Meaning of this Microphone spec...

[John Larkin]

On Sun, 29 Nov 2020 11:35:51 -0600, amdx <amdx@knology.net> wrote:

On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <amdx@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing Voltage
   (3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows it down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.

                   Mikek

It looks great to me.

--

John Larkin Highland Technology, Inc trk

The cork popped merrily, and Lord Peter rose to his feet.
\"Bunter\", he said, \"I give you a toast. The triumph of Instinct over Reason\"

 

[Lasse Langwadt Christensen]

søndag den 29. november 2020 kl. 18.36.02 UTC+1 skrev amdx:

On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <am...@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing Voltage
(3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows it down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.

compared to what?

 

[server]

On Tue, 1 Dec 2020 12:02:16 -0800 (PST), Phil Allison
<pallison49@gmail.com> wrote:

Some Jerk-Off called Larkin puked:

===============================

(snip entire context)

One could put a lot of tiny MEMS or electret mikes on one PC board. I
wonder what could be done with that. And maybe a bit of DSP? A
phased-array microphone?


** Could a more irrelevant or meaningless reply be imagined?


.... Phil

People with no imagination might think so.



--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

 

[server]

On Wed, 02 Dec 2020 08:51:42 +0200, upsidedown@downunder.com wrote:

On Tue, 01 Dec 2020 08:10:46 -0800, jlarkin@highlandsniptechnology.com
wrote:


One could put a lot of tiny MEMS or electret mikes on one PC board. I
wonder what could be done with that. And maybe a bit of DSP? A
phased-array microphone?

Thanks to the small dimensions of these microphone capsules. all four
microphones in Ambisonic https://en.wikipedia.org/wiki/Ambisonics
tetrahedron can be put into a single point even at 20 kHz (wavelength
16 mm).

The signals can be used to produce the B-format (W, x, y, z) channels,
which can then be used to produce different radiation patterns, such
as cardioid and aim it into different directions, either in real time
or in post processing.

Right. The array can be aimed. S/N improves with more mikes, too.

The mikes could be arranged in a horizontal pattern too, for 360
degree aiming in the horizontal plane. The tiny mikes could be treated
as point pressure sensors. Or even 3D arrays.

Imagine a 3D video display, showing sound waves traveling through the
array, and projected sources.



--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

 

[amdx]

On 11/29/2020 1:18 PM, Lasse Langwadt Christensen wrote:

søndag den 29. november 2020 kl. 18.36.02 UTC+1 skrev amdx:
On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <am...@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing Voltage
(3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows it down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.
compared to what?

Maybe this one,

> https://www.jlielectronics.com/content/JLI-61A.pdf

I\'m far from an expert, and haven\'t seen enough spec sheets to know good
numbers, but,

I don\'t think the Mouser unit is very sensitive and the response is not
flat at the high end.

But I have 10, so, I\'ll see what they do and compare to the JLI unit if
I get some.

 If I run it on 9V instead of 3V, do I just raise the 2.2kΩ to 6.8kΩ?

                                                Mikek



--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

[server]

On Wed, 02 Dec 2020 07:39:08 -0800, jlarkin@highlandsniptechnology.com
wrote:

On Wed, 02 Dec 2020 08:51:42 +0200, upsidedown@downunder.com wrote:

On Tue, 01 Dec 2020 08:10:46 -0800, jlarkin@highlandsniptechnology.com
wrote:


One could put a lot of tiny MEMS or electret mikes on one PC board. I
wonder what could be done with that. And maybe a bit of DSP? A
phased-array microphone?

Thanks to the small dimensions of these microphone capsules. all four
microphones in Ambisonic https://en.wikipedia.org/wiki/Ambisonics
tetrahedron can be put into a single point even at 20 kHz (wavelength
16 mm).

The signals can be used to produce the B-format (W, x, y, z) channels,
which can then be used to produce different radiation patterns, such
as cardioid and aim it into different directions, either in real time
or in post processing.

Right. The array can be aimed. S/N improves with more mikes, too.

The mikes could be arranged in a horizontal pattern too, for 360
degree aiming in the horizontal plane. The tiny mikes could be treated
as point pressure sensors. Or even 3D arrays.

The sound field microphone
https://en.wikipedia.org/wiki/Soundfield_microphone is of course 3D,
containing also the height information.

One problem with 3D sound reproduction is the layout of speakers. Some
use two speakers down front, two speakers up front and two speakers in
the back.

Imagine a 3D video display, showing sound waves traveling through the
array, and projected sources.

It would interesting to have a WW I aerial combat movie or game, such
as Sopwith Camel against Fokkers with sound sources from all
directions .

 

[piglet]

On 29/11/2020 8:32 pm, amdx wrote:

On 11/29/2020 1:18 PM, Lasse Langwadt Christensen wrote:
søndag den 29. november 2020 kl. 18.36.02 UTC+1 skrev amdx:
On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <am...@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing
Voltage
(3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows it
down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.
compared to what?

Maybe this one,

https://www.jlielectronics.com/content/JLI-61A.pdf

I\'m far from an expert, and haven\'t seen enough spec sheets to know good
numbers, but,

I don\'t think the Mouser unit is very sensitive and the response is not
flat at the high end.

But I have 10, so, I\'ll see what they do and compare to the JLI unit if
I get some.

 If I run it on 9V instead of 3V, do I just raise the 2.2kΩ to 6.8kΩ?

                                                Mikek

The first you posted and asked about is better (apart from the dip at HF
end). The second part is noisier and less sensitive. The first one
sensitivity is -24dB versus the second one -35dB. The first one S/N is
80dB the second is 62dB.

Do you care that much about the dip around 18KHz?

piglet

 

[Michael Kellett]

On 29/11/2020 20:32, amdx wrote:

On 11/29/2020 1:18 PM, Lasse Langwadt Christensen wrote:
søndag den 29. november 2020 kl. 18.36.02 UTC+1 skrev amdx:
On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <am...@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing
Voltage
(3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows it
down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.
compared to what?

Maybe this one,

https://www.jlielectronics.com/content/JLI-61A.pdf

I\'m far from an expert, and haven\'t seen enough spec sheets to know good
numbers, but,

I don\'t think the Mouser unit is very sensitive and the response is not
flat at the high end.

But I have 10, so, I\'ll see what they do and compare to the JLI unit if
I get some.

 If I run it on 9V instead of 3V, do I just raise the 2.2kΩ to 6.8kΩ?

                                                Mikek

Since it says the rated voltage is 3V I think you might be pushing your
luck with 9V. They don\'t state a maximum voltage so you could ask.

MK

 

[piglet]

On 29/11/2020 9:31 pm, Michael Kellett wrote:

On 29/11/2020 20:32, amdx wrote:
On 11/29/2020 1:18 PM, Lasse Langwadt Christensen wrote:
søndag den 29. november 2020 kl. 18.36.02 UTC+1 skrev amdx:
On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <am...@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing
Voltage
(3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows it
down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.
compared to what?

Maybe this one,

https://www.jlielectronics.com/content/JLI-61A.pdf

I\'m far from an expert, and haven\'t seen enough spec sheets to know
good numbers, but,

I don\'t think the Mouser unit is very sensitive and the response is
not flat at the high end.

But I have 10, so, I\'ll see what they do and compare to the JLI unit
if I get some.

  If I run it on 9V instead of 3V, do I just raise the 2.2kΩ to 6.8kΩ?

                                                 Mikek



Since it says the rated voltage is 3V I think you might be pushing your
luck with 9V. They don\'t state a maximum voltage so you could ask.

MK

The PUI (first one) data sheet does spec supply voltage as 1-10V so 9V
should be OK. After all is probably just the drain of a small jfet.

piglet

 

[Jeff Liebermann]

On Sun, 29 Nov 2020 21:31:22 +0000, Michael Kellett <mk@mkesc.co.uk>
wrote:

 If I run it on 9V instead of 3V, do I just raise the 2.2k? to 6.8k??

                                                Mikek

Since it says the rated voltage is 3V I think you might be pushing your
luck with 9V. They don\'t state a maximum voltage so you could ask.
MK

9V should work.

The PUI Audio mic from Mouser is rated 1 - 10 VDC. See spec sheet at:
<https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf>
<https://www.mouser.com/new/pui-audio/pui-hd-condenser-microphones/>

The JLI mic from JLI is rate at 10VDC maxiumum. See the
specifications section at:
<https://www.jlielectronics.com/content/JLI-61A.pdf>

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Michael Kellett]

On 29/11/2020 22:05, Jeff Liebermann wrote:

On Sun, 29 Nov 2020 21:31:22 +0000, Michael Kellett <mk@mkesc.co.uk
wrote:

 If I run it on 9V instead of 3V, do I just raise the 2.2k? to 6.8k??

                                                Mikek

Since it says the rated voltage is 3V I think you might be pushing your
luck with 9V. They don\'t state a maximum voltage so you could ask.
MK

9V should work.

The PUI Audio mic from Mouser is rated 1 - 10 VDC. See spec sheet at:
https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
https://www.mouser.com/new/pui-audio/pui-hd-condenser-microphones/

The JLI mic from JLI is rate at 10VDC maxiumum. See the
specifications section at:
https://www.jlielectronics.com/content/JLI-61A.pdf

Can\'t think how I missed that. It\'s late here !
MK

 

[Phil Allison]

piglet wrote:
===========

The first you posted and asked about is better (apart from the dip at HF
end). The second part is noisier and less sensitive. The first one
sensitivity is -24dB versus the second one -35dB. The first one S/N is
80dB the second is 62dB.

** Quoting s/n is not very useful without a reference.
1Pa = 94dB SPL
So the first mic has a background noise equivalent 14 dB SPL.
If true, that is an exceptional number for a small electret.
Puts it right in the middle of the best available mics.

> Do you care that much about the dip around 18KHz?

** Likely not for real, never seen a small electret do that before.
Usually, the response rises at 16kHz due to \"pressure doubling on the surface of the diaphragm.

..... Phil

 

[Rick C]

On Sunday, November 29, 2020 at 3:32:20 PM UTC-5, amdx wrote:

On 11/29/2020 1:18 PM, Lasse Langwadt Christensen wrote:
søndag den 29. november 2020 kl. 18.36.02 UTC+1 skrev amdx:
On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <am...@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing Voltage
(3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows it down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.
compared to what?
Maybe this one,

https://www.jlielectronics.com/content/JLI-61A.pdf

I\'m far from an expert, and haven\'t seen enough spec sheets to know good
numbers, but,

I don\'t think the Mouser unit is very sensitive and the response is not
flat at the high end.

But I have 10, so, I\'ll see what they do and compare to the JLI unit if
I get some.

If I run it on 9V instead of 3V, do I just raise the 2.2kΩ to 6.8kΩ?

The PUI unit that you call \"Mouser\" is -24 dB relative to 1V/Pa. The JLI unit is -35 dB. I assume you understand dB, right?

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[Cursitor Doom]

On Sun, 29 Nov 2020 11:35:51 -0600, amdx <amdx@knology.net> wrote:

On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <amdx@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing Voltage
   (3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows it down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.

Depends what you want to use it for! Not much use for high quality
music recording at any rate.

 

[John Larkin]

On Mon, 30 Nov 2020 00:32:02 +0000, Cursitor Doom <cd@noreply.com>
wrote:

On Sun, 29 Nov 2020 11:35:51 -0600, amdx <amdx@knology.net> wrote:

On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <amdx@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing Voltage
   (3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows it down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.

Depends what you want to use it for! Not much use for high quality
music recording at any rate.

Why not?

--

John Larkin Highland Technology, Inc trk

The cork popped merrily, and Lord Peter rose to his feet.
\"Bunter\", he said, \"I give you a toast. The triumph of Instinct over Reason\"

 

[Lasse Langwadt Christensen]

mandag den 30. november 2020 kl. 01.32.09 UTC+1 skrev Cursitor Doom:

On Sun, 29 Nov 2020 11:35:51 -0600, amdx <am...@knology.net> wrote:
On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <am...@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing Voltage
(3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows it down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.
Depends what you want to use it for! Not much use for high quality
music recording at any rate.

look up the frequency response of an SM57 and SM58
a helluva lot of music has been recorded and performed with those two

 

[boB]

On Sun, 29 Nov 2020 14:32:10 -0600, amdx <amdx@knology.net> wrote:

On 11/29/2020 1:18 PM, Lasse Langwadt Christensen wrote:
søndag den 29. november 2020 kl. 18.36.02 UTC+1 skrev amdx:
On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <am...@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing Voltage
(3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows it down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.
compared to what?

Maybe this one,

https://www.jlielectronics.com/content/JLI-61A.pdf

I\'m far from an expert, and haven\'t seen enough spec sheets to know good
numbers, but,

I don\'t think the Mouser unit is very sensitive and the response is not
flat at the high end.

But I have 10, so, I\'ll see what they do and compare to the JLI unit if
I get some.

 If I run it on 9V instead of 3V, do I just raise the 2.2k? to 6.8k??

                                                Mikek

Looks like they are both pretty good although the JLI- 61A is a back
electret which are usually very good.
As far as the high frequency rolloff, the JLI- 61A appears to stop
short of 20kHz so there might be something funny going on up there
right near 20kHz that they don\'t want to show ?

Panasonic makes similar back electret capsules that are pretty
amazing. I\'ve been using those for almost 40 years

 

[boB]

On Sun, 29 Nov 2020 16:54:47 -0800 (PST), Lasse Langwadt Christensen
<langwadt@fonz.dk> wrote:

mandag den 30. november 2020 kl. 01.32.09 UTC+1 skrev Cursitor Doom:
On Sun, 29 Nov 2020 11:35:51 -0600, amdx <am...@knology.net> wrote:
On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <am...@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing Voltage
(3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows it down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.
Depends what you want to use it for! Not much use for high quality
music recording at any rate.

look up the frequency response of an SM57 and SM58
a helluva lot of music has been recorded and performed with those two

These little electret mics (omnidirectional) work pretty darn well for
binaural music recording. Been using them for quite a while.

They aren\'t the best you can get but sure are small and very
inexpensive.

 

[amdx]

On 11/29/2020 3:27 PM, piglet wrote:

On 29/11/2020 8:32 pm, amdx wrote:
On 11/29/2020 1:18 PM, Lasse Langwadt Christensen wrote:
søndag den 29. november 2020 kl. 18.36.02 UTC+1 skrev amdx:
On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <am...@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing
Voltage
(3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows
it down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.
compared to what?

Maybe this one,

https://www.jlielectronics.com/content/JLI-61A.pdf

I\'m far from an expert, and haven\'t seen enough spec sheets to know
good numbers, but,

I don\'t think the Mouser unit is very sensitive and the response is
not flat at the high end.

But I have 10, so, I\'ll see what they do and compare to the JLI unit
if I get some.

  If I run it on 9V instead of 3V, do I just raise the 2.2kΩ to 6.8kΩ?

                                                 Mikek




The first you posted and asked about is better (apart from the dip at
HF end). The second part is noisier and less sensitive. The first one
sensitivity is -24dB versus the second one -35dB. The first one S/N is
80dB the second is 62dB.

Do you care that much about the dip around 18KHz?

piglet

I roll off pretty fast over 4kHz! I can hear the guys fine at breakfast,
but have selective hearing for my wife.

I had a hearing test and the audiologist said getting hearing aids would
be a waste.

Mikek


--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

[amdx]

On 11/29/2020 9:34 PM, boB wrote:

On Sun, 29 Nov 2020 14:32:10 -0600, amdx <amdx@knology.net> wrote:

On 11/29/2020 1:18 PM, Lasse Langwadt Christensen wrote:
søndag den 29. november 2020 kl. 18.36.02 UTC+1 skrev amdx:
On 11/29/2020 11:22 AM, John Larkin wrote:
On Sun, 29 Nov 2020 10:46:53 -0600, amdx <am...@knology.net> wrote:

Looking at a electret condensor mic, it has a spec, \"Decreasing Voltage
(3VS to 2VS ) -3dB\"

What does that mean?
Gain drops as supply voltage drops. It would be even worse at 1 volt.

https://www.mouser.com/datasheet/2/334/AOM-5024L-HD-R-1219369.pdf
Also, the frequency response graph is labeled (db/1V) and shows it down
37 at 18kHz, that can\'t be down 37db at 18Khz.

What does that mean?
It\'s \"down\" about 12 dB at that notch, -25 to -37 dBv. Probably some
resonance.

Thanks all, doesn\'t seem like a great mic.
compared to what?
Maybe this one,

https://www.jlielectronics.com/content/JLI-61A.pdf
I\'m far from an expert, and haven\'t seen enough spec sheets to know good
numbers, but,

I don\'t think the Mouser unit is very sensitive and the response is not
flat at the high end.

But I have 10, so, I\'ll see what they do and compare to the JLI unit if
I get some.

 If I run it on 9V instead of 3V, do I just raise the 2.2k? to 6.8k??

                                                Mikek

Looks like they are both pretty good although the JLI- 61A is a back
electret which are usually very good.
As far as the high frequency rolloff, the JLI- 61A appears to stop
short of 20kHz so there might be something funny going on up there
right near 20kHz that they don\'t want to show ?

Panasonic makes similar back electret capsules that are pretty
amazing. I\'ve been using those for almost 40 years

I saw the JLI-61A recommended as a good replacement for the Panasonic WM-61A,
which is no longer available. The WM-61A was a popular mic for the DIYers for years.
Mikek



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