Microphones in parallel to reduce noise

Not exactly frequency shaping, but probably time delay via networks. You need delay to do beam forming. It is easier in radar since the bandwidth is narrow. For audio, you are much better off using DSP techniques where delay comes for free in the sampling.

I looked into doing a product with multiple microphones years ago. The idea was not to do beam forming, which merely steers the signal, but zone forming. It is possible with DSP to narrow the pickup to a zone rather than have the beam go out to infinity.

The problem with beam forming is it is a patent mine field. As you probably know, half the patents litigated are proven to be invalid, but the cost to litigate makes developing the project unfeasible for the small investor. Even a large Japanese firm I was dealing with didn't want to do it.

It would be interesting to see how Polycom got their project to market.

Reply to
miso
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The issue is more related to ESD protection on the chip. You can make a very high impedance amplifier in CMOS, but it would be a touchy product in assembly. I don't recall running into a BICMOS with JFETs, but that would be a better technology.

Reply to
miso

Just don't try to seperate them. You know what happens when you try to divide zero by zero.

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Offworld checks no longer accepted!
Reply to
Michael A. Terrell

ere ought to

ries

Nope, My experience is with 1980s audio when every open channel was a problem. I'm glad to admit that. I'm a laser/electro-optics guy.

Any specfic AES paper?

Steve

Reply to
osr

Crazy idea, Is there anyway to add them in series?

George H.

Reply to
George Herold

Phil, you're great! How much does a good Dynamic mic cost and who makes it? Say in the $10 - $20 range.

George H.

Reply to
George Herold

Is there any mic switching or multiple acquisition paths? A good conference mic would be directional in a bunch of directions and select the dominant-signal mic, excluding the noise from other directions.

John

Reply to
John Larkin

They could just be in parallel. That would work if they were raw electrets or if they were the more common electret+jfet.

But it sounds more complicated.

John

Reply to
John Larkin

Wow, a trio of DimBulbs. We've hit the mother load!

Reply to
krw

You get a DimBulb Donkey?

Reply to
krw

"George = Herold the Hopeless"

** The topic was mic *inserts*.

Do your own Googling.

... Phil

Reply to
Phil Allison

"krw"

** Totally stupid bullshit.

Why don't ya go drop dead -

you VILE LYING pile of sub human GARBAGE.

.... Phil

Reply to
Phil Allison

Or a black hole.

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Offworld checks no longer accepted!
Reply to
Michael A. Terrell

That would be "mother lode" actually. Can't you even spell ?

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You're the DimBulb here.

Dynamic and Electret have specific and very different scientific meanings and are constructed totally differently.

You may have seen an electret mic *marketed* as dynamic by some bunch of half-wits but that doesn't make it valid.

Graham

Reply to
Eeyore

So, you're as thick as 'krw' are you ?

Graham

Reply to
Eeyore

In this instance to do what was required would require 10 capsules of whatever type - you wally.

Graham

Reply to
Eeyore

On a sunny day (Thu, 17 Dec 2009 02:14:30 +0000) it happened Eeyore wrote in :

Dynamic mikes have a heavier diafragm, and because of that are less sensitive. So you may gain at one point, but have less signal to process, still more noise. This is *my* view, IIRC Phil has a different idea about that.

Reply to
Jan Panteltje

"Jan Panteltje is a Wog Wanker "

** Yaaaaaawwwwwwnnnnnnnnnnnnnnnnnnnnnnnnnnnn.....

** Supposition - not fact.

Spend a few hours ( or several years in my case) studying makers spec sheets or better still the real things.

Shut the FUCK UP till you have !

Wog IDIOT !!!!!

..... Phil

Reply to
Phil Allison

On a sunny day (Fri, 18 Dec 2009 01:16:36 +1100) it happened "Phil Allison" wrote in :

I have tried the dynamics. And the electrets.

Well, how about studying your prescription?

LOL

Reply to
Jan Panteltje

Sure, if you transformer-couple the outputs; use 9 transformers to put ten in series. The individual units need filtered DC on the power terminal to bias 'em, though, and there's DC on the outputs.

I'm not happy paralleling the (FET) outputs; seems like the DC levels would interact poorly. One could, however, use a low-Z input, high-Z output amplifier on each unit (grounded base transistor) and just tie all the outputs (collectors) together, with suitable bias.

More troubling, the multiple small microphones are a phased array of elements; you'd want to form the array with respect to the desired microphone directional gain (which will be frequency-dependent).

Reply to
whit3rd

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