amdx wrote:
===========

** Fuck off Mikek

On Sunday, 19 December 2021 at 12:00:55 UTC, Jasen Betts wrote:
> On 2021-12-19, amdx <am...@knology.net> wrote:
> > On 12/19/2021 4:52 AM, John Walliker wrote:
> >> On Sunday, 19 December 2021 at 09:31:32 UTC, amdx wrote:
> >>> On 12/18/2021 11:13 PM, Phil Allison wrote:
> >>>> amdx wrote:
> >>>> ===========
> >>>>>>>>> Another question, what is the best approach to paralleling multiple
> >>>>>>>>> electret mics together for maximum amplitude from each?
> >>>>>>>>>
> >>>>>>>> ** Connect each mic to a small, step down transformer and wire the secondaries in series.
> >>>>>>>>
> >>>>>>>> The signals from you mics will not be in-phase so will not add in a simple way.
> >>>>>>>>
> >>>>>>>>
> >>>>>>> I have thought about signals of different frequencies adding and
> >>>>>>> subtracting, but don't they do that in air also?
> >>>>>>>
> >>>>>> ** How many angels can dance on the head of a pin ??
> >>>>>>
> >>>>>>
> >>>>> I don't believe in angels.
> >>>> ** Fuck off Mikek.
> >>>>
> >>> I ask questions, because I don't know the answers, I'm not sure why that pisses you off.
> >>> I don't know why you would get involved in a thread, if this is what happens.
> >>> Mikek
> >>>
> >>>
> >>> --
> >>> This email has been checked for viruses by Avast antivirus software.
> >>> https://www.avast.com/antivirus
> >> I may have missed it, but how many microphones do you intend to use?
> >>
> >> John
> >
> > It's possible I could use 22, IF, I put a mic on each resonant tube
> > 300Hz to 3000Hz.
> >
> > Or I may find a way to use just one. At this time, I find I need a
> > velocity type microphone
> >
> > to mount on a 1/2 wavelength open end tube. The only velocity type
> > microphone I find is a ribbon microphone,
> >
> > I don't expect to use a ribbon microphone. This 1964 design requires a
> > different build because most newer mics
> >
> > operate on pressure not velocity, like the mic that the design used.
> >
> a pressure microphome will still give a signal, but if mounted at the
> closed end the signal will be stronger.
>
> --
> Jasen.

I have looked at the original article and I really struggle to understand
how it could work as intended.
The microphone is glued into a funnel which appears to be sealed at
the back. So there is no rear port. Most shotgun mics rely on
cancellation between the front and back ports to give front-back
directivity.

John

On 12/19/2021 5:46 AM, Jasen Betts wrote:
> On 2021-12-19, amdx <amdx@knology.net> wrote:
>> On 12/19/2021 4:52 AM, John Walliker wrote:
>>> On Sunday, 19 December 2021 at 09:31:32 UTC, amdx wrote:
>>>> On 12/18/2021 11:13 PM, Phil Allison wrote:
>>>>> amdx wrote:
>>>>> ===========
>>>>>>>>>> Another question, what is the best approach to paralleling multiple
>>>>>>>>>> electret mics together for maximum amplitude from each?
>>>>>>>>>>
>>>>>>>>> ** Connect each mic to a small, step down transformer and wire the secondaries in series.
>>>>>>>>>
>>>>>>>>> The signals from you mics will not be in-phase so will not add in a simple way.
>>>>>>>>>
>>>>>>>>>
>>>>>>>> I have thought about signals of different frequencies adding and
>>>>>>>> subtracting, but don't they do that in air also?
>>>>>>>>
>>>>>>> ** How many angels can dance on the head of a pin ??
>>>>>>>
>>>>>>>
>>>>>> I don't believe in angels.
>>>>> ** Fuck off Mikek.
>>>>>
>>>> I ask questions, because I don't know the answers, I'm not sure why that pisses you off.
>>>> I don't know why you would get involved in a thread, if this is what happens.
>>>> Mikek
>>>>
>>>>
>>>> --
>>>> This email has been checked for viruses by Avast antivirus software.
>>>> https://www.avast.com/antivirus
>>> I may have missed it, but how many microphones do you intend to use?
>>>
>>> John
>>  It's possible I could use 22, IF, I put a mic on each resonant tube
>> 300Hz to 3000Hz.
>>
>> Or I may find a way to use just one. At this time, I find I need a
>> velocity type microphone
>>
>> to mount on a 1/2 wavelength open end tube. The only velocity type
>> microphone I find is a ribbon microphone,
>>
>> I don't expect to use a ribbon microphone. This 1964 design requires a
>> different build because most newer mics
>>
>> operate on pressure not velocity, like the mic that the design used.
>>
> a pressure microphome will still give a signal, but if mounted at the
> closed end the signal will be stronger.

I've tested a few closed end 1/4 wavelength tubes mic'ed at closed end, with different diameters.
Preliminarily I don't see that diameter affects amplitude, nor is there any difference in amplitude
between, an end mic'ed 1/4 wavelength tube and a 1/2 wavelength center mounted mic'ed tube.
I want to get outside where I can get more distance between source and mic to see if tube diameter
affects the 3db off axis amplitude. The author of the original shotgun microphone used 3/8" O.D tubing.
I have used 1-3/8" I.D down to 1/2" I.D.
Looks like a rainy day, I use it to find/build an audio preamp/amp to work at longer distances.
Mikek

On 12/19/2021 7:39 AM, John Walliker wrote:
> On Sunday, 19 December 2021 at 12:00:55 UTC, Jasen Betts wrote:
>> On 2021-12-19, amdx <am...@knology.net> wrote:
>>> On 12/19/2021 4:52 AM, John Walliker wrote:
>>>> On Sunday, 19 December 2021 at 09:31:32 UTC, amdx wrote:
>>>>> On 12/18/2021 11:13 PM, Phil Allison wrote:
>>>>>> amdx wrote:
>>>>>> ===========
>>>>>>>>>>> Another question, what is the best approach to paralleling multiple
>>>>>>>>>>> electret mics together for maximum amplitude from each?
>>>>>>>>>>>
>>>>>>>>>> ** Connect each mic to a small, step down transformer and wire the secondaries in series.
>>>>>>>>>>
>>>>>>>>>> The signals from you mics will not be in-phase so will not add in a simple way.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>> I have thought about signals of different frequencies adding and
>>>>>>>>> subtracting, but don't they do that in air also?
>>>>>>>>>
>>>>>>>> ** How many angels can dance on the head of a pin ??
>>>>>>>>
>>>>>>>>
>>>>>>> I don't believe in angels.
>>>>>> ** Fuck off Mikek.
>>>>>>
>>>>> I ask questions, because I don't know the answers, I'm not sure why that pisses you off.
>>>>> I don't know why you would get involved in a thread, if this is what happens.
>>>>> Mikek
>>>>>
>>>>>
>>>>> --
>>>>> This email has been checked for viruses by Avast antivirus software.
>>>>> https://www.avast.com/antivirus
>>>> I may have missed it, but how many microphones do you intend to use?
>>>>
>>>> John
>>> It's possible I could use 22, IF, I put a mic on each resonant tube
>>> 300Hz to 3000Hz.
>>>
>>> Or I may find a way to use just one. At this time, I find I need a
>>> velocity type microphone
>>>
>>> to mount on a 1/2 wavelength open end tube. The only velocity type
>>> microphone I find is a ribbon microphone,
>>>
>>> I don't expect to use a ribbon microphone. This 1964 design requires a
>>> different build because most newer mics
>>>
>>> operate on pressure not velocity, like the mic that the design used.
>>>
>> a pressure microphome will still give a signal, but if mounted at the
>> closed end the signal will be stronger.
>>
>> --
>> Jasen.
> I have looked at the original article and I really struggle to understand
> how it could work as intended.
> The microphone is glued into a funnel which appears to be sealed at
> the back. So there is no rear port. Most shotgun mics rely on
> cancellation between the front and back ports to give front-back
> directivity.
>
> John
>
>
I question whether the 1/2 wavelength tube are actually sealed.
I don't think the author took great effort to seal around the funnel,
but, I think the 36 other tubes pointing to the front are an open end to
each of the other resonant tubes. (?)
If the tubes were sealed, from what I have learned about pressure and velocity,
nodes and antinodes, I also don't see how it would work.
Mikek