Re: [Sursound] A comparison of fifteen ambisonic microphones

[Jack Reynolds]

I feel I should apologise for saying Len is making himself look like a fool. 

That was uncalled for. 

The fact is, we chose the Zoom F8 because that is the most commonly used 
portable recorder, and is the recorder most likely to be used by owners of 
ambisonic microphones, due to the fact you can trim link the channel gains, the 
portability, sound quality and value for money. 

One microphone being less sensitive than another is not something needed to 
take into account as it is simply a fact of life. 

I would suggest the number of people who own a lower cost ambisonic microphone 
and also have access to a Millenia HV3 is vanishingly small and not 
representative of the real world use of the microphones we tested. 

The above is the reason we did not ‘overlook’ the low sensitivity of the 
Coresound Tetramic and Octomic we included in the comparison test. 

We used one of the recorders recommended by CoreSound on their website for use 
with the Octomic. 

The gain setting we used is on the edge of the linear EIN range of the F8 
preamp. 

If you repeated your F8 vs HV3 experiment at 38dB you would see an improvement 
over 30dB, hence my recommendation users of Octomics and F8s should avoid gain 
settings much below 40dB. 

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All mics were treated equally. 

The Millenia being a quieter, and much more expensive, preamp is not relevant 
to the study. 

I would greatly appreciate it if this discussion ended here and no further 
doubt is cast on the usefulness of the study. 

The noise improvement given by adding capsules is not relevant to this study. 

Listening to recordings of microphones is. 

Thank you. 

Jack Reynolds 

Sent from my iPhone

> On 10 Nov 2023, at 21:00, lenmoskow...@optonline.net wrote:
> 
> One additional comment:
> 
> At the very low end, the Zoom F8 is roughly 15 dB worse than the HV-316.
> 
> As you add gain on the F8, the errors get more and more audible.
> 
> 
> Len Moskowitz (mosko...@core-sound.com)
> Core Sound LLC
> www.core-sound.com
> Home of OctoMic and TetraMic
> 
> 
> -- Original Message --From: lenmoskowitz@optonline.netTo: 
> surso...@music.vt.eduSent: Friday, November 10, 2023 3:33 PMSubject: Re: A 
> comparison of fifteen ambisonic microphones
> When recording the self noise of an OctoMic using the
> Millennia Media HV-316 and Zoom F8 (both with 30 dB of
> gain), while the time domain noise levels look roughly equivalent,
> their noise spectraare quite different. That's what accounts for
> the degradation when using the Zoom F8.
> 
> At low frequencies (below 250 Hz), the F8 is five to ten dB worse
> than the HV-316. At higher frequencies (1 kHz to 20 kHz) it's around
> 5 dB worse.
> 
> You can see the noise spectra here:
> https://u.pcloud.link/publink/show?code=kZPTocVZ53w7P5SUFM5dsF0QpHlmvH6sPR8X
> 
> So the Zoom F8 penalizes mics that use low sensitivity capsules. It
> makes the self noise sound much worse than it really is.
> 
> The folks who ran the comparison test seem to have overlooked this.
> 
> 
> 
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Jack Reynolds]

Yes, we know that a $4000 preamp is better than a $1000 dollar preamp and 
recorder. 

What is your point?

Are you suggesting anyone who buys one of your mics should not use a Zoom F8?

That would appear to contradict the text on your website where you specifically 
recommend ….. the Zoom F8.

We also ran a second measurement at higher gain.,

What do you actually want, other than to hijack this study, again, and make it 
all about your specific microphones, noisy, low sensitivity, whatever. 

It needs to stop. 

I had to block you on Facebook for precisely this reason and you have been 
banned from several Facebook groups for similar offences. 

Please, just give it a rest. 

You are making yourself look like a fool. 

Jack

Sent from my iPhone

> On 10 Nov 2023, at 20:33, lenmoskow...@optonline.net wrote:
> 
> 
> When recording the self noise of an OctoMic using the 
> Millennia Media HV-316 and Zoom F8 (both with 30 dB of 
> gain), while the time domain noise levels look roughly equivalent, 
> their noise spectra are quite different. That's what accounts for 
> the degradation when using the Zoom F8.
>  
> At low frequencies (below 250 Hz), the F8 is five to  ten dB worse 
> than the HV-316. At higher frequencies (1 kHz to 20 kHz) it's around 
> 5 dB worse.
>  
> You can see the noise spectra here:
> https://u.pcloud.link/publink/show?code=kZPTocVZ53w7P5SUFM5dsF0QpHlmvH6sPR8X
>  
> So the Zoom F8 penalizes mics that use low sensitivity capsules. It 
> makes the self noise sound much worse than it really is.
>  
> The folks who ran the comparison test seem to have overlooked this.
> -- next part --
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[lenmoskowitz]

One additional comment:

At the very low end, the Zoom F8 is roughly 15 dB worse than the HV-316.

As you add gain on the F8, the errors get more and more audible.


Len Moskowitz (mosko...@core-sound.com)
Core Sound LLC
www.core-sound.com
Home of OctoMic and TetraMic


-- Original Message --From: lenmoskowitz@optonline.netTo: 
surso...@music.vt.eduSent: Friday, November 10, 2023 3:33 PMSubject: Re: 
A comparison of fifteen ambisonic microphones

When recording the self noise of an OctoMic using the
Millennia Media HV-316 and Zoom F8 (both with 30 dB of
gain), while the time domain noise levels look roughly equivalent,
their noise spectraare quite different. That's what accounts for
the degradation when using the Zoom F8.

At low frequencies (below 250 Hz), the F8 is five to ten dB worse
than the HV-316. At higher frequencies (1 kHz to 20 kHz) it's around
5 dB worse.

You can see the noise spectra here:
https://u.pcloud.link/publink/show?code=kZPTocVZ53w7P5SUFM5dsF0QpHlmvH6sPR8X

So the Zoom F8 penalizes mics that use low sensitivity capsules. It
makes the self noise sound much worse than it really is.

The folks who ran the comparison test seem to have overlooked this.



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Re: [Sursound] A comparison of fifteen ambisonic microphones

[lenmoskowitz]

When recording the self noise of an OctoMic using the 
Millennia Media HV-316 and Zoom F8 (both with 30 dB of 
gain), while the time domain noise levels look roughly equivalent, 
their noise spectra are quite different. That's what accounts for 
the degradation when using the Zoom F8.
 
At low frequencies (below 250 Hz), the F8 is five to  ten dB worse 
than the HV-316. At higher frequencies (1 kHz to 20 kHz) it's around 
5 dB worse.
 
You can see the noise spectra here:
https://u.pcloud.link/publink/show?code=kZPTocVZ53w7P5SUFM5dsF0QpHlmvH6sPR8X
 
So the Zoom F8 penalizes mics that use low sensitivity capsules. It 
makes the self noise sound much worse than it really is.
 
The folks who ran the comparison test seem to have overlooked this.
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Søren Bendixen]


Med venlig hilsen
Søren Bendixen
Audiotect
Composer/Sounddesigner/guitarist
(iPhone message)

> Den 10. nov. 2023 kl. 11.57 skrev Panos Kouvelis :
> 
> Although this thread is based on engineering and the scientific method, I
> would like to point out that all the developers of ambisonic microphones
> are doing a great job offering tools in a sector that is difficult for the
> industry to follow and more difficult for the average consumer to grasp.
> Not to mention that Ambisonics doesn't have the money backing and marketing
> power of commercial proprietary formats, besides the fact that it's a
> pretty elegant solution to spatial audio.
> 
> Everybody in the commercial immersive audio sector already has a difficult
> job, which sometimes seems like a dead end.
> 
> For us engineers and/or scientists, one decibel makes a difference, but we
> all should be proud and happy that we have so many nice toys to create,
> which is the ultimate cause.
> 
> I personally like to thank everybody who worked or shared input in this
> endeavor!
> 
> Major kudos! :-)
> 
> *Pan Athen*
> SoundFellas , *MediaFlake Ltd
> *
> Digital Media Services, Content, and Tools
> 
> 
>> On Fri, Nov 10, 2023 at 12:35 PM Jack Reynolds 
>> wrote:
>> 
>> Thanks Mark,
>> 
>> Much appreciated
>> 
>> I only wish Len wasn’t so defensive!
>> 
>> Cheers
>> 
>> Jack
>> 
>> Sent from my iPhone
>> 
>>> On 10 Nov 2023, at 01:18, Mark Thompson 
>> wrote:
>>> 
>>> Thanks Jack, I really appreciate the work you and your colleagues have
>> put together. It is a great resource for our community.
>>> 
>>> Kind regards,
>>> 
>>> Mark
>>> 
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Ralf R Radermacher]

Am 10.11.23 um 11:56 schrieb Panos Kouvelis:


I personally like to thank everybody who worked or shared input in this
endeavor!


Well roared, Lion, as they say here.

I only own a simple Zoom H3-VR but I've had loads of fun with it.

Ralf

--
Ralf R. Radermacher  -  Köln/Cologne, Germany
Blog  : http://the-real-fotoralf.blogspot.com
Audio : http://aporee.org/maps/projects/fotoralf
Fotos : https://www.fotocommunity.de/user_photos/770012

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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Panos Kouvelis]

Although this thread is based on engineering and the scientific method, I
would like to point out that all the developers of ambisonic microphones
are doing a great job offering tools in a sector that is difficult for the
industry to follow and more difficult for the average consumer to grasp.
Not to mention that Ambisonics doesn't have the money backing and marketing
power of commercial proprietary formats, besides the fact that it's a
pretty elegant solution to spatial audio.

Everybody in the commercial immersive audio sector already has a difficult
job, which sometimes seems like a dead end.

For us engineers and/or scientists, one decibel makes a difference, but we
all should be proud and happy that we have so many nice toys to create,
which is the ultimate cause.

I personally like to thank everybody who worked or shared input in this
endeavor!

Major kudos! :-)

*Pan Athen*
SoundFellas , *MediaFlake Ltd
*
Digital Media Services, Content, and Tools


On Fri, Nov 10, 2023 at 12:35 PM Jack Reynolds 
wrote:

> Thanks Mark,
>
> Much appreciated
>
> I only wish Len wasn’t so defensive!
>
> Cheers
>
> Jack
>
> Sent from my iPhone
>
> > On 10 Nov 2023, at 01:18, Mark Thompson 
> wrote:
> >
> > Thanks Jack, I really appreciate the work you and your colleagues have
> put together. It is a great resource for our community.
> >
> > Kind regards,
> >
> > Mark
> >
> ___
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Jack Reynolds]

Thanks Mark, 

Much appreciated

I only wish Len wasn’t so defensive!

Cheers

Jack 

Sent from my iPhone

> On 10 Nov 2023, at 01:18, Mark Thompson  wrote:
> 
> Thanks Jack, I really appreciate the work you and your colleagues have put 
> together. It is a great resource for our community.
> 
> Kind regards,
> 
> Mark
> 
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Mark Thompson]

Thanks Jack, I really appreciate the work you and your colleagues have put 
together. It is a great resource for our community.

Kind regards,

Mark

-Original Message-
From: Sursound  On Behalf Of Jack Reynolds
Sent: Friday, November 10, 2023 1:36 AM
To: Surround Sound discussion group 
Subject: Re: [Sursound] A comparison of fifteen ambisonic microphones

I’m not the sole author, but yes some of the recordings are made of microphones 
I have built, hence the name on the front of the mic and the naming of the 
audio files and my email address. I’m certainly not in any way trying to 
obscure that fact. 

It’s also important to point out that we have been absolutely impartial in our 
treatment of each microphone and Len is the only person who has pointed towards 
there being any problem with the test method or the results. 

We have taken his perceived errors into account by repeating the measurement at 
a higher gain, as Len suggested that was making his mics appear noisier than 
others due to low sensitivity. 

I am happy to rectify any problems anyone points out. 

I have just as much to lose as anyone else. 

If people listen to the recordings and hate the Reynolds mics, no problem.

The four of us did not undertake the comparison for any reason other than there 
not being this sort of resource available and hopefully people will find it 
useful and informative.

Jack Reynolds 

Sent from my iPhone

> On 9 Nov 2023, at 13:26, lenmoskow...@optonline.net wrote:
> 
> 
> In case it hasn't been clear, the author of this comparison is not 
> impartial. He is a small manufacturer of ambisonic mics, and has a conflict 
> of interest.
>  
>  
> Len Moskowitz (mosko...@core-sound.com) Core Sound LLC 
> www.core-sound.com <http://www.core-sound.com> Home of OctoMic and 
> TetraMic
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Jack Reynolds]

I’m not the sole author, but yes some of the recordings are made of microphones 
I have built, hence the name on the front of the mic and the naming of the 
audio files and my email address. I’m certainly not in any way trying to 
obscure that fact. 

It’s also important to point out that we have been absolutely impartial in our 
treatment of each microphone and Len is the only person who has pointed towards 
there being any problem with the test method or the results. 

We have taken his perceived errors into account by repeating the measurement at 
a higher gain, as Len suggested that was making his mics appear noisier than 
others due to low sensitivity. 

I am happy to rectify any problems anyone points out. 

I have just as much to lose as anyone else. 

If people listen to the recordings and hate the Reynolds mics, no problem.

The four of us did not undertake the comparison for any reason other than there 
not being this sort of resource available and hopefully people will find it 
useful and informative.

Jack Reynolds 

Sent from my iPhone

> On 9 Nov 2023, at 13:26, lenmoskow...@optonline.net wrote:
> 
> 
> In case it hasn't been clear, the author of this comparison is not impartial. 
> He is a 
> small manufacturer of ambisonic mics, and has a conflict of interest.
>  
>  
> Len Moskowitz (mosko...@core-sound.com)
> Core Sound LLC
> www.core-sound.com 
> Home of OctoMic and TetraMic
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[lenmoskowitz]

In case it hasn't been clear, the author of this comparison is not 
impartial. He is a 

small manufacturer of ambisonic mics, and has a conflict of interest.
 
 
Len Moskowitz (mosko...@core-sound.com)
Core Sound LLC
www.core-sound.com 
Home of OctoMic and TetraMic
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Jack Reynolds]

Hi Len,

The test has up until now been entirely focused on the B-Formats.

We are now talking about equivalent input noise, to determine whether your 
assertion regarding preamp gain affecting the performance of Tetra and Octomics 
was correct. 

I am assuming this is one of the ‘errors’ you refuse to clearly outline. 

We ran a second recording test at a higher gain level, which would appear to 
improve the noise performance, although the microphone’s self noise still 
dominates, as expected.  

It turns out the Zoom F8s preamps do get noisier below 40dB, by a very small 
amount as shown here:
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If we had made our test recordings at 15dB gain, the degradation would be 
audible, but thankfully we chose 38dB. 2dB below the linear range threshold. 

Now that we are talking about the equivalent input noise of preamps, at your 
insistence, the performance of a single capsule is absolutely relevant. Perhaps 
not for any of the other microphones in the test but since you have made 
assertions about your microphones not performing well with the F8 recorder,  
it’s extremely important that I address your concerns to avoid others doubting 
the usefulness of the study. 

One of your concerns appeared to be not recording at a high enough gain, due to 
the low sensitivity (-43dB) of the capsules you use and the noise performance 
of the F8 at certain gain settings. 

Your proposed solution is to use a $4000 preamp, which is perhaps not 
accessible to all and certainly not practical for field recording, which is 
where the majority of ambisonic microphones are used currently. 

Your other concern regarding your non-use of a particular Transound capsule 
(sold as JLI-120A-T -43dB) has been addressed and the PDF has been updated. The 
specs and appearance are remarkably similar to the capsules you use, so I’m 
sure you can understand how this error could have been made. 

If you could outline any other errors you think we may have made that would be 
greatly appreciated.

Thanks. 

Jack 


Sent from my iPhone

> On 4 Nov 2023, at 23:31, lenmoskow...@optonline.net wrote:
> Ambisonic microphones are always used as complete arrays and in B-format, so 
> that's the way they should be tested. Test results from single capsules are 
> irrelevant and misleading.
> 
> Single capsule testing doesn't include what the the A- to B-format encoder 
> modifies. Some encoders do very creative things.
> 
> So testing and evaluation should be done at B-format.
> 
> 
> Len Moskowitz (mosko...@core-sound.com)
> Core Sound LLC
> www.core-sound.com
> Home of OctoMic and TetraMic
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[lenmoskowitz]

Ambisonic microphones are always used as complete arrays and in 
B-format, so that's the way they should be tested. Test results from 
single capsules are irrelevant and misleading.


Single capsule testing doesn't include what the the A- to B-format 
encoder modifies. Some encoders do very creative things.


So testing and evaluation should be done at B-format.


Len Moskowitz (mosko...@core-sound.com)
Core Sound LLC
www.core-sound.com
Home of OctoMic and TetraMic
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Steven Boardman]

I have sen mkh40 and the rest of that series,  plus schoeps ccm cardioids
and OMNIs, along with the DPA4006.
The Dpa has the individual factory measurenent trace, which makes it more
useful as reference.

On Sat, 4 Nov 2023, 13:48 jack reynolds,  wrote:

> Thanks Steven.
>
> Do you know the quoted EIN specs for the RMEs?
>
> It might be fun to run an EIN test to see how the RME gains affect the
> preamp noisefloor, but I'm not sure the RME will be much quieter than the
> F8. They are pretty state of the art.
>
> The Millenia Len mentioned is a different beast but it costs four times as
> much as an F8 just for the preamps, so you'd hope it sounded better!
>
> I think an on axis recording of a single Tetra capsule would be worth
> having though, with pink noise at a measured SPL with an on axis DPA4006
> to compare to, rather than upright.
>
> Unless you have any high end cardioids? I've got a Sennheiser 8040 that
> could work, just as a known reference.
>
> J
>
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Fons Adriaensen]

On Sat, Nov 04, 2023 at 08:53:57AM +, Jack Reynolds wrote:
 
> The noise floor of the F8 mic pre is about about 10dB below the
> noise floor of a single tetramic capsule at 38dB gain at 1KHz.

How do you arrive at this figure ? 

> I also need to repeat the test with an 80 Ohm resistor load for
> a more accurate comparison with the Tetramic as the lower output
> impedance may have an effect on the noise floor at lower gains. 

At lower gains it won't have any effect. At higher gains there may
be some difference, but it will be small. Anyway the 'standard'
source impedance for an EIN measurement is 150 Ohm. 

Note that to find the real EIN, you also need to know the actual
gain of the preamp. That means you need to know the exact relation
between the analog input level and the digital level after the 
A/D converter since the latter is the one you actually measure.

The nomimal gain (10 to 75 dB on the F8) doesn't have any meaning,
not even if it happens to be the actual analog gain up the input
of the A/D converter.

The only 'gain' value that has real significance is the inverse
of the input level that results in a full scale digital signal
i.e. minus the X axis values in the example graph (which uses
dBV on both axes - I should have mentioned this).

Measuring that in a reliable way is not as easy as one could
imagine, there are lots of ways to get it wrong without being
aware of that. 

-- 
FA

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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Jack Reynolds]

Thanks Fons. 

This is exactly the kind of input we need. 

I ran an equivalent input noise test on the Zoom F8 last night, in the standard 
manner of soldering a 150 Ohm resistor across pins 2 and 3 of an XLR, for a 
dummy load. 

I can confirm relationship between input gain and mic pre noise floor is 
absolutely  linear between 55dB and 75dB of gain. I.e when you drop the gain 
5dB, the noise floor also drops 5dB. The relationships deteriorated by 1/3dB or 
so between 50dB and 40dB. 
Below 40dB gain the EIN performance deteriorates more severely.

I will update the doc in the gdrive folder to include a graph of this 
behaviour. 

The noise floor of the F8 mic pre is about about 10dB below the noise floor of 
a single tetramic capsule at 38dB gain at 1KHz.

At 58dB gain, the noise floors are 27dB apart, which is a considerable 
improvement, indicating that Tetramic and Zoom F8 owners, of which I imagine 
there are far more than tetramic and Millenia HV3 owners, should ensure they 
set their gains above 50dB to ensure best noise performance.  Using a Millenia 
pre, with 6dB better EIN than the F8 would be a further improvement. 

I will therefore use the 58dB tetramic recording as a more fair comparison in 
the test. 

I also need to repeat the test with an 80 Ohm resistor load for a more accurate 
comparison with the Tetramic as the lower output impedance may have an effect 
on the noise floor at lower gains. 

Thanks again for your input. This is the sort of discussion I hoped this study 
would produce. It’s easy to prove things one way or another when you have a 
starting point to work from. 

Just for the record, and for transparency, am I right in thinking you work 
closely with Len Moskowitz and CoreSound on the development of the Tetra VST A 
format to B Format encoder and calibration method?

Cheers

Jack


Sent from my iPhone

> On 3 Nov 2023, at 20:17, Fons Adriaensen  wrote:
> 
> On Fri, Nov 03, 2023 at 12:34:52PM +, Jack Reynolds wrote:
> 
>> I think the point here is we tested at two different pre-amps
>> gains, to eliminate that as a potential source of noise.
>> There was no difference in SNR, indicating the noise is generated
>> by the capsules and electronics, and not the preamp. 
> 
> Not having the required info (see below), I can't claim that the
> conclusion is wrong. But the reasoning behind it certainly is.
> 
> The Zoom F8 preamps have an EIN of -127 dBu(A) at maximum gain.
> Not bad, but not exceptional either. And that is the only spec
> we have regarding EIN.
> 
> It says NOTHING about EIN at other gain settings, in particular
> much lower ones. 
> 
> A well designed mic preamp will have its best EIN at the highest
> gain, and stay close to that value for a range of 15-20 dB below
> maximum gain. But for some the EIN will rise as soom as gain goes
> down.
> 
> As an example, have a look at 
> 
> 
> 
> This compares the measured EIN of two 8-channel preamps: the Aphex 
> 1788A and the Behringer Pro8, as a function of real gain.
> 
> At maximum gain the cheap Pro 8 ($200), is actually better than
> the Aphex ($4000). But not for long as gain is reduced.
> 
> The 65 dB gain range of the F8 is probably a combination of 
> passive attenuation, real analog gain, and (maybe) some 
> 'digital gain' as well. It's nowhere documented.
> 
> The gain used for the recordings was 38 dB, that is 37 dB
> below maximum. The real EIN at that setting is anybody's
> guess. Until it is actually measured, we just don't know.
> Even with 20 dB more gain, that is still 17 dB below max.
> 
> Making all the recordings at the same gain setting just
> doesn't make any sense. The correct way to do this is
> to use a sensible gain setting for each mic, and document
> that.
> 
> The available recordings do not include the raw (A-format)
> one for the Octomic with additional gain, and the Ambix
> ones do not have the 71 dB(SPL) noise signal. So there is
> no way to really compare them to anything else.
> 
> Ciao,
> 
> -- 
> FA
> 
> 
> ___
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Steven Boardman]

Thank you Len

Now I know it isn't that one.

Glad i didn't say 'certain', and never have. If you think 'I' have, then
I'm not sure why.

Miss quotes aside..

My point was that one doesn't have to open the mic. One could get info,
from the outside.

Appologies if this has been misconstrued.

If you want I could redo quite a few of these comparisons again with my RME
pre-amps.
Would they be the day you are speaking of?

Best regrds

Steven


On Fri, 3 Nov 2023, 17:19 ,  wrote:

> Steven Boardman wrote:
>
> > One doesn't need too, they are exposed.
> > Pretty sure they are Transound
> >
> > https://www.jlielectronics.com/transound/tsb-120ao
> >
> > I'm sure Len will correct me if wrong.
>
> "Pretty sure" is not the same as "I'm certain because the manufacturer
> told me."
>
> We don't discuss our capsules.
>
> If you go looking for capsules that look like what we use in TetraMic
> and OctoMic,
> you'll find products from at least 5 manufacturers, including Audix
> (used in their Micro
> series) and the ones from Transound that Jack and Steve were so certain
> about that they
> stated in their comparison that we used them in our products.
>
> Even then, they quoted the Transound noise specification wrong.
> ---
> It's worth mentioning that because both TetraMic and OctoMic are low
> sensitivity
> microphones, we recommend that our customers use the very quietest mic
> pre-amps.
> The difference in noise contributions between a Zoom F8 and a Millennial
> Media mic pre
> (for example) is like night and day. We know - we have them both here
> and have measured
> them.
>
>
> Len Moskowitz (mosko...@core-sound.com)
> Core Sound LLC
> www.core-sound.com
> Home of OctoMic and TetraMic
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here,
> edit account or options, view archives and so on.
>
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Fons Adriaensen]

On Fri, Nov 03, 2023 at 12:34:52PM +, Jack Reynolds wrote:

> I think the point here is we tested at two different pre-amps
> gains, to eliminate that as a potential source of noise.
> There was no difference in SNR, indicating the noise is generated
> by the capsules and electronics, and not the preamp. 

Not having the required info (see below), I can't claim that the
conclusion is wrong. But the reasoning behind it certainly is.

The Zoom F8 preamps have an EIN of -127 dBu(A) at maximum gain.
Not bad, but not exceptional either. And that is the only spec
we have regarding EIN.

It says NOTHING about EIN at other gain settings, in particular
much lower ones. 

A well designed mic preamp will have its best EIN at the highest
gain, and stay close to that value for a range of 15-20 dB below
maximum gain. But for some the EIN will rise as soom as gain goes
down.

As an example, have a look at 



This compares the measured EIN of two 8-channel preamps: the Aphex 
1788A and the Behringer Pro8, as a function of real gain.

At maximum gain the cheap Pro 8 ($200), is actually better than
the Aphex ($4000). But not for long as gain is reduced.

The 65 dB gain range of the F8 is probably a combination of 
passive attenuation, real analog gain, and (maybe) some 
'digital gain' as well. It's nowhere documented.

The gain used for the recordings was 38 dB, that is 37 dB
below maximum. The real EIN at that setting is anybody's
guess. Until it is actually measured, we just don't know.
Even with 20 dB more gain, that is still 17 dB below max.

Making all the recordings at the same gain setting just
doesn't make any sense. The correct way to do this is
to use a sensible gain setting for each mic, and document
that.

The available recordings do not include the raw (A-format)
one for the Octomic with additional gain, and the Ambix
ones do not have the 71 dB(SPL) noise signal. So there is
no way to really compare them to anything else.

Ciao,

-- 
FA


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Re: [Sursound] A comparison of fifteen ambisonic microphones

[lenmoskowitz]

Steven Boardman wrote:


One doesn't need too, they are exposed.
Pretty sure they are Transound

https://www.jlielectronics.com/transound/tsb-120ao

I'm sure Len will correct me if wrong.


"Pretty sure" is not the same as "I'm certain because the manufacturer 
told me."


We don't discuss our capsules.

If you go looking for capsules that look like what we use in TetraMic 
and OctoMic,
you'll find products from at least 5 manufacturers, including Audix 
(used in their Micro
series) and the ones from Transound that Jack and Steve were so certain 
about that they

stated in their comparison that we used them in our products.

Even then, they quoted the Transound noise specification wrong.
---
It's worth mentioning that because both TetraMic and OctoMic are low 
sensitivity
microphones, we recommend that our customers use the very quietest mic 
pre-amps.
The difference in noise contributions between a Zoom F8 and a Millennial 
Media mic pre
(for example) is like night and day. We know - we have them both here 
and have measured

them.


Len Moskowitz (mosko...@core-sound.com)
Core Sound LLC
www.core-sound.com
Home of OctoMic and TetraMic
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[David Stalling]

Must be the cardioid version of this Transound capsule, not the omni:

https://www.jlielectronics.com/microphone-capsules/jli-120a-t-43db/

There's also a similar one with slightly different sensitivity:

https://www.jlielectronics.com/microphone-capsules/jli-120a-t-45db/

Best,
David


On Fri, 3 Nov 2023 at 15:22, Steven Boardman 
wrote:

> One doesn't need too, they are exposed.
> Pretty sure they are Transound
>
> https://www.jlielectronics.com/transound/tsb-120ao
>
> I'm sure Len will correct me if wrong.
>
> Best
>
> Steven
>
> On Fri, 3 Nov 2023, 14:00 Ralf R Radermacher,  wrote:
>
> > Am 03.11.23 um 13:34 schrieb Jack Reynolds:
> > > Thanks Mark.
> > >
> > > I think the point here is we tested at two different pre-amps gains, to
> > eliminate that as a potential source of noise.
> > >
> > > There was no difference in SNR, indicating the noise is generated by
> the
> > capsules and electronics, and not the preamp.
> >
> > Has anyone ever had a look inside a Tetramic to see which capsule
> > they're using?
> >
> > Ralf
> >
> > --
> > Ralf R. Radermacher  -  Köln/Cologne, Germany
> > Blog  : http://the-real-fotoralf.blogspot.com
> > Audio : http://aporee.org/maps/projects/fotoralf
> > Fotos : https://www.fotocommunity.de/user_photos/770012
> >
> > ___
> > Sursound mailing list
> > Sursound@music.vt.edu
> > https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here,
> > edit account or options, view archives and so on.
> >
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Steven Boardman]

One doesn't need too, they are exposed.
Pretty sure they are Transound

https://www.jlielectronics.com/transound/tsb-120ao

I'm sure Len will correct me if wrong.

Best

Steven

On Fri, 3 Nov 2023, 14:00 Ralf R Radermacher,  wrote:

> Am 03.11.23 um 13:34 schrieb Jack Reynolds:
> > Thanks Mark.
> >
> > I think the point here is we tested at two different pre-amps gains, to
> eliminate that as a potential source of noise.
> >
> > There was no difference in SNR, indicating the noise is generated by the
> capsules and electronics, and not the preamp.
>
> Has anyone ever had a look inside a Tetramic to see which capsule
> they're using?
>
> Ralf
>
> --
> Ralf R. Radermacher  -  Köln/Cologne, Germany
> Blog  : http://the-real-fotoralf.blogspot.com
> Audio : http://aporee.org/maps/projects/fotoralf
> Fotos : https://www.fotocommunity.de/user_photos/770012
>
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here,
> edit account or options, view archives and so on.
>
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Ralf R Radermacher]

Am 03.11.23 um 13:34 schrieb Jack Reynolds:

Thanks Mark.

I think the point here is we tested at two different pre-amps gains, to 
eliminate that as a potential source of noise.

There was no difference in SNR, indicating the noise is generated by the 
capsules and electronics, and not the preamp.


Has anyone ever had a look inside a Tetramic to see which capsule
they're using?

Ralf

--
Ralf R. Radermacher  -  Köln/Cologne, Germany
Blog  : http://the-real-fotoralf.blogspot.com
Audio : http://aporee.org/maps/projects/fotoralf
Fotos : https://www.fotocommunity.de/user_photos/770012

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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Jack Reynolds]

Thanks Mark. 

I think the point here is we tested at two different pre-amps gains, to 
eliminate that as a potential source of noise.

There was no difference in SNR, indicating the noise is generated by the 
capsules and electronics, and not the preamp. 


Cheers

Jack

Sent from my iPhone

> On 3 Nov 2023, at 02:16, Mark Thompson  wrote:
> 
> Not sure if this helps the discussion or not, but I get the feeling this has 
> to do with the noise floor of the TetraMic capsules, and thought our own 
> independent observations may assist here. 
> 
> We have used the TetraMic for several years now, and like it. However, yes, 
> we have always had to increase pre-amp gain significantly (compared to other 
> microphone inputs) to get good input levels and as a result we meter high 
> noise levels on each capsule. It doesn't mean we've stopped using the 
> TetraMic, we just have to be mindful of this.
> 
> Kind regards,
> 
> Mark
> 
> -Original Message-
> From: Sursound  On Behalf Of Jack Reynolds
> Sent: Friday, November 3, 2023 7:10 AM
> To: Surround Sound discussion group 
> Subject: Re: [Sursound] A comparison of fifteen ambisonic microphones
> 
> Right. I see.
> 
> Thanks for the clarification. 
> 
> You pointed out various things you thought were errors, which no-one else 
> thought were errors, and we didn’t resolve anything at all.
> 
> I think it would be the right thing to do to outline your issues here to 
> prevent any further doubt being cast on the study. The ‘discussion’ on 
> Facebook was a farce and I would rather not repeat that here. 
> 
> As I remember you thought it was an unfair comparison because your mics are 
> less sensitive, and that meant they would need more input gain and that this 
> would unfairly increase the noise floor? 
> 
> We added a second recording at an increased gain setting and proved that 
> assertion to be incorrect. If a Zoom F8 mic preamp isn’t good enough….?
> 
> Your second assertion was that comparing to a KU100 was an unfair comparison 
> because a real binaural mic has real ITD. Your solution to this was to use 
> your favourite technique of bilateral ambisonics, which would mean finding 
> two of every mic, two recorders and twice the number of channels, which seems 
> like a waste of time effort to me. 
> That point raised some interesting discussion regarding higher order mics 
> resolving ITD better than lower order, and various approaches including first 
> decoding from ambisonics to SPS/T-Designs before binaural decoding as that 
> could potentially render ITD better. 
> We tried that and it didn’t sound any better… so we went back to a straight 
> ambisonics to binaural decode using Sadie ii KU100 HRTFs. Every mic treated 
> the same way, with no exception. 
> 
> What else was there?
> 
> I seem to remember you didn’t like the Schoeps ORTF3D array being in there 
> for comparison. I’m still not sure why. It’s a spaced 3D array, which will 
> obviously sound different from the near coincident arrays, but does that 
> matter?
> 
> What else was there?
> 
> I really do want to resolve this, in public, so we can draw a line under it 
> once and for all. 
> 
> Please just say what you think should be corrected, and why. 
> Also, if you can find a single person that agrees with your assertions I 
> would love to hear their opinion. 
> From the overly lengthy discussion on Facebook I don’t recall anyone agreeing 
> with you. Hence my position that there are in fact no errors in our method. 
> 
> The recordings are there for anyone to study. 
> If your assertion that there was an error in the process, it casts doubt on 
> our study and therefore the usefulness of the files. 
> 
> If you are unable to outline what those errors are - I can only assume there 
> are in fact no errors, and you are not acting in an honourable manner. 
> 
> Apologies to the other Sursounders if this is out of line. Any input would be 
> gratefully received.
> 
> Thanks
> 
> Jack 
> 
> 
> 
> Sent from my iPhone
> 
>> On 2 Nov 2023, at 19:24, lenmoskow...@optonline.net wrote:
>> 
>> We discussed the multiple errors in detail in our Facebook discussion.
>> 
>> That you didn't correct the comparison study, and actually added more 
>> incorrect information has made it clear that further discussion won't 
>> improve the outcome.
>> 
>> 
>> Len Moskowitz (mosko...@core-sound.com) Core Sound LLC 
>> www.core-sound.com Home of OctoMic and TetraMic
>> 
>> ___
>> Sursound mailing list
>> Sursound@music.vt.edu
>> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, 

Re: [Sursound] A comparison of fifteen ambisonic microphones

[Mark Thompson]

Not sure if this helps the discussion or not, but I get the feeling this has to 
do with the noise floor of the TetraMic capsules, and thought our own 
independent observations may assist here. 

We have used the TetraMic for several years now, and like it. However, yes, we 
have always had to increase pre-amp gain significantly (compared to other 
microphone inputs) to get good input levels and as a result we meter high noise 
levels on each capsule. It doesn't mean we've stopped using the TetraMic, we 
just have to be mindful of this.

Kind regards,

Mark

-Original Message-
From: Sursound  On Behalf Of Jack Reynolds
Sent: Friday, November 3, 2023 7:10 AM
To: Surround Sound discussion group 
Subject: Re: [Sursound] A comparison of fifteen ambisonic microphones

Right. I see.
 
Thanks for the clarification. 

You pointed out various things you thought were errors, which no-one else 
thought were errors, and we didn’t resolve anything at all.

I think it would be the right thing to do to outline your issues here to 
prevent any further doubt being cast on the study. The ‘discussion’ on Facebook 
was a farce and I would rather not repeat that here. 

As I remember you thought it was an unfair comparison because your mics are 
less sensitive, and that meant they would need more input gain and that this 
would unfairly increase the noise floor? 

We added a second recording at an increased gain setting and proved that 
assertion to be incorrect. If a Zoom F8 mic preamp isn’t good enough….?

Your second assertion was that comparing to a KU100 was an unfair comparison 
because a real binaural mic has real ITD. Your solution to this was to use your 
favourite technique of bilateral ambisonics, which would mean finding two of 
every mic, two recorders and twice the number of channels, which seems like a 
waste of time effort to me. 
That point raised some interesting discussion regarding higher order mics 
resolving ITD better than lower order, and various approaches including first 
decoding from ambisonics to SPS/T-Designs before binaural decoding as that 
could potentially render ITD better. 
We tried that and it didn’t sound any better… so we went back to a straight 
ambisonics to binaural decode using Sadie ii KU100 HRTFs. Every mic treated the 
same way, with no exception. 

What else was there?

I seem to remember you didn’t like the Schoeps ORTF3D array being in there for 
comparison. I’m still not sure why. It’s a spaced 3D array, which will 
obviously sound different from the near coincident arrays, but does that matter?

What else was there?

I really do want to resolve this, in public, so we can draw a line under it 
once and for all. 

Please just say what you think should be corrected, and why. 
Also, if you can find a single person that agrees with your assertions I would 
love to hear their opinion. 
From the overly lengthy discussion on Facebook I don’t recall anyone agreeing 
with you. Hence my position that there are in fact no errors in our method. 

The recordings are there for anyone to study. 
If your assertion that there was an error in the process, it casts doubt on our 
study and therefore the usefulness of the files. 

If you are unable to outline what those errors are - I can only assume there 
are in fact no errors, and you are not acting in an honourable manner. 

Apologies to the other Sursounders if this is out of line. Any input would be 
gratefully received.

Thanks

Jack 



Sent from my iPhone

> On 2 Nov 2023, at 19:24, lenmoskow...@optonline.net wrote:
> 
> We discussed the multiple errors in detail in our Facebook discussion.
> 
> That you didn't correct the comparison study, and actually added more 
> incorrect information has made it clear that further discussion won't improve 
> the outcome.
> 
> 
> Len Moskowitz (mosko...@core-sound.com) Core Sound LLC 
> www.core-sound.com Home of OctoMic and TetraMic
> 
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit 
> account or options, view archives and so on.
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Jack Reynolds]

It was on the Spatial Audio in VR/AR/MR group, saved for posterity!

There’s a PDF on the google drive along with files in the original post that 
describes the method.

We recorded a piece of music, played back over a 32 speaker array, on fifteen 
different microphones, at the same gain setting, converted to B-Format with the 
appropriate software and gain matched binaural decodes. That’s it. 

J

Sent from my iPhone

> On 2 Nov 2023, at 19:59, eric benjamin  wrote:
> 
> Where did that facebook discussion appear? I'm interested in the mechanism
> by which microphone comparisons are made.
> 
>> On Thu, Nov 2, 2023 at 12:24 PM  wrote:
>> 
>> We discussed the multiple errors in detail in our Facebook discussion.
>> 
>> That you didn't correct the comparison study, and actually added more
>> incorrect information has made it clear
>> that further discussion won't improve the outcome.
>> 
>> 
>> Len Moskowitz (mosko...@core-sound.com)
>> Core Sound LLC
>> www.core-sound.com
>> Home of OctoMic and TetraMic
>> 
>> ___
>> Sursound mailing list
>> Sursound@music.vt.edu
>> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here,
>> edit account or options, view archives and so on.
>> 
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Jack Reynolds]

Right. I see.
 
Thanks for the clarification. 

You pointed out various things you thought were errors, which no-one else 
thought were errors, and we didn’t resolve anything at all.

I think it would be the right thing to do to outline your issues here to 
prevent any further doubt being cast on the study. The ‘discussion’ on Facebook 
was a farce and I would rather not repeat that here. 

As I remember you thought it was an unfair comparison because your mics are 
less sensitive, and that meant they would need more input gain and that this 
would unfairly increase the noise floor? 

We added a second recording at an increased gain setting and proved that 
assertion to be incorrect. If a Zoom F8 mic preamp isn’t good enough….?

Your second assertion was that comparing to a KU100 was an unfair comparison 
because a real binaural mic has real ITD. Your solution to this was to use your 
favourite technique of bilateral ambisonics, which would mean finding two of 
every mic, two recorders and twice the number of channels, which seems like a 
waste of time effort to me. 
That point raised some interesting discussion regarding higher order mics 
resolving ITD better than lower order, and various approaches including first 
decoding from ambisonics to SPS/T-Designs before binaural decoding as that 
could potentially render ITD better. 
We tried that and it didn’t sound any better… so we went back to a straight 
ambisonics to binaural decode using Sadie ii KU100 HRTFs. Every mic treated the 
same way, with no exception. 

What else was there?

I seem to remember you didn’t like the Schoeps ORTF3D array being in there for 
comparison. I’m still not sure why. It’s a spaced 3D array, which will 
obviously sound different from the near coincident arrays, but does that matter?

What else was there?

I really do want to resolve this, in public, so we can draw a line under it 
once and for all. 

Please just say what you think should be corrected, and why. 
Also, if you can find a single person that agrees with your assertions I would 
love to hear their opinion. 
From the overly lengthy discussion on Facebook I don’t recall anyone agreeing 
with you. Hence my position that there are in fact no errors in our method. 

The recordings are there for anyone to study. 
If your assertion that there was an error in the process, it casts doubt on our 
study and therefore the usefulness of the files. 

If you are unable to outline what those errors are - I can only assume there 
are in fact no errors, and you are not acting in an honourable manner. 

Apologies to the other Sursounders if this is out of line. Any input would be 
gratefully received.

Thanks

Jack 



Sent from my iPhone

> On 2 Nov 2023, at 19:24, lenmoskow...@optonline.net wrote:
> 
> We discussed the multiple errors in detail in our Facebook discussion.
> 
> That you didn't correct the comparison study, and actually added more 
> incorrect information has made it clear
> that further discussion won't improve the outcome.
> 
> 
> Len Moskowitz (mosko...@core-sound.com)
> Core Sound LLC
> www.core-sound.com
> Home of OctoMic and TetraMic
> 
> ___
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[eric benjamin]

Where did that facebook discussion appear? I'm interested in the mechanism
by which microphone comparisons are made.

On Thu, Nov 2, 2023 at 12:24 PM  wrote:

> We discussed the multiple errors in detail in our Facebook discussion.
>
> That you didn't correct the comparison study, and actually added more
> incorrect information has made it clear
> that further discussion won't improve the outcome.
>
>
> Len Moskowitz (mosko...@core-sound.com)
> Core Sound LLC
> www.core-sound.com
> Home of OctoMic and TetraMic
>
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here,
> edit account or options, view archives and so on.
>
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[lenmoskowitz]

We discussed the multiple errors in detail in our Facebook discussion.

That you didn't correct the comparison study, and actually added more 
incorrect information has made it clear

that further discussion won't improve the outcome.


Len Moskowitz (mosko...@core-sound.com)
Core Sound LLC
www.core-sound.com
Home of OctoMic and TetraMic

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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Jack Reynolds]

Hi Len,

Perhaps there were no serious errors after all? 

Your input would be greatly appreciated. 

We put a great deal of effort into this test and your sowing doubt is not 
appreciated. 

Cheers

Jack  



Sent from my iPhone

> On 19 Oct 2023, at 03:01, lenmoskow...@optonline.net wrote:
> 
> For the record, this comparison has serious errors regarding TetraMic and 
> OctoMic.
> 
> Jack, Steve and I have discussed this before. I'm disappointed that the 
> errors have not been corrected.
> 
> 
> Len Moskowitz (mosko...@core-sound.com)
> Core Sound LLC
> www.core-sound.com
> Home of TetraMic and OctoMic
> ___
> Sursound mailing list
> Sursound@music.vt.edu
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> account or options, view archives and so on.
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[jack reynolds]

Dear Len,

I would be grateful if you could detail the errors you mentioned regarding
your microphones in this study.

I look forward to hearing from you.

Thanks in advance.

Jack Reynolds

On Thu, 19 Oct 2023 at 03:01,  wrote:

> For the record, this comparison has serious errors regarding TetraMic
> and OctoMic.
>
> Jack, Steve and I have discussed this before. I'm disappointed that the
> errors have not been corrected.
>
>
> Len Moskowitz (mosko...@core-sound.com)
> Core Sound LLC
> www.core-sound.com
> Home of TetraMic and OctoMic
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here,
> edit account or options, view archives and so on.
>


-- 

07889727365

02036861372

3 Swimmers Lane
Haggerston
London
E2 8FR


www.facebook.com/reynoldsmicrophones

www.sohovr.co.uk
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Jack Reynolds]

Hi Sampo,

I think there’s about 15gb there, which you are welcome to download and host if 
you wish. 

Otherwise The files are publicly available on my google drive. 

I will share the repo with you now.

J

Sent from my iPhone

> On 19 Oct 2023, at 21:33, Sampo Syreeni  wrote:
> 
> On 2023-10-17, jack reynolds wrote:
> 
>> It's quite a large project 
>> 
>>  due to the multichannel files
> 
> Quite the job, so I added the link into the Motherlode as the first outbound 
> link: http://decoy.iki.fi/dsound/ambisonic/motherlode/index.en.html . If 
> you're willing to ship me the actual files, and to have them shown publicly, 
> I *think* I can host a gigabyte or two. Terabytes I can't.
> 
> (I'm woefully late on this project of mine/ours, but at least the base
> material stays online.)
> -- 
> Sampo Syreeni, aka decoy - de...@iki.fi, http://decoy.iki.fi/front
> +358-40-3751464, 025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2
> ___
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Mark Thompson]

Hi Jack, thanks for sharing such a valuable resource for the community. A great 
effort by all of those involved to compile this.

Kind regards,

Mark

-Original Message-
From: Sursound  On Behalf Of jack reynolds
Sent: Tuesday, October 17, 2023 8:25 PM
To: Surround Sound discussion group 
Subject: [Sursound] A comparison of fifteen ambisonic microphones

Hi All,

In April 2022 Axel Drioli, Steven Boardman, John Leonard and I carried out an 
experiment comparing fifteen ambisonic microphones.

We have arranged the recordings into a Reaper project set up to make the 
comparison as easy and fair as possible and we hope this resource is useful to 
the community.

We are all busy people, hence the delay in releasing these files!

I look forward to seeing how these recordings can be used to make further 
comparisons.

It's quite a large project
<https://drive.google.com/drive/folders/1w0UZt9XCPCQOkxoZBRRiVfwnkohUhnd-?usp=share_link>
due to the multichannel files

Cheers

Jack Reynolds

07889727365

02036861372

3 Swimmers Lane
Haggerston
London
E2 8FR


www.reynoldsmicrophones.com
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Sampo Syreeni]

On 2023-10-17, jack reynolds wrote:

It's quite a large project 
 
due to the multichannel files


Quite the job, so I added the link into the Motherlode as the first 
outbound link: 
http://decoy.iki.fi/dsound/ambisonic/motherlode/index.en.html . If 
you're willing to ship me the actual files, and to have them shown 
publicly, I *think* I can host a gigabyte or two. Terabytes I can't.


(I'm woefully late on this project of mine/ours, but at least the base
material stays online.)
--
Sampo Syreeni, aka decoy - de...@iki.fi, http://decoy.iki.fi/front
+358-40-3751464, 025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Panos Kouvelis]

Thanks for the reply Jack, I appreciate it.

Cheers!

Pan

*Pan Athen*
SoundFellas , *MediaFlake Ltd
*
Digital Media Services, Content, and Tools


On Thu, Oct 19, 2023 at 10:16 AM Jack Reynolds 
wrote:

> I would also be interested to know what kind of errors we made, Panos.
>
> I’m sure Mr Moskowitz will enlighten us and we can discuss whether his
> assertions are valid or not.
>
> Cheers
>
> Jack
>
> Sent from my iPhone
>
> > On 19 Oct 2023, at 07:54, Panos Kouvelis  wrote:
> >
> > What kinds of errors should we look for when listening?
> >
> > Thank you for pointing that out :-)
> >
> > *Pan Athen*
> > SoundFellas , *MediaFlake Ltd
> > *
> > Digital Media Services, Content, and Tools
> >
> >
> >> On Thu, Oct 19, 2023 at 5:01 AM  wrote:
> >>
> >> For the record, this comparison has serious errors regarding TetraMic
> >> and OctoMic.
> >>
> >> Jack, Steve and I have discussed this before. I'm disappointed that the
> >> errors have not been corrected.
> >>
> >>
> >> Len Moskowitz (mosko...@core-sound.com)
> >> Core Sound LLC
> >> www.core-sound.com
> >> Home of TetraMic and OctoMic
> >> ___
> >> Sursound mailing list
> >> Sursound@music.vt.edu
> >> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here,
> >> edit account or options, view archives and so on.
> >>
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> >
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> > Sursound@music.vt.edu
> > https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here,
> edit account or options, view archives and so on.
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Jack Reynolds]

I would also be interested to know what kind of errors we made, Panos.

I’m sure Mr Moskowitz will enlighten us and we can discuss whether his 
assertions are valid or not. 

Cheers

Jack

Sent from my iPhone

> On 19 Oct 2023, at 07:54, Panos Kouvelis  wrote:
> 
> What kinds of errors should we look for when listening?
> 
> Thank you for pointing that out :-)
> 
> *Pan Athen*
> SoundFellas , *MediaFlake Ltd
> *
> Digital Media Services, Content, and Tools
> 
> 
>> On Thu, Oct 19, 2023 at 5:01 AM  wrote:
>> 
>> For the record, this comparison has serious errors regarding TetraMic
>> and OctoMic.
>> 
>> Jack, Steve and I have discussed this before. I'm disappointed that the
>> errors have not been corrected.
>> 
>> 
>> Len Moskowitz (mosko...@core-sound.com)
>> Core Sound LLC
>> www.core-sound.com
>> Home of TetraMic and OctoMic
>> ___
>> Sursound mailing list
>> Sursound@music.vt.edu
>> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here,
>> edit account or options, view archives and so on.
>> 
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Panos Kouvelis]

What kinds of errors should we look for when listening?

Thank you for pointing that out :-)

*Pan Athen*
SoundFellas , *MediaFlake Ltd
*
Digital Media Services, Content, and Tools


On Thu, Oct 19, 2023 at 5:01 AM  wrote:

> For the record, this comparison has serious errors regarding TetraMic
> and OctoMic.
>
> Jack, Steve and I have discussed this before. I'm disappointed that the
> errors have not been corrected.
>
>
> Len Moskowitz (mosko...@core-sound.com)
> Core Sound LLC
> www.core-sound.com
> Home of TetraMic and OctoMic
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here,
> edit account or options, view archives and so on.
>
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Jack Reynolds]

Please feel free to outline where you think the errors lie, Len.

We have certainly had discussions but I don’t recall you pointing out errors 
other than your assertion that preamp gain would have a negative effect on the 
noise performance of your microphones, which we proved to be incorrect by 
repeating the measurement and two different gain settings.  You will find both 
recordings in the Reaper project and you will see both have precisely the same 
noise floor in the silence preceding the music. A much higher noise floor than 
any of the other mics tested, I might add, making the effect more obvious in 
comparison to the low level background noise of the studio and the -127 
equivalent input noise of the zoom f8 preamp. 

It’s a pretty straightforward test - 
Record the same input signal, kindly produced by Steven Boardman, at the same 
input gain on multiple microphones. Then loudness match the recordings to play 
back at the same level and listen to the results. 

You also suggested the test would only be fair if we used bilateral ambisonics, 
which is frankly nonsense.

I look forward to your response and the input of other experts to identify 
where we may have made errors.

With kind regards. 

Jack Reynolds


> On 19 Oct 2023, at 03:01, lenmoskow...@optonline.net wrote:
> 
> For the record, this comparison has serious errors regarding TetraMic and 
> OctoMic.
> 
> Jack, Steve and I have discussed this before. I'm disappointed that the 
> errors have not been corrected.
> 
> 
> Len Moskowitz (mosko...@core-sound.com)
> Core Sound LLC
> www.core-sound.com
> Home of TetraMic and OctoMic
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit 
> account or options, view archives and so on.
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[lenmoskowitz]

For the record, this comparison has serious errors regarding TetraMic 
and OctoMic.


Jack, Steve and I have discussed this before. I'm disappointed that the 
errors have not been corrected.



Len Moskowitz (mosko...@core-sound.com)
Core Sound LLC
www.core-sound.com
Home of TetraMic and OctoMic
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Re: [Sursound] A comparison of fifteen ambisonic microphones

[Panos Kouvelis]

Awesome resource! Thanks for sharing :-)

*Pan Athen*
SoundFellas , *MediaFlake Ltd
*
Digital Media Services, Content, and Tools


On Tue, Oct 17, 2023 at 12:25 PM jack reynolds 
wrote:

> Hi All,
>
> In April 2022 Axel Drioli, Steven Boardman, John Leonard and I carried out
> an experiment comparing fifteen ambisonic microphones.
>
> We have arranged the recordings into a Reaper project set up to make the
> comparison as easy and fair as possible and we hope this resource is useful
> to the community.
>
> We are all busy people, hence the delay in releasing these files!
>
> I look forward to seeing how these recordings can be used to make further
> comparisons.
>
> It's quite a large project
> <
> https://drive.google.com/drive/folders/1w0UZt9XCPCQOkxoZBRRiVfwnkohUhnd-?usp=share_link
> >
> due to the multichannel files
>
> Cheers
>
> Jack Reynolds
>
> 07889727365
>
> 02036861372
>
> 3 Swimmers Lane
> Haggerston
> London
> E2 8FR
>
>
> www.reynoldsmicrophones.com
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[Sursound] A comparison of fifteen ambisonic microphones

[jack reynolds]

Hi All,

In April 2022 Axel Drioli, Steven Boardman, John Leonard and I carried out
an experiment comparing fifteen ambisonic microphones.

We have arranged the recordings into a Reaper project set up to make the
comparison as easy and fair as possible and we hope this resource is useful
to the community.

We are all busy people, hence the delay in releasing these files!

I look forward to seeing how these recordings can be used to make further
comparisons.

It's quite a large project

due to the multichannel files

Cheers

Jack Reynolds

07889727365

02036861372

3 Swimmers Lane
Haggerston
London
E2 8FR


www.reynoldsmicrophones.com
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