[MrGreen]

This is an odd thread, and I'm not sure I'll get much in the way of help anywhere on the internet, since it is extremely niche.

I was wondering if anyone could help me out with the benefits of a Schneider disc over a Jecklin Disc. For those who are not aware, these are acoustic membranes placed between a stereo pair of omnidirectional mics, and the acoustic "shadow" produces the effect we hear in some binaural recordings.

I can tell you off the top of my head, that the dummy head produces the strongest effect, and is also significantly better at front and rear images than a Jecklin disc. 

But, does anyone know much about this? Or, are they able to recommend literature on the subject?

 

[LFF]

That's a tough choice and it really comes down to what they are made out of.
 
The jecklin disc is by far the more universal of the two. It's more compatible with speakers and headphones.
 
The schneider is a compromise between a holophonic microphone (aka a sphere microphone) and a jecklin disc. It provides very similar results to a jecklin disc but is slightly less compatible with speakers.
 
I made and had recordings using all the "binaural" set-ups including dummy head, holophonic, jecklin, schneider, blumlein difference technique and a few other tests. By far the most compatible with all systems was the holophonic microphone and that's the one I stuck with...that and my dummy head.
 
Feel free to ask any specific questions. You can also PM me.

 

[MrGreen]

Have you made your own Jecklin disc? Was there a guide you followed?

What are some examples of decent holophonic microphones? Does the schneider disc have superior front and rear imaging, like the dummy head?
 
Have you used stereo mics with a membrane built in between the two (so basically a miniature jecklin disc)?

Thanks!

 

[LFF]

 
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Have you made your own Jecklin disc?

 
Yes. I have made several.

 
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Was there a guide you followed?

No. It's not rocket science. A Jecklin disc is supposed to be a very simplified reproduction of the human head. The disc is usually 8 inches in diameter and covered in foam or carpet. The mic's are placed 4 inches away from the center of the disc. However, I found that making the disc 12-14 inches in diameter and setting the mics 8 inches from the disc worked best (double Jecklin's original distance).

 
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Originally Posted by MrGreen /img/forum/go_quote.gif
 
What are some examples of decent holophonic microphones?

Tough question because I don't think there are any. The best holophonic microphone you can get is the Schoeps Stereo Sphere Microphone Model KFM-6. However, just the basic microphone will run you at least $6,000.00 USD. A company named "THE" also makes a sphere microphone except that it is made out of wood. The quality is great as well but also runs into the multi-thousand dollar range...if you can find one.
 
If you go to my blog and listen to one of my Adventures In Binaural Recording, what you hear is a slightly modified DIY holophonic microphone that I built that cost me under $500.00! It's recording quality is similar to much more expensive microphones and it's size is very portable.
 

 
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Originally Posted by MrGreen /img/forum/go_quote.gif
 
Does the schneider disc have superior front and rear imaging, like the dummy head?

 
No. Nothing really compares to a properly designed, properly built and properly post-processed dummy head recordings. The Schneider is only slightly better than a Jecklin and even then it depends what you are recording. IMHO, it's only slightly better with regards to side positioning but about the same with regards to front and back localization. In other words, the main difference between the two is in soundstage. I would personally use a Schneider Disc for small ensembles and a Jecklin Disc for large ensembles like a symphony orchestra. If you want accurate frontal and rear localization, it's best to go with a slightly modified holophonic microphone or a dummy head.

 
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Have you used stereo mics with a membrane built in between the two (so basically a miniature jecklin disc)?

 
Yes. I have experimented with various stereo minimalist mic'ing techniques. A mini-Jecklin or mini-Schneider will not provide the soundstage nor the localization you are looking for. I have found that with both designs, bigger is usually better. However, if it is too big, you will have to adjust your sound during post processing to compensate for certain problems. However, once that compensation is done, it will sound phenomenal. My recommendation would be to stick to a disc that is around 12 - 14 inches in diameter and the microphones spaced 8 inches from the center of the disc. With that configuration, you will not really need much post-processing.
 
Critical to all these techniques is PLACEMENT! All of these techniques require very careful placement of the microphones as they will pick up everything...every little nuance, cough, movement, reflection, etc. You need a good room, good musicians and good placement and very accurate monitoring for these techniques to sound best.
 
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Thanks!
 

You're welcome.

 

[MrGreen]

Hi;

For an orchestra, would you place the disc out the front of the orchestra, or in the middle of it?

How well will the disc pick up a sound rotating "around" the disc, if at all?

Can I have a look at one of your discs? 

Do you have any omni recommendations? I was thinking getting some measurement condensers with a fairly flat response. But I'm not sure if this would require me to EQ treble down, with a disc? I assume with a dummy head, I'd have to remove the diffuse field/freefield response (depending on the recording conditions) to make it ideal with most headphones.
 
Do you have any experience with the binaural cardiods you can buy that are basically IEMs that function in reverse?
 
There's a AKG D99C on ebay at the moment that I might consider, though the wood leaves concern for importing. But maybe I'll just try save money and build my own instead.

Thanks!
 

 

[LFF]

 
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Originally Posted by MrGreen /img/forum/go_quote.gif
 
For an orchestra, would you place the disc out the front of the orchestra, or in the middle of it?
 

That really depends on the conductor. Some conductors can be noisy, and if you place it near him/her then the microphone set up will pick up any grunts, comments etc from the conductor. If he/she is fairly silent, then I like to place it somewhere behind, on top of or in front of the conductor.

 
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Originally Posted by MrGreen /img/forum/go_quote.gif
 
How well will the disc pick up a sound rotating "around" the disc, if at all?
 

If you record any rotating sound, it will record it just fine...enough to tell on headphones that something is going around the microphones.

 
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Originally Posted by MrGreen /img/forum/go_quote.gif

Can I have a look at one of your discs?
 

I don't have any pictures at the moment. I'll post some once I get home.

 
Quote:

Originally Posted by MrGreen /img/forum/go_quote.gif
 
Do you have any omni recommendations? I was thinking getting some measurement condensers with a fairly flat response. But I'm not sure if this would require me to EQ treble down, with a disc?
 

It depends how serious you are about this and what results you want to obtain and what method you will be using in the end. My favorite omni mics are the ones made by Earthworks but they are expensive. If money isn't that much of a concern, buy a matched pair of omni mics from earthworks. If money is a concern and you don't want to build your own microphones, then I would simply use two Behringer ECM8000 microphones. Both of these recommendations require phantom power so you will need a recorder that can provide phantom power like the Zoom H4n. The EQ is totally up to you. Personally I find that the recording will need more than just a treble adjustment to sound its best. PM me if you want me to master it for you.

 
Quote:

Originally Posted by MrGreen /img/forum/go_quote.gif
 
I assume with a dummy head, I'd have to remove the diffuse field/freefield response (depending on the recording conditions) to make it ideal with most headphones.

That depends on the results. The different fields are just a fancy way of saying post-process EQ. Again, I find that most recordings need some sort of EQ to sound their best.

 
Quote:

Do you have any experience with the binaural cardiods you can buy that are basically IEMs that function in reverse?
 
 

Yes. They are fun but I wouldn't use them for anything serious as they tend to pic up on your body movements. I would stick to omni microphones for 98% of minimalist stereo set-ups.

 
Quote:

Hi;
 
There's a AKG D99C on ebay at the moment that I might consider, though the wood leaves concern for importing.
 

I like HARRY but I would recommend you avoid him as it is a dated design and it sounds rather bad. The microphones inside HARRY are dynamic microphones and are very, very lo-fi. However, he does look cool and is always a great conversation piece. For high end recording purposes, those cheap Behringer microphones will provide much better sound than HARRY. If you want a better dummy head, consider a vintage Neumann K81 or building your own.

 
Quote:

Hi;

But maybe I'll just try save money and build my own instead.

 

That's what I eventually did and learned a great deal in the process. What works...what doesn't...how  to modify certain designs to maximize localization, what sizes work, what materials work best, etc. I even went as far as actually witnessing a human cadaver dissection of the skull, ear and inner ear.

 
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Thanks!
 

You're welcome! Happy to help and talk about this stuff as it's a huge hobby of mine.
 

 

[MrGreen]

I was thinking about either a pair of these (U-O for lower self noise) http://www.naiant.com/ucapsulespecification.html + a converter for PiP to Phantom power.

Or an electret like the Avenson STO-2

I've seen the ECM8000 before, and my main concern was that it has a low max SPL.

 

[LFF]

Quote:

I was thinking about either a pair of these (U-O for lower self noise) http://www.naiant.com/ucapsulespecification.html + a converter for PiP to Phantom power.

Or an electret like the Avenson STO-2

I've seen the ECM8000 before, and my main concern was that it has a low max SPL.

 
I have heard good things about the Avenson mics.
 
Consider that an spl of 120 is already at a level of discomfort and that 130 is the pain threshold. Mics with extremely high max spl are usually used for loud rock concerts or for mic'ing drums but I totally understand wanting a higher max spl rating. Better safe than sorry.
 
I'll post my pictures soon.
 

 

[MrGreen]

I remember reading somewhere that the Behringer's max SPL was 70 or 80 or so, before distortion goes way up. I was also looking for an option where I can get a good self-noise in case I decide to try out some field recording. Obviously the avenson, being a small condenser won't do that much better than the Behringer (and also other small options like earthworks, DPA etc), which is why I was thinking of the naiant option. The price would also allow me to experiment with 5.1 recording

 

[LFF]

Here is my jecklin disc. Keep in mind that I haven't used it in a long time.
 
It consists of a 12 inch circle with absorbing acoustic foam on either side all covered by black speaker cloth grill. Total cost to build was about $30.00!
 

 
Here is my custom designed holophonic microphone. It is basically a miniaturized and simplified human head. It has been filled with foam and the microphones are placed within the body. The dark pads are fabric that help reduce reflections near the microphones. Here it is mounted on a camera tripod.
 

 

 

[LFF]

Quote:

I remember reading somewhere that the Behringer's max SPL was 70 or 80 or so, before distortion goes way up. I was also looking for an option where I can get a good self-noise in case I decide to try out some field recording. Obviously the avenson, being a small condenser won't do that much better than the Behringer (and also other small options like earthworks, DPA etc), which is why I was thinking of the naiant option. The price would also allow me to experiment with 5.1 recording

No. The max spl is about 125 IIRC. The Dayton Audio EMM-6 (which is also great btw) has a max spl of 127 which is plenty good for almost everything.
 
Now...if you want to get into 5.1 recording...that's a whole 'nother world onto itself and one I have little experience in.

 

[MrGreen]

So the jecklin disc is a solid disc, rather than one of just foam, or tights (or thin fabric) suspended across a ring? That's interesting, and different to what I thought it'd be: I would have thought the lower frequencies would have gone "through" the disc, rather than "around"

What stands do you use to mount your microphones for jecklin recording? Do you suspend them from the disc with mounts, or next to it with regular stands?

Are the holes in the side of that head custom made, or did the mannequin head come like that?

 While I'm here, do you have any experience with room treating? Do you have any particular advice? I was thinking of making a vocal booth/anechoic chamber from some foam and fibreglass/fibreboard, but I'm not sure if the lack of reflections would result in the effect not working as well, or even indeed if "less is more" in terms of room treating


Do you have any recommendations for the IEM variety as well? I like the idea of picking up body movements, and it might be interesting to do something with that. Have you tried using them as canalphones? It is, afterall, my understanding that headphones and microphones are the same system running in reverse?

Cheers

 

[LFF]

 
Quote:

So the jecklin disc is a solid disc, rather than one of just foam, or tights (or thin fabric) suspended across a ring?

I have made both actually. A solid disc and a solid ring. I preferred the results of the solid disc. Part of the localization properties of this techniques comes from the "acoustic shadow" of the disc.

 
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What stands do you use to mount your microphones for jecklin recording?

 
I have two options with mine. I can hang it from a string or I can mount it on a regular microphone stand.
 
Quote:

Do you suspend them from the disc with mounts, or next to it with regular stands?
 

 
I can do both but for ease of use, I prefer to use regular stands.
 
Quote:

Are the holes in the side of that head custom made, or did the mannequin head come like that?
 

 
The entire thing is custom made.
 
I do have some experience with room treatments. What exactly are you doing? I thought you were just going to be recording a performance. Why do you need a vocal booth? Are you building a recording studio? What music do you want to record?
 
As for IEM's and headphones for microphones...not exactly the same. If you have attempted to record something with headphones, then you know they don't sound good as microphones. Ribbon microphones can act as mini speakers but they need to very close to your ear to sound ok. My advice is to keep the listening instruments for listening and vice versa.

 

[MrGreen]

Quote:

 
I thought you were just going to be recording a performance. Why do you need a vocal booth? Are you building a recording studio? 
 
 

 
I'm making a home studio, rather than recording performances. Once it's set up, I might look at recording live albums for my friends down at the jazz club.

I figured a vocal booth would be the easiest way to get a cleaner sound, though I wasn't sure if it would be problematic for a binaural recording. 
 
 
 
Quote:

What music do you want to record?

At the moment, an experimental ambient album, with lots of other genres thrown in. The main reason I want to go binaural (for the parts where it is possible) is to play with the idea of space. Same reason why I wanted to give 5.1 a go.
 
 

As for IEM's and headphones for microphones...not exactly the same. If you have attempted to record something with headphones, then you know they don't sound good as microphones. Ribbon microphones can act as mini speakers but they need to very close to your ear to sound ok. My advice is to keep the listening instruments for listening and vice versa.

That sucks, I would have liked an electrostat IEM that was a bit better than the baby stax.

 

[MrGreen]

Hi LFF,

I forgot to ask, how thick is your favourite disc? Do you find thinner discs are less effective?

I'm trying to experiment with ideas for cheap reflection killers, and was wondering much space the disc would need to take
 

Cheers.