes little sense.

I want a solid stereo image of the guitar between the loudspeakers, so that the speakers do their disappearing act, Blumlein is the secret.

Cucco Sun, 01/09/2005 - 06:35

Hey David, welcome to the forum!

In general, I disagree with a lot of what you've said. You can get a perfectly viable stereo field with omnis AB or a mix of omni/cardiod. One simply has to be careful how the guitar is panned. I frequently try to avoid using the phrases "only way to record it," as many of us here have agreed there are imany different ways to skin a cat.

The fact that the bass is not that prevalant from the CG has little to do with my choice for omnis. They certainly don't emphasize bass, but record it flat as it is present in the sound field.

Just curious, would you feel the same - Blumlein only - for guitar and orchestra? What purpose to the rear lobes of the fig 8 serve? I would assume your overheads would pick up the necessary ambience. Therefore, all you would need in that case is XY.

Just some thoughts.

J...

anonymous Sun, 01/09/2005 - 12:07

David,

If you are feeling experimental, just TRY omnis about 19inches apart at various distances and angles. It seems to me that while you certainly want a realistic impression of a guitar, you don't need to have such imaging as to be able to shut your eyes and know what fret he is on.

Your point about bass is on target, which argues in favor of omnis. The proximity from the SF12 or 24 won't be much help unless you are so close that the quitar image is from tweeter to tweeter. That is a scary thought, IMHO.

Rich

DavidSpearritt Sun, 01/09/2005 - 12:30

Sonarerec wrote: It seems to me that while you certainly want a realistic impression of a guitar, you don't need to have such imaging as to be able to shut your eyes and know what fret he is on.

But this is precisely what you do want. It is the most exciting stimulus while listening to a guitar. The player is reproduced in your room between the loudspeakers while they dissappear.

The guitar has all sorts of nuances to do with what string the note is played on, often the third string is used for emphasis on melody, the fifth string has a particular resonance above the 5th fret, vibrato and other string bends are sometimes very subtle etc etc, and accurate imaging is almost more important that tonal accuracy, in recording these subtleties.

Spaced omnis are incapable of doing this. Also most recordings of the guitar, like the piano are recorded too close. The table of the guitar is like the soundboard of the piano, one needs to be at least one characteristic dimension away from it, ie at least 1m away.

I have made many recordings of the CG, of both myself and others playing, I test new mics this way as well. But it is a personal thing and this is my opinion only.

There are so many squandered opportunities in commercial CG recordings because engineers and producers fail to understand the acoustics of this instrument.

I recommend listening to any of the Opus3 (Jan Erik Persson) guitar recordings, this guy knows how to record the guitar. (IMHO) :)

DavidSpearritt Sun, 01/09/2005 - 12:43

Just to add, that I love spaced omnis for certain things, mainly very large sound sources, ie orchestra or choir, but do not like them for small sources, like the solo guitar or chamber music, where I hear the following problems in abundance:

1. Comb filtering (oboe and clarinet its so obvious, but guitar as well)
2. Image inaccuracy
3. Hole in the middle

These things far outweigh the wonderful tonal accuracy down low, as I said, often there is no energy down there, from a guitar, so whats the point of recording nothing.

Cucco Sun, 01/09/2005 - 18:37

David,

I have to vehemently disagree with many of the comments you make here about the inadequecies of spaced omni.

1. "Hole in the middle" syndrom is from spacing the omnis too wide or angling them away from each other.
2. Image accuracy - strongly tied to number 1 above, has to do with the positioning of mics. As I mentioned in a different thread, "omni-directional" is a misnomer. Only in the low frequencies do omnis act truly omni. Otherwise, in the frequencies most easily detectable to the human ear, omnis are quite directional. The problem with imaging on omnis is a myth most often perpetuated by those unwilling to experiment with them.
3. Low frequency absence on CG. On the few recordings I've done of classical guitar, I have had usable, substantive tones as low as 40 hZ. I wouldn't say "there is no energy down there."

I will strongly agree with you on the point you make about those who record instruments too closely. While sometimes essential to get up close on an instrument, I often find myself re-evaluating a set-up and thinking - "did I put those too close?"

Just some opinions...

J...

anonymous Sun, 01/09/2005 - 21:20

What do you think of Steve Morses classical recordings , with his trick of panning each string alternating hard left and right? It sounds gigantic. I've read his classical guitar ( a $6000 handmade Buscarino) has a special pickup with 6 seperate outputs , 1 for each string. Is there a way to simulate that effect or a similar pickup? I love his classical guitar sound.

anonymous Sun, 01/09/2005 - 23:15

DavidSpearritt wrote: I hear the following problems in abundance:

1. Comb filtering (oboe and clarinet its so obvious, but guitar as well)
2. Image inaccuracy
3. Hole in the middle

If these things normally happen to you, then there is something amiss other than the choice of mics. Go to http://www.dpamicrophones.com/ and click on Microphone University and you may find that the issues are related to techniques.

You are certainly free to choose another path, but to me the items above indicate too much of a space between the microphones or an out-of-phase cable. I would not consider anything wider than 50cm unless you are in King's College Cambrige (or similar).

Rich

DavidSpearritt Mon, 01/10/2005 - 04:05

Its good to have these discussions, but I am a bit taken aback by the quoting of microphone university papers (no specifics) or that its the technique that maybe wrong.

I have 18 years of real studio and broadcast recording experience with spaced omnis, I have used them regularly for all that time. We have a matched prs of B&K 4003's, Schoeps MK2, Neumann KM130 AKG 414's etc and have used them hundreds of times, on chamber music, choral, orchestral, solo instruments.

We beg to differ on the results, but its not technique thats amiss, its plain old physics. Spaced mics (I typically use 400mm as the B&K bar is calibrated in), produce phase differences to get an approximate image, this produces the faults described above that I can clearly hear.

I, and many other engineers, prefer coincident techniques that eliminate these problems for dimensionally small sound sources. They introduce other problems but these are less offensive to my ear in a well controlled hall. We have one of the finest halls in the southern hemisphere to test in, the magnificent Conservatorium Theatre, designed by Nagata Acoustics.
http://www.nagata.co.jp/gyoseki/brisbane-e.htm

The main benefit of omnis is the extended low frequency response, not much else. We tend to only use omnis or fig8's as these are the only two types of mics in existance, ie pressure and pressure difference, they produce the most neutral results. All other mics are hybrids of these and suffer off axis problems to do with the hybrid arrangements.

I can list many recordings of solo CG that are just one big amorphous swimming mess (omnis) and I don't like it, its not how the instrument appears when heard live so its not a good recording in my definition.

If you want to wire strings to each speaker then so be it, but that is not an acoustic recording.

Last time I looked/listened, the lowest string on a CG is a low E, sometimes a low D. The E is E1 or 82.4Hz and the D is D1 or 73.4 Hz, so where the 40Hz is coming from beats me.

Good discussion though. :D
Cheers

Cucco Mon, 01/10/2005 - 09:49

Believe me Dave, we all respect eachothers work and experience here. Any statements of opinion on this forum are not to be taken as personal attacks against that. However, it's clear that many of us differ on opinion and our interpretation of the facts.

As I've stated numerous times on this and other forums, I'm a big fan of omnis (spaced and coincident - yes, this does work - not as clearly as cardioid, but nonetheless, it's there.)

To state that essentially the only advantage to omni is low frequency is a bit short-sighted and many, including myself, would strongly disagree.

Also, it is true that a true omni mic replicates a stereo image based solely on the differences in time/phase alignment. However, to date, there has never been a "true" omni ever created. And if it were, you wouldn't be able to put the mic on a tall stand for fear of damaging the capsule due to the minute changes in air pressure.

That being said, direction is very important in even the best omnis.

Also, as far as the 40 Hz, if the fundamental pitch is approximately 80Hz (which you are absolutely correct there), there are strong overtones emitted often exactly 1 octave lower. These overtones (or undertones euphamistically speaking) are essential to the correct production of the tone of the instrument.

J...

anonymous Mon, 01/10/2005 - 10:05

Please do not take any comments personally, as I do NOT mean them in an insulting manner! I clearly don't mind certain things about guitar recordings that seem to be a problem for you. One statement does beg explanation:

DavidSpearritt wrote: Last time I looked/listened, the lowest string on a CG is a low E, sometimes a low D. The E is E1 or 82.4Hz and the D is D1 or 73.4 Hz, so where the 40Hz is coming from beats me.

Not being a guitarist I do not know if this is even possible, but if D at 73.4Hz is played with the A above it, you WILL get a tone at 36.7Hz. These are called Helmholtz tones, and are how organ pedal stops such as a 32-ft resultant can give you a 16Hz low C by sounding 32Hz C and 48Hz G together. Phenomena such as this can be often heard in the orchestra, depending on the scoring. A famous spot (or infamous if you're in the orchestra and are going nuts with it) is the Tschaikovsky Nutcracker Overture with the horns in various intervals causing difference tones. Same principle.

Rich

DavidSpearritt Mon, 01/10/2005 - 10:23

Cucco wrote: Any statements of opinion on this forum are not to be taken as personal attacks against that. However, it's clear that many of us differ on opinion and our interpretation of the facts.

No offense was taken at all and I agree that we should disagree. But the inference was that I was doing something wrong, and this is not a good assumption.

To state that essentially the only advantage to omni is low frequency is a bit short-sighted and many, including myself, would strongly disagree.

What are the acoustically significant other advantages?

However, to date, there has never been a "true" omni ever created. And if it were, you wouldn't be able to put the mic on a tall stand for fear of damaging the capsule due to the minute changes in air pressure.

We are talking second order effects here, this is very academic.

Also, as far as the 40 Hz, if the fundamental pitch is approximately 80Hz (which you are absolutely correct there), there are strong overtones emitted often exactly 1 octave lower.

Strong? I doubt this very much. They are probably more than 10dB down if they are detectable at all, unless the guitar is broken. In rotating machinery, we used to see sub harmonics when something was loose. Also, in my reading of guitar acoustics, there is very little mention of this phenomonon. There is some info here.
Link removed

These overtones (or undertones euphamistically speaking) are essential to the correct production of the tone of the instrument.

Essential? Strong? I propose that this, again, is academic, for arguments sake, and I very much doubt they play a role as significant as you elude to, if at all.

Regards

DavidSpearritt Mon, 01/10/2005 - 10:35

Sonarerec wrote: Not being a guitarist I do not know if this is even possible, but if D at 73.4Hz is played with the A above it, you WILL get a tone at 36.7Hz. These are called Helmholtz tones, and are how organ pedal stops such as a 32-ft resultant can give you a 16Hz low C by sounding 32Hz C and 48Hz G together. Phenomena such as this can be often heard in the orchestra, depending on the scoring. A famous spot (or infamous if you're in the orchestra and are going nuts with it) is the Tschaikovsky Nutcracker Overture with the horns in various intervals causing difference tones. Same principle.

This is a "difference" tone being one frequency minus the other, well documented in theoretical physics.

But assuming the guitar strings if plucked in a certain combination produced this difference tone, the guitar table or top plate has to radiate this sound. Contrary to popular belief, strings do not make sound, the wooden top does!!!

You will note from my previous reference that the fundamental modes of a guitar plate are higher around 70Hz, so it cannot re-radiate the 40Hz difference tone with any sort of efficiency (to be Strong and Essential to guitar sound) even if it was there.

I argue that this "sub harmonic" radiation from the guitar is simply not acoustically significant and is a red herring in this argument. :D

Cheers

Cucco Mon, 01/10/2005 - 16:20

DavidSpearritt wrote:
No offense was taken at all and I agree that we should disagree. But the inference was that I was doing something wrong, and this is not a good assumption.

Glad there was none taken. I don't know that I implied that you were wrong. I try to avoid making such bold statements. My overriding philosophy with acoustic music is "There's no such thing as wrong, just different."

What are the acoustically significant other advantages?

Well, there are quite a few.

First, pressure microphones are considered better at picking up the "air" or "space" between instruments better. Since they do not rely heavily on the direct radiation of sound waves on their capsule.

Second, there is much better off-axis coloration (or should I say, a better lack of coloration).

Third, lack of proximity effect. I like to think of this as more than just "lack of boominess" at close distances. At far distances, omnis maintain more of the original frequencies than any other type of directional capsule.

Fourth, the human ear picks up sound almost identically to an omni mic. It only makes sense to use a mic as close to the ear as possible. Ben will contend here that there is no mic the same as the human ear and that they all lie. I'm inclined to agree with him, but that doesn't mean I shouldn't look for what is absolutely closest.

Fifth, sixth, seventh...I don't want to write my book here; I'll publish it in hard bound later this year and I'll give all RO members 10% discount. :lol:

We are talking second order effects here, this is very academic.

Academic, yes, but still quite relevant.

Strong? I doubt this very much. They are probably more than 10dB down if they are detectable at all, unless the guitar is broken. In rotating machinery, we used to see sub harmonics when something was loose. Also, in my reading of guitar acoustics, there is very little mention of this phenomonon. There is some info here.
Link removed

You are quite right, the sound is often attenuated almost exactly 10 dB. However, an overtone which is only half the volume of the fundamental is still quite noticeable to the human ear. It may not be so strong as to be readily identifiable. However, take the tone away and there is definitely some psycho-acoustics kicking in telling you that there is something missing.

Essential? Strong? I propose that this, again, is academic, for arguments sake, and I very much doubt they play a role as significant as you elude to, if at all.

I contend that any pitch, fundamental or overtone, is critical to the accurate representation of any musical production. This is why I firmly believe that higher sampling rate is better (we won't get into the debate over Sample Rate Conversion - that's a whole different topic - one which you and I would probably agree on), analog is best, but overall the mics have to capture everything.

Cheers!

J...

Cucco Mon, 01/10/2005 - 16:31

DavidSpearritt wrote: No subwoofer used. I monitor on BM6a's and BM15a's. I have a big JBL double woofer theatre speaker that I'm thinking of using as a coffee table in the lounge, wired of course. Does that count? :D

Hey, I did that with a pair of Cerwin Vega's in college. The coolest, loudest, bassiest coffee table in the dorm! (BTW, nothing beats mono porn matrixed into dolby pro-logic over Cerwin Vega's at 200 watts each!)

How do you like the BM15A's?

I've thought very seriously about their non-powered counterparts. (as I already have much amplification.)

J...

DavidSpearritt Tue, 01/11/2005 - 01:56

This is why I firmly believe that higher sampling rate is better (we won't get into the debate over Sample Rate Conversion - that's a whole different topic - one which you and I would probably agree on) ...

Doesn't sound like it. I hold controversial, passionate views on that too. I am not a subscriber to "higher faster better" marketing FUD around these days. :D

DavidSpearritt Tue, 01/11/2005 - 02:57

Cucco wrote: First, pressure microphones are considered better at picking up the "air" or "space" between instruments better. Since they do not rely heavily on the direct radiation of sound waves on their capsule.

How, why? Fig 8 mics create better images, or better representation of where the acoustical stimulus (waves) came from, ie music or "air or space between ..." whatever that is.

Second, there is much better off-axis coloration (or should I say, a better lack of coloration).

There is nothing better off axis than a "thin in 2 dimensions" ribbon in a fig 8 mic. Much better than an omni.

Third, lack of proximity effect. I like to think of this as more than just "lack of boominess" at close distances. At far distances, omnis maintain more of the original frequencies than any other type of directional capsule.

In classical acoustic recording, we should not be in the prox effect region this is too near field. Omnis only have better bass than fig 8's further away. This has already been granted, and I am a frequent user of omni's in the outrigger distances as auxilliary mics to a coincident array. :D

Fourth, the human ear picks up sound almost identically to an omni mic. It only makes sense to use a mic as close to the ear as possible.

Unless I am mistaken, we are not talking binaural recording here, so whether a mic behaves like an ear is irrelevant. The mic signals are ultimately loudspeaker signals, ie to reproduce the sound source phantom image between the loudspeakers. They have mothing to do with ears, and everything to do with loudspeaker drivers.

Regards

Cucco Tue, 01/11/2005 - 06:41

You know, we're both speaking english, but I feel like we're talking in a different language here.

DavidSpearritt wrote:
How, why? Fig 8 mics create better images, or better representation of where the acoustical stimulus (waves) came from, ie music or "air or space between ..." whatever that is.

Where are you getting this information? Yes, they are more directional, but that doesn't mean they are better at creating a realistic sound field, just that they pick up stuff better in certain directions. "air of space between" is simply that - instead of just capturing the sounds of the notes themselves, omnis are cleaner at picking up subtleties such as distances between musicians, etc. This is due to the fact that they record the pressurisation of the air - something that compresses based on the physical environment in which it's in.

There is nothing better off axis than a "thin in 2 dimensions" ribbon in a fig 8 mic. Much better than an omni.

WHAT?! Figure 8 off axis is a null plane - how in God's name can it be better off axis than an omni, which is regarded for their clean off axis response?

In classical acoustic recording, we should not be in the prox effect region this is too near field. Omnis only have better bass than fig 8's further away. This has already been granted, and I am a frequent user of omni's in the outrigger distances as auxilliary mics to a coincident array. :D

This is a common misconception. Proximity effect, translated literally means the effect on the recorded sound based on the distance to the sound source. By no means do you have to be "near-field" to have an exhibit of proximity effect. The omni's lack of proximity effect (or substantial reduction, as there is no mic devoid of proximity effect issues) is apparent in that the bass and treble signals do not significantly degrade or enhance based on their proximity to the sound source. No other microphone can claim this. Oh, and by the way, the bass drum is usually at the back of the orchestra - I want a mic without prox effect so I can pick up this low frequency.

Unless I am mistaken, we are not talking binaural recording here, so whether a mic behaves like an ear is irrelevant. The mic signals are ultimately loudspeaker signals, ie to reproduce the sound source phantom image between the loudspeakers. They have mothing to do with ears, and everything to do with loudspeaker drivers.

Regards

The day that I think that recording, in general (not just binaural) is irrelevant to how it relates to the human ear, is the day that I retire.

I don't want my mics to pick up the way loudspeakers disperse. I want my mics to pick up an orchestra. I hope your loudspeakers and everyone elses are capable of replaying a sound somewhat reminiscent of an orchestra. SPEAKERS have nothing to do with my recordings, EARS have everything to do with it.

J...

DavidSpearritt Fri, 01/14/2005 - 15:18

At the risk of being labelled a bore, I feel compelled to clear up some confusions from this thread, mainly about microphone response. Forgive me Jeremy.

Firstly, lets deal with the confusion of directivity with "good off axis response". These are very different.

There is nothing better off axis than a "thin in 2 dimensions" ribbon in a fig 8 mic. Much better than an omni.

WHAT?! Figure 8 off axis is a null plane - how in God's name can it be better off axis than an omni, which is regarded for their clean off axis response?

Directivity in a mic refers to the change in amplitude response with angle around the capsule. In an ideal omni, 0dB is seen on axis and 0dB should be seen at 120 degrees off axis. Directivity in a fig 8 means 0dB on axis, but 10dB or whatever off axis. I was not arguing that a fig 8 has the off axis "directivity" of an omni, this is absurd.

But, usually in conversations of this type, "good off axis response" of a mic means, given the directivity, the shape of the freq response is the same at 0 degrees to 120 degrees, ie if the response curve is flat at 0 degrees and 0dB, it should also be flat at 120degrees and 10dB down. ie all frequencies are picked up at -10dB equally.

This is what is referred to as "good off axis response". Most cardioids have pretty ordinary off axis responses, while the FR curve is flat at 0deg, it is all over the place at 120deg, hence they sound terrible in a spaced pair splayed out where most of the musicians are picked up way off axis.

So, what causes the off axis response to be bad?. Diffraction around a big mic cage, a large diaphram, strange tortuous paths for the sound waves through the behind capsule slots in the mic case to make them a cardioid etc.

This is also why omnis are not omni at HF.

Now I said...

There is nothing better off axis than a "thin in 2 dimensions" ribbon in a fig 8 mic. Much better than an omni.

and the meaning was that in an SF24 for example, the ribbon is 25mm long, 1mm wide!!! and 1 micron thick. So in the plane of the mic directivity, the capsule is only 1mm wide, compare this to 16mm for a small diaphram omni. So while the Royer is a fig 8, its FR will be accurate and the same shape all the way round the capsule. Hence my comment.

Where are you getting this information? Yes, they are more directional, but that doesn't mean they are better at creating a realistic sound field, just that they pick up stuff better in certain directions. "air of space between" is simply that - instead of just capturing the sounds of the notes themselves, omnis are cleaner at picking up subtleties such as distances between musicians, etc. This is due to the fact that they record the pressurisation of the air - something that compresses based on the physical environment in which it's in.

So this comment does not make sense, because a Blumlein pair is "omnidirectional" to all the musicians or sources in the window of view. With the two capsules working together, the FR of the array is uniform for sound arriving from any direction. A mic does not know if its receiving pressure variations from the "air in between" (never though that produced much sound) or from the musicians. The Blumlein array "locates" the sound better than any other sort of array, ANY!, hence my comment about it locating the "air" better.

Sound is a "pressure variation" it is not DC pressure, so the comment about omnis responding to pressure like our ears is irrelevant. Our ears are actually fig 8 diaphrams, Jeremy, they detect and measure pressure differences between the front of the diaphram (eardrum) and the rear of the diaphram, (middle ear), the eustation tube is the rear air path.

The day that I think that recording, in general (not just binaural) is irrelevant to how it relates to the human ear, is the day that I retire.

I don't want my mics to pick up the way loudspeakers disperse. I want my mics to pick up an orchestra. I hope your loudspeakers and everyone elses are capable of replaying a sound somewhat reminiscent of an orchestra. SPEAKERS have nothing to do with my recordings, EARS have everything to do with it.

No, no no. The two microphones in a stereo array are loudspeaker source signals, nothing else. They are not ears. The number of times I hear people talk about mics needing to be ear spaced etc is comical. They form two loudspeaker signals to drive the loudspeakers into creating a phantom image between the loudspeakers to represent as close a replica to the original source field.

When you record a string quartet, you want the quartet to be sitting between your speakers when you play back. The two mic signals need to measure the differences in cues so that the loudspeakers can render these differences to re-locate the phantom image.

So omni devotees rely on time of arrival differences to make the left mic receive sound before the right to force the L loudspeaker to sound before the R. The listener then thinks the sound source is on the left, which it maybe with omnis. :)

A Blumlein array measure sound level difference between sources on the left or right, which it so sharply measures and forces the same level differences in the speaker replay and hence force the listener to locate the source to the left between the speakers.

There are no ears involved in any of this except when listening to your loudspeakers. You are trying to listen to exactly the same cues generated by the LS as by the original musicians. Mics are not picking up sound anything like speakers disperse they are signal generators.

Hope this clears up where I am coming from?

Cheers

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