Actually, reading the article, seems more like a synth using optical cues for reconstructing notes.
In the absence of audible results, we're left in conjecture.

L

On Jun 27, 2022, at 11:40 AM, Terry Setter via groups.io <powerofthemuse@...> wrote:

?

Certainly it holds great promise for bird enthusiasts (and spies and perverts)!? Wouldn't it be something if these mics end up with an extraordinary musicality.? I know, I know, chances are slim, but at least it is a new avenue for development and that means new potential as well.

Actually, reading the article, seems more like a synth using optical cues for reconstructing notes.
In the absence of audible results, we're left in conjecture.

Le 27/06/2022 à 15:06, Jules Ryckebusch a écrit?:

Thet, you just hit the nail on the head. Worlds best contact microphone.?

Best Regards,?

Jules?

On Jun 27, 2022, at 08:26, thet <parenthetical@...> wrote:

?

Maybe I'm missing something because I didn't look at every detail of the explanation, but, seems to me that is equivalent to having a contact mic on each guitar.

If there is one laser beam on each guitar, as implied, then laser is only looking at one spot on the top of the guitar then the system is not picking up the whole sound of the guitar, but just one spot on the top which won't give a balanced sound.

We can already achieve good isolation between instruments if we attach a contact mic to each instrument.

The complete sound of an instrument is not adequately defined by the vibration of one point on its top.

So it's a fascinating optical technique, but not any sort of musical breakthrough.

On 27/06/2022 12:02, Wim wrote:

This came up on my readinglist today:

“?Researchers at Carnegie Mellon University have presented some remarkable audio from a new optical microphone system that uses cameras to see and reconstruct sonic vibrations. Remarkably, it can cleanly separate a single instrument playing in a group.”

This kind of sonic isolation is extremely difficult even for high-end audio microphones, so to be able to achieve it using nothing but two cameras and a laser? It feels a bit like black magic. But the results, which you can see in the video embedded at the end of this piece, are stunning.

Op zo 26 jun. 2022 om 13:36 schreef Jules Ryckebusch <ryckebusch@...>

I agree with Jerry and Tom. They are really comparing it to a laser microphone which is a single use case. This paper reads like a "Well we got it to work and there is slight numerical improvement in one aspect" As a tech thing it is great. As a Schoeps, Neumman, AKG, and Rode lose sleep at night thing? Not so much.

Jules

On Sun, Jun 26, 2022 at 6:16 AM Jerry Lee Marcel <jerryleemarcel@...> wrote:

Knowing that most of the noise is due to acoustic impedance, the diaphragm is still the most significant part of the equation.

We know that extremely low noise can be achieved by using undamped diaphragms, which in turn needs electronic frequency response compensation. The absence of data in this respect leaves me quite dubious.

An aggravating factor is that only a small part of the diaphragm is taken into account; since the S/N ratio decreases by 3dB every time the surface is halved. I'm not familiar enough with optical microphones, but a I doubt a laser ray has the capability to sample the whole diaphragm area. Conventional condenser mics do that natively.

Lack of comparative data leaves me only speculating.

--

Best Regards,

Jules Ryckebusch

214 399 0931

Thet, you just hit the nail on the head. Worlds best contact microphone.?

Best Regards,?

Jules?

On Jun 27, 2022, at 08:26, thet <parenthetical@...> wrote:

?

Maybe I'm missing something because I didn't look at every detail of the explanation, but, seems to me that is equivalent to having a contact mic on each guitar.

If there is one laser beam on each guitar, as implied, then laser is only looking at one spot on the top of the guitar then the system is not picking up the whole sound of the guitar, but just one spot on the top which won't give a balanced sound.

We can already achieve good isolation between instruments if we attach a contact mic to each instrument.

The complete sound of an instrument is not adequately defined by the vibration of one point on its top.

So it's a fascinating optical technique, but not any sort of musical breakthrough.

On 27/06/2022 12:02, Wim wrote:

This came up on my readinglist today:

“?Researchers at Carnegie Mellon University have presented some remarkable audio from a new optical microphone system that uses cameras to see and reconstruct sonic vibrations. Remarkably, it can cleanly separate a single instrument playing in a group.”

This kind of sonic isolation is extremely difficult even for high-end audio microphones, so to be able to achieve it using nothing but two cameras and a laser? It feels a bit like black magic. But the results, which you can see in the video embedded at the end of this piece, are stunning.

Op zo 26 jun. 2022 om 13:36 schreef Jules Ryckebusch <ryckebusch@...>

I agree with Jerry and Tom. They are really comparing it to a laser microphone which is a single use case. This paper reads like a "Well we got it to work and there is slight numerical improvement in one aspect" As a tech thing it is great. As a Schoeps, Neumman, AKG, and Rode lose sleep at night thing? Not so much.

Jules

On Sun, Jun 26, 2022 at 6:16 AM Jerry Lee Marcel <jerryleemarcel@...> wrote:

Knowing that most of the noise is due to acoustic impedance, the diaphragm is still the most significant part of the equation.

We know that extremely low noise can be achieved by using undamped diaphragms, which in turn needs electronic frequency response compensation. The absence of data in this respect leaves me quite dubious.

An aggravating factor is that only a small part of the diaphragm is taken into account; since the S/N ratio decreases by 3dB every time the surface is halved. I'm not familiar enough with optical microphones, but a I doubt a laser ray has the capability to sample the whole diaphragm area. Conventional condenser mics do that natively.

Lack of comparative data leaves me only speculating.

--

Best Regards,

Jules Ryckebusch

214 399 0931

On Jun 27, 2022, at 08:26, thet <parenthetical@...> wrote:

?

Maybe I'm missing something because I didn't look at every detail of the explanation, but, seems to me that is equivalent to having a contact mic on each guitar.

If there is one laser beam on each guitar, as implied, then laser is only looking at one spot on the top of the guitar then the system is not picking up the whole sound of the guitar, but just one spot on the top which won't give a balanced sound.

We can already achieve good isolation between instruments if we attach a contact mic to each instrument.

The complete sound of an instrument is not adequately defined by the vibration of one point on its top.

So it's a fascinating optical technique, but not any sort of musical breakthrough.

On 27/06/2022 12:02, Wim wrote:

This came up on my readinglist today:

“?Researchers at Carnegie Mellon University have presented some remarkable audio from a new optical microphone system that uses cameras to see and reconstruct sonic vibrations. Remarkably, it can cleanly separate a single instrument playing in a group.”

This kind of sonic isolation is extremely difficult even for high-end audio microphones, so to be able to achieve it using nothing but two cameras and a laser? It feels a bit like black magic. But the results, which you can see in the video embedded at the end of this piece, are stunning.

Op zo 26 jun. 2022 om 13:36 schreef Jules Ryckebusch <ryckebusch@...>

I agree with Jerry and Tom. They are really comparing it to a laser microphone which is a single use case. This paper reads like a "Well we got it to work and there is slight numerical improvement in one aspect" As a tech thing it is great. As a Schoeps, Neumman, AKG, and Rode lose sleep at night thing? Not so much.

Jules

On Sun, Jun 26, 2022 at 6:16 AM Jerry Lee Marcel <jerryleemarcel@...> wrote:

Knowing that most of the noise is due to acoustic impedance, the diaphragm is still the most significant part of the equation.

We know that extremely low noise can be achieved by using undamped diaphragms, which in turn needs electronic frequency response compensation. The absence of data in this respect leaves me quite dubious.

An aggravating factor is that only a small part of the diaphragm is taken into account; since the S/N ratio decreases by 3dB every time the surface is halved. I'm not familiar enough with optical microphones, but a I doubt a laser ray has the capability to sample the whole diaphragm area. Conventional condenser mics do that natively.

Lack of comparative data leaves me only speculating.

--

Best Regards,

Jules Ryckebusch

214 399 0931

This came up on my readinglist today:

“?Researchers at Carnegie Mellon University have presented some remarkable audio from a new optical microphone system that uses cameras to see and reconstruct sonic vibrations. Remarkably, it can cleanly separate a single instrument playing in a group.”

This kind of sonic isolation is extremely difficult even for high-end audio microphones, so to be able to achieve it using nothing but two cameras and a laser? It feels a bit like black magic. But the results, which you can see in the video embedded at the end of this piece, are stunning.

Op zo 26 jun. 2022 om 13:36 schreef Jules Ryckebusch <ryckebusch@...>

I agree with Jerry and Tom. They are really comparing it to a laser microphone which is a single use case. This paper reads like a "Well we got it to work and there is slight numerical improvement in one aspect" As a tech thing it is great. As a Schoeps, Neumman, AKG, and Rode lose sleep at night thing? Not so much.

Jules

On Sun, Jun 26, 2022 at 6:16 AM Jerry Lee Marcel <jerryleemarcel@...> wrote:

Knowing that most of the noise is due to acoustic impedance, the diaphragm is still the most significant part of the equation.

We know that extremely low noise can be achieved by using undamped diaphragms, which in turn needs electronic frequency response compensation. The absence of data in this respect leaves me quite dubious.

An aggravating factor is that only a small part of the diaphragm is taken into account; since the S/N ratio decreases by 3dB every time the surface is halved. I'm not familiar enough with optical microphones, but a I doubt a laser ray has the capability to sample the whole diaphragm area. Conventional condenser mics do that natively.

Lack of comparative data leaves me only speculating.

--

Best Regards,

Jules Ryckebusch

214 399 0931

I agree with Jerry and Tom. They are really comparing it to a laser microphone which is a single use case. This paper reads like a "Well we got it to work and there is slight numerical improvement in one aspect" As a tech thing it is great. As a Schoeps, Neumman, AKG, and Rode lose sleep at night thing? Not so much.

Jules

On Sun, Jun 26, 2022 at 6:16 AM Jerry Lee Marcel <jerryleemarcel@...> wrote:

Knowing that most of the noise is due to acoustic impedance, the diaphragm is still the most significant part of the equation.

We know that extremely low noise can be achieved by using undamped diaphragms, which in turn needs electronic frequency response compensation. The absence of data in this respect leaves me quite dubious.

An aggravating factor is that only a small part of the diaphragm is taken into account; since the S/N ratio decreases by 3dB every time the surface is halved. I'm not familiar enough with optical microphones, but a I doubt a laser ray has the capability to sample the whole diaphragm area. Conventional condenser mics do that natively.

Lack of comparative data leaves me only speculating.

--

Best Regards,

Jules Ryckebusch

214 399 0931

Hello,

I'm definitely a tube mic guy, but this article on quantum microphones certainly caught my eye (probably great for room mics when heavily compressed!).


Here's a very short blurb.? The abstract of the paper featured in the article has lots more detail.? Sorry to say, you might have to sign up for a "free trial period to read it".

"A quantum can record human speech better than an equivalent classical version, and it could also be adapted for high-resolution biological imaging. Standard microphones detect the vibrations from sound and convert them into an equivalent electrical signal. Quantum versions should potentially be able to do the same thing, but create a clearer recording because of the , in which particles – such as photons of flight – have linked properties. This potential exists because pairs of entangled photons can measure..."

Regards,

Terry

I successfully paired it with this capsule -- See photo of all brass capsule.

I understand the difference between FET and FET-less capsules and your proposed working definition of "true condenser" is what I intended by the term.

To connect an externally polarised capsule you connect one side to the input of the fet and the other to the polarisation voltage.

Board #4 has two transistors instead of the single FET of a KM-84. I'm guessing the second transistor is an emitter follower for driving a??2:1?ratio transformer, which is cheaper to manufacture than a high quality 8:1 transformer as used by Neumann. It appears to have two 1Gohm resistors, as used in a KM-84 polarization circuit with K67, K87, K47, and K12 style "true condenser" capsules. I haven't seen one of these boards myself. Guessing at the circuit from the photo.

Good Morning Gentlemen!

To Jules -- I follow the gist of your commentary. Obviously I need to learn more about polarizing voltage versus phantom power. I would appreciate leads to the homework I must perform. I am not averse to reading, as I do not expect you guys to tell me everything on the forum. Much appreciated - I believe there is a LOT of buckshot in that one shell (reply) and this is the tip of the old iceberg. :-)

To Thet -- I am beginning to understand how much I do not yet know here. I attach photos of the two capsules in question.
The 1-inch item is described here:

I understand the difference between FET and FET-less capsules and your proposed working definition of "true condenser" is what I intended by the term.

And, I believe we can now get down to the THE NITTY GRITTY . . . Um ... ahem ... er ... I did not purchase both boards for either the OPA Alice or the eBay boards under scrutiny. And given the trend of the discussion ... ahem ... I now wonder whether I should have purchased both boards. After reading Jules articles on www.Indestructibles.com, and a website by an UK mic maven www.audioimprov.com, I was under the impression the OPA Alice board could be used alone, as a substitute for the ubiquitous BM-800 boards. I extrapolated that presumption and ordered just the one board in question from an eBay seller, "hoping" (blithely presuming, actually) it is the equivalent of the OPA Alice board.

To Henry -- Please see above.

So, I now wonder whether I failed to purchase a complete kit for the larger, 34 mm capsules.

I purchased another board on eBay that seems to work well on its own. See photos - board with yellow transformer.

I successfully paired it with this capsule -- See photo of all brass capsule.

I have, therefor had rather mixed results, but I now wonder whether I have, as one of you put it, mixed my apples with my oranges, because I do not (yet) fully understand how the bias thing works.

Gee - I hope this makes sense. It appears I started swimming before I fully learned how! THANK YOU for any further insight you can provide. Happy trails to all. James