Omnidirectional microphones and A-B Stereo are often the preferred choice when the distance between microphone and the sound source is large.eehhh? ???
just when I thought to have understood that spaced omnis are a prefered option if recording from minimal distance to the sound source, e.g. when possible to place them on stage, I ran across this:QuoteOmnidirectional microphones and A-B Stereo are often the preferred choice when the distance between microphone and the sound source is large.eehhh? ???
quote taken from: http://www.dpamicrophones.com/ (http://www.dpamicrophones.com/) /Microphone University/Stereo Techniques/A-B stereo
but for amp'ed music I would personally never put a set of mics on stage, all you will get is a loud Guitar amp and cymbals, and if your real lucky a wee bit of vocal.
Just remember the two to one ratio, that Omni mics should be twice the distance apart as they are from the source.
a j-disc will be more consistent than spaced omnis. (there, I said it).
a j-disc will be more consistent than spaced omnis. (there, I said it).
Teddy was fluffing Josephson C617s with 45cm (18") separation, I hve been using the C617s with various J-disky baffles. I hope to try the spaced omnis next month, any other reports of good results with that small a separation?
Jeff
but for amp'ed music I would personally never put a set of mics on stage, all you will get is a loud Guitar amp and cymbals, and if your real lucky a wee bit of vocal.
While my experience mirrors Chris's with regards to weak vocals, I've not had the same experience getting only loud guitar amp and cymbals.Just remember the two to one ratio, that Omni mics should be twice the distance apart as they are from the source.
I suspect this ratio originated for unamplified recording for orchestras and such, I'm not convinced it applies to on-stage recording of amplified performances. I've found my mic placement depends on the layout of the band on stage, don't pay any attention to the 2:1 ratio, and have enjoyed the results. In many cases, I couldn't physically use the 2:1 ratio even if I wanted to due to space restrictions.
Just remember the two to one ratio, that Omni mics should be twice the distance apart as they are from the source.
Just remember the two to one ratio, that Omni mics should be twice the distance apart as they are from the source.
That rule basically tells you to use AB spaced omnis only close to the sound source. If you try to follow this rule at any significant distance, you'll have your mics out of the building, or if it's outdoors, you'll have a huge hole-in-the-center effect.
A more realistic rule might be the one from the New Stereo Soundbook that references keeping the spaced omnis apart by between 1/3 and 1/2 the width of the soundstage (ie: the PA in most cases).
- Jason
does anyone have a good example of the 'hole in the middle' effect? I have an idea of what I am listening for, but I'm curious if I'm listening for the right things.
actually it is 3:1, not 2:1, Chris.Just remember the two to one ratio, that Omni mics should be twice the distance apart as they are from the source.
That rule basically tells you to use AB spaced omnis only close to the sound source. If you try to follow this rule at any significant distance, you'll have your mics out of the building, or if it's outdoors, you'll have a huge hole-in-the-center effect.
A more realistic rule might be the one from the New Stereo Soundbook that references keeping the spaced omnis apart by between 1/3 and 1/2 the width of the soundstage (ie: the PA in most cases).
- Jason
Hey I said 3:1 not 2:1 :wink2:actually it is 3:1, not 2:1, Chris.Just remember the two to one ratio, that Omni mics should be twice the distance apart as they are from the source.
That rule basically tells you to use AB spaced omnis only close to the sound source. If you try to follow this rule at any significant distance, you'll have your mics out of the building, or if it's outdoors, you'll have a huge hole-in-the-center effect.
A more realistic rule might be the one from the New Stereo Soundbook that references keeping the spaced omnis apart by between 1/3 and 1/2 the width of the soundstage (ie: the PA in most cases).
- Jason
Just remember the two to one ratio:P
Hey I said 3:1 not 2:1 :wink2:actually it is 3:1, not 2:1, Chris.Just remember the two to one ratio, that Omni mics should be twice the distance apart as they are from the source.
That rule basically tells you to use AB spaced omnis only close to the sound source. If you try to follow this rule at any significant distance, you'll have your mics out of the building, or if it's outdoors, you'll have a huge hole-in-the-center effect.
A more realistic rule might be the one from the New Stereo Soundbook that references keeping the spaced omnis apart by between 1/3 and 1/2 the width of the soundstage (ie: the PA in most cases).
- JasonQuote from: Chris"amnesia"ChurchJust remember the two to one ratio:P
Aaah, I see, the much misunderstood 3:1 rule.
And now, sorry for the emphasis.
The rule of thumb is ONLY of any use when you use two mics to record two DIFFERENT sound sources and want the two sources to be SEPARATED. So if you want one channel to have the lead singer and one to have the backup singer it is applicable. If then the singers are each one meter away from his/her mic, then the mics should be at least three meters from each other. Then each mic will basically only have one singer, allowing you to mix and match without much problem with phase issues and bleed between the mics. As with any rule of thumb it certainly does not work in every circumstance. It is a useful starting point for mulitmicing things in the studio or on the stage.
It has ABSOLUTET NO RELEVANCE for the distance between the two mics that make up a stereo pair. Here we want both mics to capture every source to some degree. The arrival time and volume differences are queues for our brain to recreate the stereophonic landscape. How to setup the mics is ruled by what stereo image you get, and then both mics need to get at least part of the picture, exactly as your ears.
Once more, sorry for shouting -- this seems to be a very common misconception.
Gunnar
Aaah, I see, the much misunderstood 3:1 rule.
And now, sorry for the emphasis.
The rule of thumb is ONLY of any use when you use two mics to record two DIFFERENT sound sources and want the two sources to be SEPARATED. So if you want one channel to have the lead singer and one to have the backup singer it is applicable. If then the singers are each one meter away from his/her mic, then the mics should be at least three meters from each other. Then each mic will basically only have one singer, allowing you to mix and match without much problem with phase issues and bleed between the mics. As with any rule of thumb it certainly does not work in every circumstance. It is a useful starting point for mulitmicing things in the studio or on the stage.
It has ABSOLUTET NO RELEVANCE for the distance between the two mics that make up a stereo pair. Here we want both mics to capture every source to some degree. The arrival time and volume differences are queues for our brain to recreate the stereophonic landscape. How to setup the mics is ruled by what stereo image you get, and then both mics need to get at least part of the picture, exactly as your ears.
Once more, sorry for shouting -- this seems to be a very common misconception.
Gunnar
Actually RESPECTFULLY, you have it backwards phase cancellation happens when two mics pick up the same source at the same exact time and amplitude and frequency. The polar patterns overlap making this happen. This normally happens at one frequency like for example if I had two Omni mics on a single singer and he or she was hot at 2.5k I would need to apply the three * to one ratio to avoid phase cancellation and the peek frequency or dominant frequency.
Your scenario of the rule needing to be applied with two different sources would be almost impossible to get any kind of phase problem. Hence the need to space mics with such open polar patterns (OMNI) in the first place. This is the reason why you never see a true stereo one point Omni mic; it would be a phase cancellation nightmare.Aaah, I see, the much misunderstood 3:1 rule.
And now, sorry for the emphasis.
The rule of thumb is ONLY of any use when you use two mics to record two DIFFERENT sound sources and want the two sources to be SEPARATED. So if you want one channel to have the lead singer and one to have the backup singer it is applicable. If then the singers are each one meter away from his/her mic, then the mics should be at least three meters from each other. Then each mic will basically only have one singer, allowing you to mix and match without much problem with phase issues and bleed between the mics. As with any rule of thumb it certainly does not work in every circumstance. It is a useful starting point for mulitmicing things in the studio or on the stage.
It has ABSOLUTET NO RELEVANCE for the distance between the two mics that make up a stereo pair. Here we want both mics to capture every source to some degree. The arrival time and volume differences are queues for our brain to recreate the stereophonic landscape. How to setup the mics is ruled by what stereo image you get, and then both mics need to get at least part of the picture, exactly as your ears.
Once more, sorry for shouting -- this seems to be a very common misconception.
Gunnar
Actually RESPECTFULLY, you have it backwards phase cancellation happens when two mics pick up the same source at the same exact time and amplitude and frequency. The polar patterns overlap making this happen. This normally happens at one frequency like for example if I had two Omni mics on a single singer and he or she was hot at 2.5k I would need to apply the three * to one ratio to avoid phase cancellation and the peek frequency or dominant frequency.
Your scenario of the rule needing to be applied with two different sources would be almost impossible to get any kind of phase problem. Hence the need to space mics with such open polar patterns (OMNI) in the first place. This is the reason why you never see a true stereo one point Omni mic; it would be a phase cancellation nightmare.Aaah, I see, the much misunderstood 3:1 rule.
And now, sorry for the emphasis.
The rule of thumb is ONLY of any use when you use two mics to record two DIFFERENT sound sources and want the two sources to be SEPARATED. So if you want one channel to have the lead singer and one to have the backup singer it is applicable. If then the singers are each one meter away from his/her mic, then the mics should be at least three meters from each other. Then each mic will basically only have one singer, allowing you to mix and match without much problem with phase issues and bleed between the mics. As with any rule of thumb it certainly does not work in every circumstance. It is a useful starting point for mulitmicing things in the studio or on the stage.
It has ABSOLUTET NO RELEVANCE for the distance between the two mics that make up a stereo pair. Here we want both mics to capture every source to some degree. The arrival time and volume differences are queues for our brain to recreate the stereophonic landscape. How to setup the mics is ruled by what stereo image you get, and then both mics need to get at least part of the picture, exactly as your ears.
Once more, sorry for shouting -- this seems to be a very common misconception.
Gunnar
Sorry Chris, but Gunnar is correct. The 3:1 rule is for multiple mics on separate sources. it is a multi-miking rule and does not apply to a single stereo pair. You are correct in noting that comb filtering is caused by the interference pattern of a single source, picked up by two mics and then summed again (either electronically or in air). The 3:1 rule works by getting each source/mic pair far enough away from the next that any inevital bleed is or or less inconsequential for phase issues. The rule has nothing to do with polar patterns other than more discriminating patterns can, by attenuation, help to reduce bleed and limit the comb filtering that the 3:1 rule aims to achive using distance. The different path lengths between the source and the 3:1 separated mics proivides both attenuation and phase differences between the signals of all the mics that are picking up that souce, both intentionally (mic on that source) and unintentionally (bleed from other mics).
It is physically impossible to apply the 3:1 rule to stereo micing, follow me here:
For stereo miking where some part of the source (say, the center of the stage) is equidistant from each mic, you cannot have more than a 2:1 ratio of source to mic vs. mic to mic distance. The only geometry that would acheive a 2:1 ratio would be to put the mics in a line with the source on the midpoint of that line, centered between the mics. As soon as you move the source away from the line the ratio drops. An equilateral triangle of source and mics would have a 1:1 ratio.
You are 100% incorrect The 3:1 rule does exist argue your point with GEFELL one of the most respected names in audio.
I have been a sound engineer for 20 years I know my mic techniques and not because I read them from a book because I have used them.
Chris Church
Here is the url for the info I have posted. http://www.gefell-mics.com/stereo_mic_techniques.htm
Wide stereo
Set-up: Two directional or omnidirectional spread using the 3:1 rule
Primary use: STEREO RECORDING OF ENSEMBLES AND ORCHESTRA'S
Stereo image: EXCELLENT
Center image: OKBest for: Working with the mid to far field
Advantage: Better stereo imaging
Notes:
The wide stereo employs a 3:1 rule whereby the distance between mics is 3 times greater than the distance of the source. For large orchestra, an additional center mic is often used. This provides better stereo imaging but does not make for good mono compatibility.Actually RESPECTFULLY, you have it backwards phase cancellation happens when two mics pick up the same source at the same exact time and amplitude and frequency. The polar patterns overlap making this happen. This normally happens at one frequency like for example if I had two Omni mics on a single singer and he or she was hot at 2.5k I would need to apply the three * to one ratio to avoid phase cancellation and the peek frequency or dominant frequency.
Your scenario of the rule needing to be applied with two different sources would be almost impossible to get any kind of phase problem. Hence the need to space mics with such open polar patterns (OMNI) in the first place. This is the reason why you never see a true stereo one point Omni mic; it would be a phase cancellation nightmare.Aaah, I see, the much misunderstood 3:1 rule.
And now, sorry for the emphasis.
The rule of thumb is ONLY of any use when you use two mics to record two DIFFERENT sound sources and want the two sources to be SEPARATED. So if you want one channel to have the lead singer and one to have the backup singer it is applicable. If then the singers are each one meter away from his/her mic, then the mics should be at least three meters from each other. Then each mic will basically only have one singer, allowing you to mix and match without much problem with phase issues and bleed between the mics. As with any rule of thumb it certainly does not work in every circumstance. It is a useful starting point for mulitmicing things in the studio or on the stage.
It has ABSOLUTET NO RELEVANCE for the distance between the two mics that make up a stereo pair. Here we want both mics to capture every source to some degree. The arrival time and volume differences are queues for our brain to recreate the stereophonic landscape. How to setup the mics is ruled by what stereo image you get, and then both mics need to get at least part of the picture, exactly as your ears.
Once more, sorry for shouting -- this seems to be a very common misconception.
Gunnar
Sorry Chris, but Gunnar is correct. The 3:1 rule is for multiple mics on separate sources. it is a multi-miking rule and does not apply to a single stereo pair. You are correct in noting that comb filtering is caused by the interference pattern of a single source, picked up by two mics and then summed again (either electronically or in air). The 3:1 rule works by getting each source/mic pair far enough away from the next that any inevital bleed is or or less inconsequential for phase issues. The rule has nothing to do with polar patterns other than more discriminating patterns can, by attenuation, help to reduce bleed and limit the comb filtering that the 3:1 rule aims to achive using distance. The different path lengths between the source and the 3:1 separated mics proivides both attenuation and phase differences between the signals of all the mics that are picking up that souce, both intentionally (mic on that source) and unintentionally (bleed from other mics).
It is physically impossible to apply the 3:1 rule to stereo micing, follow me here:
For stereo miking where some part of the source (say, the center of the stage) is equidistant from each mic, you cannot have more than a 2:1 ratio of source to mic vs. mic to mic distance. The only geometry that would acheive a 2:1 ratio would be to put the mics in a line with the source on the midpoint of that line, centered between the mics. As soon as you move the source away from the line the ratio drops. An equilateral triangle of source and mics would have a 1:1 ratio.
Maybe one of you omni gurus can answer a question:
DPA offers various "grids" to place in front of their omnis to alter the response of the microphone. For example, they have a diffuse-field grid that raises the response above 15 kHz when recording farther away. What's up with that? Can this be done for other microphones? How does this work? I think it would be great to have that option available on any omni, to tilt it's response up a bit when you run them farther back than you would like.
Will those balls work with just any omni? That is, if you can fine one to fit the diameter of your mic?
I really like the idea, I just don't understand it that well. :-\ Just by the looks of it, I'd tend to think the ball would attenuate any sound coming from the front of the capsule ???
looks like a $40 raquetball to me!Maybe one of you omni gurus can answer a question:
DPA offers various "grids" to place in front of their omnis to alter the response of the microphone. For example, they have a diffuse-field grid that raises the response above 15 kHz when recording farther away. What's up with that? Can this be done for other microphones? How does this work? I think it would be great to have that option available on any omni, to tilt it's response up a bit when you run them farther back than you would like.
it is simply to offset the HF loss at longer distances. It works by way of Vents, changing the way the signal interacts with the diaphragm. The grids are not the only accessory, for the high end omnis like the 4006 and the ilk, there are also pressure balls that go around the head of the mic to boost on axis sources and attenuate off axis to give better "presence" and clarity to the recordings. The catalyst for the production of the pressure balls was I think an attempt by DPA to capture some of the directivity that the Neumann m50 omnis had. (the m50s were used by Decca for many years, and are considered the de facto standard for Decca Tree Micing..) Peter Drefahl makes similar attachments for schoeps omnis, and with the DPA 4060/4061, you could remove the grille and get a flatter response...it can be done with any mic...just a matter of physics and the manufacturer or user doing their homework to develop a solution.
(http://www.dpamicrophones.com/Images/DM00866.jpg) <<<<these come in 30, 40 and 50mm...the 50mm are what I own.
... with a hole in it...
what are they made of teddy? are they rubber or hard plastic?... with a hole in it...
Yeah, I wouldnt (and didnt) pay 100 bucks for it. I paid about 110 for all 3 of mine.
what are they made of teddy? are they rubber or hard plastic?... with a hole in it...
Yeah, I wouldnt (and didnt) pay 100 bucks for it. I paid about 110 for all 3 of mine.
Matt
Will those balls work with just any omni? That is, if you can fine one to fit the diameter of your mic?
I really like the idea, I just don't understand it that well. :-\ Just by the looks of it, I'd tend to think the ball would attenuate any sound coming from the front of the capsule ???
I would say so, yes. The balls use diffractions on the surface to modify the sound field around the diaphragm. the attenuation is off axis at sources above 1khz, and on axis, the lower frequencies are boosted.
Think $100 is bad for the raquetball? How about $120 for a plastic nose cone (http://www.sweetwater.com/store/detail/UA0777/)?looks like a $120 prosthetic device to me!
(http://www.sweetwater.com/images/items/UA0777.jpg)
You are 100% incorrect The 3:1 rule does exist argue your point with GEFELL one of the most respected names in audio.
I have been a sound engineer for 20 years I know my mic techniques and not because I read them from a book because I have used them. This rule can be applyed to close micing and to distant micing BUT it is only a guidline I was only trying to say that this rule dose exist and it is used sometimes. The fact that someone says this rule does not exist does not make it so. Furthermore this rule does not always have to be used it depends on your situation.
Chris Church
Here is the url for the info I have posted. http://www.gefell-mics.com/stereo_mic_techniques.htm
Wide stereo
Set-up: Two directional or omnidirectional spread using the 3:1 rule
Primary use: STEREO RECORDING OF ENSEMBLES AND ORCHESTRA'S
Stereo image: EXCELLENT
Center image: OKBest for: Working with the mid to far field
Advantage: Better stereo imaging
Notes:
The wide stereo employs a 3:1 rule whereby the distance between mics is 3 times greater than the distance of the source. For large orchestra, an additional center mic is often used. This provides better stereo imaging but does not make for good mono compatibility.Actually RESPECTFULLY, you have it backwards phase cancellation happens when two mics pick up the same source at the same exact time and amplitude and frequency. The polar patterns overlap making this happen. This normally happens at one frequency like for example if I had two Omni mics on a single singer and he or she was hot at 2.5k I would need to apply the three * to one ratio to avoid phase cancellation and the peek frequency or dominant frequency.
Your scenario of the rule needing to be applied with two different sources would be almost impossible to get any kind of phase problem. Hence the need to space mics with such open polar patterns (OMNI) in the first place. This is the reason why you never see a true stereo one point Omni mic; it would be a phase cancellation nightmare.Aaah, I see, the much misunderstood 3:1 rule.
And now, sorry for the emphasis.
The rule of thumb is ONLY of any use when you use two mics to record two DIFFERENT sound sources and want the two sources to be SEPARATED. So if you want one channel to have the lead singer and one to have the backup singer it is applicable. If then the singers are each one meter away from his/her mic, then the mics should be at least three meters from each other. Then each mic will basically only have one singer, allowing you to mix and match without much problem with phase issues and bleed between the mics. As with any rule of thumb it certainly does not work in every circumstance. It is a useful starting point for mulitmicing things in the studio or on the stage.
It has ABSOLUTET NO RELEVANCE for the distance between the two mics that make up a stereo pair. Here we want both mics to capture every source to some degree. The arrival time and volume differences are queues for our brain to recreate the stereophonic landscape. How to setup the mics is ruled by what stereo image you get, and then both mics need to get at least part of the picture, exactly as your ears.
Once more, sorry for shouting -- this seems to be a very common misconception.
Gunnar
Sorry Chris, but Gunnar is correct. The 3:1 rule is for multiple mics on separate sources. it is a multi-miking rule and does not apply to a single stereo pair. You are correct in noting that comb filtering is caused by the interference pattern of a single source, picked up by two mics and then summed again (either electronically or in air). The 3:1 rule works by getting each source/mic pair far enough away from the next that any inevital bleed is or or less inconsequential for phase issues. The rule has nothing to do with polar patterns other than more discriminating patterns can, by attenuation, help to reduce bleed and limit the comb filtering that the 3:1 rule aims to achive using distance. The different path lengths between the source and the 3:1 separated mics proivides both attenuation and phase differences between the signals of all the mics that are picking up that souce, both intentionally (mic on that source) and unintentionally (bleed from other mics).
It is physically impossible to apply the 3:1 rule to stereo micing, follow me here:
For stereo miking where some part of the source (say, the center of the stage) is equidistant from each mic, you cannot have more than a 2:1 ratio of source to mic vs. mic to mic distance. The only geometry that would acheive a 2:1 ratio would be to put the mics in a line with the source on the midpoint of that line, centered between the mics. As soon as you move the source away from the line the ratio drops. An equilateral triangle of source and mics would have a 1:1 ratio.
.. can't do it in this 3 dimentional space universe.
.. can't do it in this 3 dimentional space universe.
Now this is only true for this 3 dimensional EUCLIDEAN space universe, some of the newer halls with a non-Euclidean metric allow all sorts of innovative mic placement. However the mass or energy densities needed to sustain the local curvature of space in such halls can play havoc with unbalanced circuits, and you might as well kiss your time-code generator goodbye, unless you have something like the new Sound Devices Hyperspace 744 with a general relativistic invariant time-code function. This will be useful if you want to keep the music on your tape from ending before it actually begins.
Jeff
does cell phone interference exist there?
you guys simply lost me...
OK. no agreement if the 3:1 rule applies or not.
However, is it possible to say under which conditions a short spacing of 1 to 8 feet should be a good choice?
And of course I got very curious abt. the J Disc. The thread 'spaced Omnis vs. J/disc' has total 31 pages, so much info but I struggle to get the essence of it, I'd need a resumen stating all the important points. I'd be very happy to get clarified:
- Generally Omnis are used with J disc, but also subcard, even cards can be used. Should Omnis be the default choice, or when could cards be the better choice?
- Which would be the easiest to build but effective well working DIY J disc? Many build their own disc but modified it later. Why and how for which reason? Would a hard rubber disc make a good disc?
- Which would be your prefered Mic positioning using the J disc? Separation, pointing? Closer to the disc gives better separation, further away less separation and...? Would they usually be pointed streight forward?
- Is there any other important point?
Well, sure my questions are simplistic as the answers must depend on circumstances, but somethng like a dummy guide for J Disc would be just great.
I tried J-disc with C-483's for Taj Mahal at Red Rocks a while ago. It sounded OK, but I may try C-481's next, since I don't have the CK-62's yet. I have a pair of MSH-1A's on the way that I really want to try baffled too.
Easy now, didn't mean to raise anyone's ire. It's a simple fact of geometry that it is impossible to have two mics three times as far apart as they both are from the same source (as would be the case with a stereo pair recording a single source). Draw a diagram or get out the tape measure.. can't do it in this 3 dimentional space universe. I completely respect your experience and the reputation of GEFELL, but the information on their site is wrong, perhaps their english translation is to blame.
Now if the source is large like a chorus or orchestra, it is possible to have one part of the large source close enough to one of the mics to achieve a 3:1 ratio between that one part of the large source and the two mics. Other parts of the source will have lower ratios. That's not what we are really talking about, and confuses the issue by breaking up a single large source into multiple parts.
If you can show me a diagram or actual mesurements of a spaced pair setup you have used to record a single source with a spaced pair following the 3:1 rule you will convince me.. & we can dig up the bones of Pythagoras & Euclid and re-invent geometry.
No offense meant to you. The rule does of course exist, it just doesn't apply to a spaced stereo pair.. not because anyone says so, but because it cannot be done.You are 100% incorrect The 3:1 rule does exist argue your point with GEFELL one of the most respected names in audio.
I have been a sound engineer for 20 years I know my mic techniques and not because I read them from a book because I have used them. This rule can be applyed to close micing and to distant micing BUT it is only a guidline I was only trying to say that this rule dose exist and it is used sometimes. The fact that someone says this rule does not exist does not make it so. Furthermore this rule does not always have to be used it depends on your situation.
Chris Church
Here is the url for the info I have posted. http://www.gefell-mics.com/stereo_mic_techniques.htm
Wide stereo
Set-up: Two directional or omnidirectional spread using the 3:1 rule
Primary use: STEREO RECORDING OF ENSEMBLES AND ORCHESTRA'S
Stereo image: EXCELLENT
Center image: OKBest for: Working with the mid to far field
Advantage: Better stereo imaging
Notes:
The wide stereo employs a 3:1 rule whereby the distance between mics is 3 times greater than the distance of the source. For large orchestra, an additional center mic is often used. This provides better stereo imaging but does not make for good mono compatibility.Actually RESPECTFULLY, you have it backwards phase cancellation happens when two mics pick up the same source at the same exact time and amplitude and frequency. The polar patterns overlap making this happen. This normally happens at one frequency like for example if I had two Omni mics on a single singer and he or she was hot at 2.5k I would need to apply the three * to one ratio to avoid phase cancellation and the peek frequency or dominant frequency.
Your scenario of the rule needing to be applied with two different sources would be almost impossible to get any kind of phase problem. Hence the need to space mics with such open polar patterns (OMNI) in the first place. This is the reason why you never see a true stereo one point Omni mic; it would be a phase cancellation nightmare.Aaah, I see, the much misunderstood 3:1 rule.
And now, sorry for the emphasis.
The rule of thumb is ONLY of any use when you use two mics to record two DIFFERENT sound sources and want the two sources to be SEPARATED. So if you want one channel to have the lead singer and one to have the backup singer it is applicable. If then the singers are each one meter away from his/her mic, then the mics should be at least three meters from each other. Then each mic will basically only have one singer, allowing you to mix and match without much problem with phase issues and bleed between the mics. As with any rule of thumb it certainly does not work in every circumstance. It is a useful starting point for mulitmicing things in the studio or on the stage.
It has ABSOLUTET NO RELEVANCE for the distance between the two mics that make up a stereo pair. Here we want both mics to capture every source to some degree. The arrival time and volume differences are queues for our brain to recreate the stereophonic landscape. How to setup the mics is ruled by what stereo image you get, and then both mics need to get at least part of the picture, exactly as your ears.
Once more, sorry for shouting -- this seems to be a very common misconception.
Gunnar
Sorry Chris, but Gunnar is correct. The 3:1 rule is for multiple mics on separate sources. it is a multi-miking rule and does not apply to a single stereo pair. You are correct in noting that comb filtering is caused by the interference pattern of a single source, picked up by two mics and then summed again (either electronically or in air). The 3:1 rule works by getting each source/mic pair far enough away from the next that any inevital bleed is or or less inconsequential for phase issues. The rule has nothing to do with polar patterns other than more discriminating patterns can, by attenuation, help to reduce bleed and limit the comb filtering that the 3:1 rule aims to achive using distance. The different path lengths between the source and the 3:1 separated mics proivides both attenuation and phase differences between the signals of all the mics that are picking up that souce, both intentionally (mic on that source) and unintentionally (bleed from other mics).
It is physically impossible to apply the 3:1 rule to stereo micing, follow me here:
For stereo miking where some part of the source (say, the center of the stage) is equidistant from each mic, you cannot have more than a 2:1 ratio of source to mic vs. mic to mic distance. The only geometry that would acheive a 2:1 ratio would be to put the mics in a line with the source on the midpoint of that line, centered between the mics. As soon as you move the source away from the line the ratio drops. An equilateral triangle of source and mics would have a 1:1 ratio.
Ok... I'm not a very handy guy and doubt I could make my own but would love to try a JDisk with my 482s or the TLs I have on the way. Anyone out there that has made one that would like to make another that won't break the bank? PM Me....
Stay Kind,
Dana
Ok... I'm not a very handy guy and doubt I could make my own but would love to try a JDisk with my 482s or the TLs I have on the way. Anyone out there that has made one that would like to make another that won't break the bank? PM Me....
Stay Kind,
Dana
You just need some pockets on the corners and a set of miniature billiard balls
Yeah, my choice of that green was based on the mark-down bin in the fabric dept. at Walmart. I kind of like it that color. :)
I got 2 yards for under 2 dollars.
I agree with Chris. It applies to both situations.
Gunnar was right on the fact that it applies to seperate sources, but was wrong about it not applying to stereo micing.
You are 100% incorrect The 3:1 rule does exist argue your point with GEFELL one of the most respected names in audio.
I have been a sound engineer for 20 years I know my mic techniques and not because I read them from a book because I have used them. This rule can be applyed to close micing and to distant micing BUT it is only a guidline I was only trying to say that this rule dose exist and it is used sometimes. The fact that someone says this rule does not exist does not make it so. Furthermore this rule does not always have to be used it depends on your situation.
m the line the ratio drops. An equilateral triangle of source and mics would have a 1:1 ratio.
so many less rules to remember with baffled omnis!
They tend to regard "optimum distance" between two omni mics to be between 40 and 60 centimeters (a foot is about 30cm). I tend to end somewhere about there as well.
With regards
Gunnar
so many less rules to remember with baffled omnis!
:shrugs: ymmv
so many less rules to remember with baffled omnis!
:shrugs: ymmv
Amen! ;D I dont use rules or templates anymore, I find that I always have to vary the established configurations to get the sound that I am searching for. I never use DIN, DIN(a) or XY. I always use A-B, Blumlein, M-S, 3 omnis, or modified NOS( 110-120 degrees and 12-14inches capsule separation),OSS, and soon, Decca Tree. >:D
Gunnar, as you know, there are no surefire no or yes answers. There is no wrong.but, the rule exists, period. End of story. whether or not you find it pertinent is irrelevant.
No offense, but I think you may be better off not worrying about trying to change established rules that were written by our recording elders. Sure it was written before you could time align in DAWs and whatnot, but it DOESNT MATTER. The rule exists.
They tend to regard "optimum distance" between two omni mics to be between 40 and 60 centimeters (a foot is about 30cm). I tend to end somewhere about there as well.
With regards
Gunnar
They tend to regard "optimum distance" between two omni mics to be between 40 and 60 centimeters (a foot is about 30cm). I tend to end somewhere about there as well.
With regards
Gunnar
The weird thing is that nobody seems to make a bar this size. After reading a few weeks back in one of these threads about a great Handel tape made with omnis at 45 cm apart (Teddy's friend?), I tried to get a 45 cm bar, SabraSom makes 1 meter and 30 cm but nothing in between, every other manufacturer seemed to make shorter. Luckily Jerry Bruck at Posthorn Recordings thought he could use a 50 cm bar too, so he sawed a one meter SabraSom bar in half and now we both have 50 cm mounts. Will be trying it out in September.
Jeff
so many less rules to remember with baffled omnis!
:shrugs: ymmv
Amen! ;D I dont use rules or templates anymore, I find that I always have to vary the established configurations to get the sound that I am searching for. I never use DIN, DIN(a) or XY. I always use A-B, Blumlein, M-S, 3 omnis, or modified NOS( 110-120 degrees and 12-14inches capsule separation),OSS, and soon, Decca Tree. >:D
Funny thing is that I find my desire to be discreet, the bands config, and the venue's layout and attitude towards me drive my setup more than anything else, LOL! God forbid, I could actually setup the way I'd really want to. Heh...
I just found this. The stuff that relates to this thread is at the bottom... quite interesting...
http://www.regonaudio.com/MICROPHONE%20THEORY%20word.htm
so many less rules to remember with baffled omnis!
:shrugs: ymmv
Amen! ;D I dont use rules or templates anymore, I find that I always have to vary the established configurations to get the sound that I am searching for. I never use DIN, DIN(a) or XY. I always use A-B, Blumlein, M-S, 3 omnis, or modified NOS( 110-120 degrees and 12-14inches capsule separation),OSS, and soon, Decca Tree. >:D
Funny thing is that I find my desire to be discreet, the bands config, and the venue's layout and attitude towards me drive my setup more than anything else, LOL! God forbid, I could actually setup the way I'd really want to. Heh...
Truth to all that. Now we're in the real world again!
Honestly I was hesitant to even comment earlier in the thread, given my amateur status and with a web page of the inimitable MG stating otherwise. No doubt overly oppressive, control freak, freedom hating rule makers dreamed up the 3:1 rule eons ago. My personal take is that it applies to individual mics on separate sources and doesn't apply to stereo mic’ing. Another personal take is most of these rules are really just guidelines and suggestions and nothing beats experimenting and listening. I’ve learned more from moving mics around while monitoring through some phones with good isolation than from anything else, just from the immediate feedback I get. But, two things irked me on to post:
1. simple practical application - 3:1 works and works really well for individual mic’ing of separate sources on stage or any sources summed together in my limited experience. 3:1 doesn't work so hot for spaced omni stereo arrays in my slightly less, but still limited experience (ignoring geometry for now). In fact, off the cuff, I’d say reversing the ratio to 1:3 isn’t even enough most of the time and 10:1 is probably more like it, but I’d certainly never state that as a rule. If the rule states that a spaced pair of mic’s in a stereo pair should be 3 times farther apart than they are from the source, that rule just plain doesn’t work in my experience. Which makes me think it’s a mis-application of the original rule, after all aren’t these rules supposed to be good starting points at least? (especially since they’re only suggestions now that we’ve broken free from the domination of rule making oppressors)
2. some rules just can't be broken or agued away unless overwhelming evidence to the contrary is demonstrated – I’m talking about the laws of physics and mathematics. It remains a fact that two mics can't be 3 times as far away from each other as they are from the same point source, unless everyone in the venue uses their cell phones simultaneously to place calls to Steven Hawkings’ answering machine (which oddly enough sounds just like him). The rule just can’t apply since it is overruled by the pesky, domineering, micromanaging universe we live in.
The only time it could conceivably be applied to a stereo pair is when mic’ing a very large source (like a choir or orchestra that can be considered one source, guitarist stage left and keyboard guy stage right are two separate sources if your stereo mics are on stage) with the mics very far apart and very close in, at well a 3:1 ratio. Try it and see if it seems like a good rule. Seems to me there would be a rather distant and indistinct center image, but I’ll defer to those of you who get to do this sort of thing regularly.
Other arguments:
Arguing that it doesn’t even apply in the large source like a chorus case is a link to a Bruce Bartlett article on ProSoundWeb.com which states: “The 3:1 rule cannot be applied to miking a choir with a few mics. Why? Most of the singers are somewhere between the mics, and those singers will be picked up with some phase interference. However, since each singer is in a different position relative to the mics, each singer is heard with a different coloration. The effect averages out over all the singers and so is not very audible.”
I often see it stated that the rule applies to mics that will be summed to a single channel, ruling out stereo.
Isn’t the whole rational for the rule to reduce comb filtering issues? Usually I see the rational stated as something like: “This creates a level difference of at least 9 dB between microphones, which reduces the comb-filter peaks and dips to an inaudible 1 dB or less”. Spacing your AB pair that much will certainly do that, so much so that the phase information between the two will be nearly uncorrelated.
None of the first three pages of a Google search turned up links which apply it to stereo mic’ing.
Oh good, quitin' time. I’ll shut up now. Apologies for the overly long post.
I do not want to argue with you but, The 3:1 rule does exist. I am not saying I use it but it’s out there, for some applications it would work just fine. You can not quantify every single technique and say this will not work or this will work every single situation is different, and requires different techniques. No amount of book reading prepares you for the real world, sometimes out trusted techniques work sometimes they don’t. My whole point was that this technique in some situations is valid and not just with a single MONO source with stereo ones too.
I don’t think anyone here can say that this technique or that technique, work or do not work unless they are in the exact same room with the exact same source on the exact same day> so your argument is moot.
It’s great to say I like this technique or that, but in audio one must be careful of shooting down something because a book told you its wrong. I have seen the most stupid ass shit work in real life, things that don’t make any sense, but on that day with that band or source they did. We must remember never to close our eyes to that. There are many people out there recording, that have not got a clue, but they try things and they find there own way. I say what ever you have to do to get the sound you want, you do. No matter how stupid the 3:1 rule is, it’s just one more thing in the toolbox of audio tricks that we can all use. Why say it’s not a valid technique? Are you the Technique police? :P
I say what ever you have to do to get the sound you want, you do. No matter how stupid the 3:1 rule is, its just one more thing in the toolbox of audio tricks that we can all use...
I do not want to argue with you but, The 3:1 rule does exist. I am not saying I use it but it’s out there, for some applications it would work just fine. You can not quantify every single technique and say this will not work or this will work every single situation is different, and requires different techniques. No amount of book reading prepares you for the real world, sometimes out trusted techniques work sometimes they don’t. My whole point was that this technique in some situations is valid and not just with a single MONO source with stereo ones too.
I don’t think anyone here can say that this technique or that technique, work or do not work unless they are in the exact same room with the exact same source on the exact same day> so your argument is moot.
It’s great to say I like this technique or that, but in audio one must be careful of shooting down something because a book told you its wrong. I have seen the most stupid ass shit work in real life, things that don’t make any sense, but on that day with that band or source they did. We must remember never to close our eyes to that. There are many people out there recording, that have not got a clue, but they try things and they find there own way. I say what ever you have to do to get the sound you want, you do. No matter how stupid the 3:1 rule is, it’s just one more thing in the toolbox of audio tricks that we can all use. Why say it’s not a valid technique? Are you the Technique police? :P
Chris,
He is not deneying that the rule exists. His point is that it isn't physically possible to do with a single source and he is right. Say there is a guitar player you want to mic with stereo omni's from 10' back. Per the rule you would then be 30' apart on the omni's right? His point is that by spreading the microphones out 30', each mic is no longer 10' away from the source. If the rule stated that the center of the mic patern should be 10' from the source, or the mics should be 10' from the outside ends of the source (like a large orchestra) then the rule would be physically possible, but as it is stated in it's simple form it isn't possible to do. I think his interpratation of the rule as being applicable for micing seperate sources makes sence. After a certain distance you are not going to get bleed from other sources. If you are micing a guitar cabinet from 2" away and a bass cabinet from 2" away, you would need to make sure that the capsuls are atleast 6" away from the oposite source. My logic tells me he is right about this. This rule, without a few if's, and's, or but's is literally physically impossible to use when mic'ing a single source in stereo. Micing 2 seperate sources, in stereo, without bleed from one to the other, this rule makes a ton of sence. When micing a single source in stereo you WANT bleed from one to the other, without it is not a stereo recording. it is 2x mono! Hard panned omni's would just be stupid for an ambient stereo recording. The 3:1 rule should be called the "hole in the middle stereo mic technique". It is foolish to tell people that this is a propper way to run stereo spit omni's.
Matt
I do not want to argue with you but, The 3:1 rule does exist. I am not saying I use it but it’s out there, for some applications it would work just fine.
You are talking about one application of the rule lets say, I wanted to mic a symphony orchestra. I had a cardioid in the center and two omni mics with the 3:1 rule; this would be a real world application of this law. I think that the 3:1 rule is not for every situation just like XY.
But it can be used for some.
Chris Church
You are talking about one application of the rule lets say, I wanted to mic a symphony orchestra. I had a cardioid in the center and two omni mics with the 3:1 rule; this would be a real world application of this law. I think that the 3:1 rule is not for every situation just like XY.
But it can be used for some.
Chris Church
Hmm. Cannot follow you? What distances are you talking about. Please make a drawing and call of the distances.
Or, do you mean one orchestra and three mics? That is not the 3:1 rule.
I do a bit of symphony orchestra recordings as an amateur. There are many setups in common use. One used quite successfully for a long time by one of the classic houses was three omnis on a line straight in front of the orchestra. Another common setup is three omnis setup as above the orchestra in something called a Decca tree. I have never seen a single cardioid with two flanking omnis as a setup, never heard of it before. I would dare to say that it is not any standard technique.
A quite different thing is that today almost all symphony orchestra recordings use a lot of spot mics. A recording might have 50 mics and sometimes even more. Doing this right is something very different from setting up two mics to a stereo pair, so lets keep that out of the discussion.
Gunnar
I do not want to argue with you but, The 3:1 rule does exist. I am not saying I use it but it’s out there, for some applications it would work just fine.
We all agree there is a 3:1 rule-of-the-thumb rule. It exists. It is a usable starting point.
But what we are saying is that IT DOES NOT APPLY TO THE DISTANCE BETWEEN THE TWO MICS IN A STEREO PAIR .
Sorry for shouting. I will say it again, it describes something else than how to set up two mics as a stereo pair.
Again, when you setup tow mics as a stereo pair, do follow the guidelines of great people going ahead of us. None of them ever uses the 3:1 rule in this context.
I am sort of getting agitated here. Feel like I am talking to kids that does not want to listen. Or are you trying to make me angry? Guess what, I´m sort of getting there.
Talking about 3:1 and stereo pair in the same sentence is based on a total misunderstanding. Total, utterly off. Has nothing to do with each other.
If nothing else it is physically impossible! How could it then be the preferred setup? Guys, do make a drawing (paper and pen)!
Gunnar
I give up your right I am wrong ok how’s that end of argument I don’t want to argue about mic techniques I have been a sound engineer for 20 years. You guys continue the discussion with out me.
[/quote]You are talking about one application of the rule lets say, I wanted to mic a symphony orchestra. I had a cardioid in the center and two omni mics with the 3:1 rule; this would be a real world application of this law. I think that the 3:1 rule is not for every situation just like XY.
But it can be used for some.
Chris Church
Hmm. Cannot follow you? What distances are you talking about. Please make a drawing and call of the distances.
Or, do you mean one orchestra and three mics? That is not the 3:1 rule.
I do a bit of symphony orchestra recordings as an amateur. There are many setups in common use. One used quite successfully for a long time by one of the classic houses was three omnis on a line straight in front of the orchestra. Another common setup is three omnis setup as above the orchestra in something called a Decca tree. I have never seen a single cardioid with two flanking omnis as a setup, never heard of it before. I would dare to say that it is not any standard technique.
A quite different thing is that today almost all symphony orchestra recordings use a lot of spot mics. A recording might have 50 mics and sometimes even more. Doing this right is something very different from setting up two mics to a stereo pair, so lets keep that out of the discussion.
Gunnar
Ha! That painting is spot on, Teddy. Who's the artist?
Gunnar, how about you put away your internet dick and spend your time worrying about something else ::) Youve stated your point over and over and over and over......who cares but you?
I also suggest going easy on the insults. or things can, and will go downhill very quick here. Let it go and your life will be a lot easier.
and Im sorry, but the "talking to kids who dont want to listen" comment makes you sound like a real dick. One word for you, Gunnar--Humility
Gunnar, how about you put away your internet dick and spend your time worrying about something else ::) Youve stated your point over and over and over and over......who cares but you?
I also suggest going easy on the insults. or things can, and will go downhill very quick here. Let it go and your life will be a lot easier.
and Im sorry, but the "talking to kids who dont want to listen" comment makes you sound like a real dick. One word for you, Gunnar--Humility
If any of my writings were interpreted as insults I am very sorry about that, none of them was ever meant as that. I ask you to forgive me for that.
As for talking to kids I was trying to illustrate my feeling about the discussion was frustration, not in any way implying that I consider anyone to be a kid. Quite on the contrary I expect you to be people that are open to arguments and willing to either accept arguments or willing to give logical arguments allowing me to change views and learn in the process. If I say that the earth is flat and you say it is round, I expect you to give logical arguments allowing me to understand where and how I am wrong.
So I guess I will leave it at this:
- some believe the 3:1 rule applies
- I am probably an idiot but I cannot for the world understand how (as to me it is a logical and physical impossibility)
- I am not alone in not understanding it
What is sad is if this keeps people away from trying spaced omnis in recordings.
And once more, if anyone took offense from my writings, this was not in any way my intention. I ask you to forgive me if that was the error.
Gunnar
I give up your right I am wrong ok how’s that end of argument I don’t want to argue about mic techniques I have been a sound engineer for 20 years. You guys continue the discussion with out me.
^^^^^^^^^^^^^^^^^^^^^^^^^^(http://www.oddgames.com/daniel/graphics/angry_man_s.jpg)You are talking about one application of the rule lets say, I wanted to mic a symphony orchestra. I had a cardioid in the center and two omni mics with the 3:1 rule; this would be a real world application of this law. I think that the 3:1 rule is not for every situation just like XY.
But it can be used for some.
Chris Church
LMAO
Gunnar, noone is going to stop using any mic technique based on what theyve read on a message board. as for the insults thing, I know as well as anyone that it is easy to sound obnoxious. (ive been called out quite a few times myself).
As for the 3:1 argument, I say that you have presented your thoughts well, and you maybe should leave it at that. It doesnt matter if you convince people or not. All you can hope to do is present your side of it.
As for the insults thing, I was just warning you. Once people start here, things get ugly rather quick. Pile ons and blow ups are common place. ;) Plus, Chris Church has a storm cloud that follows him everywhere. I think he is the Antichrist. Choose your battles wisely. ;)Gunnar, how about you put away your internet dick and spend your time worrying about something else ::) Youve stated your point over and over and over and over......who cares but you?
I also suggest going easy on the insults. or things can, and will go downhill very quick here. Let it go and your life will be a lot easier.
and Im sorry, but the "talking to kids who dont want to listen" comment makes you sound like a real dick. One word for you, Gunnar--Humility
If any of my writings were interpreted as insults I am very sorry about that, none of them was ever meant as that. I ask you to forgive me for that.
As for talking to kids I was trying to illustrate my feeling about the discussion was frustration, not in any way implying that I consider anyone to be a kid. Quite on the contrary I expect you to be people that are open to arguments and willing to either accept arguments or willing to give logical arguments allowing me to change views and learn in the process. If I say that the earth is flat and you say it is round, I expect you to give logical arguments allowing me to understand where and how I am wrong.
So I guess I will leave it at this:
- some believe the 3:1 rule applies
- I am probably an idiot but I cannot for the world understand how (as to me it is a logical and physical impossibility)
- I am not alone in not understanding it
What is sad is if this keeps people away from trying spaced omnis in recordings.
And once more, if anyone took offense from my writings, this was not in any way my intention. I ask you to forgive me if that was the error.
Gunnar