"Real" sound pressure microphone

[NathanShirley]

I'm interested in knowing what exactly makes an omni microphone a "real" sound pressure microphone.

I was reading this description of the Jecklin Disk, and how they work (on the Josephson website), and it mentions only "real" sound pressure microphones will work with a Jecklin Disk. It also states that microphones with variable patterns are not "real" sound pressure microphones.

Basically I'm trying to determine if the AT4022 mics will be good candidates for a Jecklin Disk, they are omni, with no variable pattern, so I'm assuming they will work but wanted to make sure (they are directional to some degree at HF).

Many thanks!

[MichaelPatrick]

From the AT description AT4022 looks to me like a pressure mic.

Some background on pressure and pressure gradient transducers:

Pressure Transducers
Pressure Gradient Transducers

[NathanShirley]

Thanks, I'll take a look at these links, much appreciated!

[John Willett]

A switchable-pattern mic. is made from back-to-back cardioid capsules - adding the two together makes an omni (reverse the rear and it becomes a fig.8).

A "real" pressure omni is a single diaphragm sealed at the rear.

So, yes, the AT4022 looks like a real omni to me.

From what I remember, though, a Jecklin (or Schneider) disk works best with diffuse-field omnis (ie: ones with a treble lift rather than a flat frequency response) and I don't see the diagrams on the AT website to see what it is.

I have both a Jecklin and a Schneider disk, but tend to prefer the Schneider nowadays.

[MichaelPatrick]

Originally Posted by John Willett

I have both a Jecklin and a Schneider disk, but tend to prefer the Schneider nowadays.

John, as a brief aside, how far apart do you place the mic capsules on your Schneider disc? I've been using a 40cm to 46cm spacing with good results, and I rarely put them in the center of the disc. Usually the capsules are a little above and behind the center. I do this to get more L/R acoustic shadowing from the disc structure.

[NathanShirley]

Originally Posted by John Willett

From what I remember, though, a Jecklin (or Schneider) disk works best with diffuse-field omnis (ie: ones with a treble lift rather than a flat frequency response) and I don't see the diagrams on the AT website to see what it is.

I have both a Jecklin and a Schneider disk, but tend to prefer the Schneider nowadays.

Thanks John. This link should show the frequency response for the AT4022 (if you zoom in).

Now that you mention it, I do recall reading that these disks cut a bit of the HF. The AT4022 does seem to have a bit of HF lift, though it is a little bumpy, and I wonder what the optimal lift range would be.

And yes, I'm certainly starting to lean towards a Schneider disk myself.

[John Willett]

Originally Posted by MichaelPatrick

John, as a brief aside, how far apart do you place the mic capsules on your Schneider disc? I've been using a 40cm to 46cm spacing with good results, and I rarely put them in the center of the disc. Usually the capsules are a little above and behind the center. I do this to get more L/R acoustic shadowing from the disc structure.

I use the MB Schneider disc and the mics touch the ball at the centre. I have never actually measured the distance.


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[John Willett]

Originally Posted by NathanShirley

Thanks John. This link should show the frequency response for the AT4022 (if you zoom in).

Now that you mention it, I do recall reading that these disks cut a bit of the HF. The AT4022 does seem to have a bit of HF lift, though it is a little bumpy, and I wonder what the optimal lift range would be.

And yes, I'm certainly starting to lean towards a Schneider disk myself.

It looks more like a flat response with a wobbly top, rather than a proper diffuse-field omni.

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[rumleymusic]

I have both a Jecklin and a Schneider disk, but tend to prefer the Schneider nowadays.

I have actually never used either, how would you describe the differences between the two in a recording?

[aracu]

Another way of thinking about what makes an omni more of a "real" one is to take into consideration how large the body of the mic is and how it is designed and positioned to block off the least amount of sound from arriving, and to look at the response diagram to see how close the mic comes to having a even omni response from all sides of the mic.

[NathanShirley]

Originally Posted by aracu

Another way of thinking about what makes an omni more of a "real" one is to take into consideration how large the body of the mic is and how it is designed and positioned to block off the least amount of sound from arriving, and to look at the response diagram to see how close the mic comes to having a even omni response from all sides of the mic.

Originally Posted by john

It looks more like a flat response with a wobbly top, rather than a proper diffuse-field omni.

Interesting... you guys are making me wonder if I shouldn't consider a different pair of mics. The $500 price for a pair of AT4022 is a bit rough for me as it is, so I'll have to see. Any recommendations of something in that range that might prove better for Schneider disk use?

Thanks again for all the info.

[Teddy Ray]

OP

do yourself a favor and get this book

Amazon.com: The Microphone Book, Second Edition: From mono to stereo to surround - a guide to microphone design and application (9780240519616): John Eargle: Books

[Teddy Ray]

Originally Posted by rumleymusic

I have actually never used either, how would you describe the differences between the two in a recording?

I have both. The Schneider is more suitable for situations in which one will be listening to the recorded result on headphones... I haven't found the Schneider to have any other advantage over the OSS/Jecklin..

[MichaelPatrick]

Originally Posted by Teddy Ray

I have both. The Schneider is more suitable for situations in which one will be listening to the recorded result on headphones... I haven't found the Schneider to have any other advantage over the OSS/Jecklin..

I use a Schneider disc as a baffle between AB omnis spaced between 40 and 50 cm because it improves imaging.

I've looked for Schneider disc usage instructions and found it not well documented like the Jecklin disc. In fact, it seems to be a novelty without any theoretical or descriptive support such as Josephson's OSS (Jecklin disc) paper and published studies on binaural HRTF methods.

[mathieujm]

Originally Posted by NathanShirley

Interesting... you guys are making me wonder if I shouldn't consider a different pair of mics. The $500 price for a pair of AT4022 is a bit rough for me as it is, so I'll have to see. Any recommendations of something in that range that might prove better for Schneider disk use?

Thanks again for all the info.

The Beyer MC910 is advertised to be used in the distant field and its response curve correspond to what is advocated for the Jecklin/Schneider disk. But I don't have direct experience with them.

JMM

[NathanShirley]

Originally Posted by Teddy Ray

OP

do yourself a favor and get this book

Amazon.com: The Microphone Book, Second Edition: From mono to stereo to surround - a guide to microphone design and application (9780240519616): John Eargle: Books

I've just ordered it, saw you recommend this in another thread. Thanks!

[NathanShirley]

Originally Posted by mathieujm

The Beyer MC910 is advertised to be used in the distant field and its response curve correspond to what is advocated for the Jecklin/Schneider disk. But I don't have direct experience with them.

JMM

Yes, I've read many good things about these, of course for about $1200 a pair, I don't think I'll be able to swing them (and self noise seems a little high).

[Teddy Ray]

This Gentleman uses the Rode NT-5 (omni caps only) with the J-Disc.
Wayne Coniglio Productions - Live and Location*Audio Recording

(samples there)
Mr. Tony Faulkner has said great things about The Rode Mics..

and in case you aren't familar with Mr. Faulkner..look into his History/Recordings.

He is **the man**

Schoeps MK4, how much better than Rode NT5?

[John Willett]

Originally Posted by Teddy Ray

Mr. Tony Faulkner has said great things about The Rode Mics..

and in case you aren't familar with Mr. Faulkner..look into his History/Recordings.

He is **the man**

Schoeps MK4, how much better than Rode NT5?

Tony Faulkner has said great things about the Rode OMNI heads for the NT5 and 55, not Rode in general.


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[rumleymusic]

of course for about $1200 a pair, I don't think I'll be able to swing them

They run about $1000 in the US and $800 in Germany if you order online. Try www.Musik-service.de they have free shipping to the US and the page has english text options for easy navigating.

I've looked for Schneider disc usage instructions and found it not well documented like the Jecklin disc. In fact, it seems to be a novelty without any theoretical or descriptive support such as Josephson's OSS (Jecklin disc) paper and published studies on binaural HRTF methods.

I have read quite a bit of documentation on the Jecklin disk, but you are right , Schneider disk documentation is rather hard to find, other than fague discriptions on how it is a binaural "dummy head" approximation. Am I correct in assuming MBHO is the company one who makes these?

[MichaelPatrick]

Originally Posted by rumleymusic

I have read quite a bit of documentation on the Jecklin disk, but you are right , Schneider disk documentation is rather hard to find, other than fague discriptions on how it is a binaural "dummy head" approximation. Am I correct in assuming MBHO is the company one who makes these?

I believe you're right about MBHO, and a company called CoreSound also sells them, but I don't know if they manufacture or an OEM supplies them. I got mine from CoreSound.

[John Willett]

Originally Posted by rumleymusic

Am I correct in assuming MBHO is the company one who makes these?

My Schneider disk is the MB one.

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[panatrope]

Originally Posted by Teddy Ray

This Gentleman uses the Rode NT-5 (omni caps only) with the J-Disc.

I can just imagine the designer of the NT-45 capsule being given by Peter Freedman a copy of the KM183 response chart and suggesting "Make it like this!". If KM183s work in this app, then so will the NT-45 omnis. It seems like the sort of response a J-Disc would need.

They have been my main mics for distant outriggers and hall ambience mics giving good results (until I got a pair of Schoeps MK2S). The cardioid capsules never had any serious use. But overall, well made (in Oz!!).

[Teddy Ray]

Originally Posted by John Willett

Tony Faulkner has said great things about the Rode OMNI heads for the NT5 and 55, not Rode in general.


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I know what he said, as I was the original guy that asked him about them. (you couldn't believe he said such a thing and tried to correct me on it, remember? (just joshing with you)

If you notice the sentence above that, you can see that I mentioned those mics(NT-5) specifically....and I also linked to the thread in Which Mr. Faulkner talked about them... and..we are talking about Omnis in this thread...

so... I am quite certain the message was clear, John. but...I shall attach that caveat in all further references to make sure there is no confusion.

[NathanShirley]

Thanks for the thread link, I went ahead and read nearly the whole thing as it was quite entertaining! I suppose that is a great example of how subjective sound quality can be. Obviously (some) very experienced people on both sides of that particular microphone debate.

It did make me think the NT5 omni would be fine for my purpose. However some comments on its slow transient response worried me as I would need this for marimba and piano ensemble from time to time (amongst many other combinations).

And more than anything this thread seemed to emphasize how experienced engineers select from a large variety of mics depending on the situation at hand. Whereas I am forced to compromise with a single pair for budget reasons (and because I lack knowledge of what best to use when/how... which is one reason I have this strong interest in the disk separation methods).

Or perhaps I could settle for the AT4022 and just EQ it a bit in the HF, as it has such low self noise and from what I've read they are very robust?? At this point I find myself swimming in circles...

[MichaelPatrick]

A switchable pattern small capsule mic that's a real pressure omni is the Shure KSM141. You may want to consider those if for both flexibility and good sound. Here's a pair for sale at about half the new price: http://www.gearslutz.com/board/gears...-cardioid.html

[Teddy Ray]

Originally Posted by NathanShirley

Thanks for the thread link, I went ahead and read nearly the whole thing as it was quite entertaining!
It did make me think the NT5 omni would be fine for my purpose.

I have used the Rodes quite a bit(my pairs were lost forever,along with about 80 percent of my equipment) in my move from Germany to NC{long and painful story}

and I never noticed any issue with transient response, consider that at the time, I had Schoeps, DPA 4006, Gefell mk221, all the "top" microphone choices. anyway, I am just a hack, only been recording for 6 years or so, but I dare say that the words from Mr. Faulkner dispatch handily the words/misfires/generalizations of any naysayers. He is one of the greats, and was making records before I was a glimmer in my mothers eye. . I look up to him a great deal. His post 11 on the thread I referenced is particularly enlightening(and funny)

Tony Faulkner Discography at Discogs

[mathieujm]

Originally Posted by NathanShirley

Yes, I've read many good things about these, of course for about $1200 a pair, I don't think I'll be able to swing them (and self noise seems a little high).

Didn't know where you are !
Here in Europe the AT4022 and the Beyer MC910 are the same price (340 €)
JMM

[NathanShirley]

Originally Posted by MichaelPatrick

A switchable pattern small capsule mic that's a real pressure omni is the Shure KSM141. You may want to consider those if for both flexibility and good sound.

That is really good to know, I had just assumed the KSM141 was not a real pressure omni because of the switchable pattern. Well, even though they are more expensive they are certainly back in the running. Thanks for that bit of info! And thanks for the links explaining the pressure vs. pressure gradient cap's, very enlightening and well written.

[NathanShirley]

Originally Posted by Teddy Ray

I have used the Rodes quite a bit(my pairs were lost forever,along with about 80 percent of my equipment) in my move from Germany to NC{long and painful story}

and I never noticed any issue with transient response, consider that at the time, I had Schoeps, DPA 4006, Gefell mk221, all the "top" microphone choices. anyway, I am just a hack, only been recording for 6 years or so, but I dare say that the words from Mr. Faulkner dispatch handily the words/misfires/generalizations of any naysayers. He is one of the greats, and was making records before I was a glimmer in my mothers eye. . I look up to him a great deal. His post 11 on the thread I referenced is particularly enlightening(and funny)

Tony Faulkner Discography at Discogs

Germany to NC, sounds painful enough without losing all the equipment.

Thanks again for that link, I'm definitely strongly considering the NT5, along with the KSM141 (which I see Plush thinks highly of) now. And I'm going to look into the Beyer a bit further as well. I suppose at this stage I just need to seek out more audio samples and have another round of serious listening.

So you guys think I might as well cut the AT4022 out of the running for use with a disk? I do like the idea of having cardioid caps in case I need to use ORTF.