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Recommend sofware with high-precision FFT analysis with resolution to -384dB?

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Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Fri Jul 19, 2019 8:40 pm
by Uncle Freddie
Hi,

Can anyone recommend Mac and/or PC audio analysis software packages that -- and here's the tricky part -- offer high-precision FFT analysis with resolution all the way down to -384dB? That would be 64 bits of resolution.

Thanks,
Fred

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Fri Jul 19, 2019 8:55 pm
by Folderol
Good Lord!
What on earth for? :o

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Fri Jul 19, 2019 8:58 pm
by Hugh Robjohns
:D that was going to be my question, too!

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Sat Jul 20, 2019 6:32 am
by Uncle Freddie
:) :)

I'm looking for this depth of resolution for test and measurement of truncation noise and other distortions.

In macOS, I have used Aurchitect's Spectre software for this, eventually switching to their Aura package. Both are considerably buggy. On top of that, in mid-May the company went out of business over ownership lawsuits. They even wiped their website (http://aurchitect.com) completely off the air.

I recently began using SPL Hawkeye, but it only goes down to -220dB (I have filed an enhancement request to increase that to -384dB)

Surely there must be software out there, Mac or PC, perhaps aimed at the test and measurement audience, that can do this?

Thanks,
Fred

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Sat Jul 20, 2019 8:52 am
by Martin Walker
I must admit I'm still a bit in the dark - highly regarded plug-in developers have stated that in most cases for audio work you can declare anything further down than -125dB below the signal as inaudible :?


Martin

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Sat Jul 20, 2019 8:57 am
by ef37a
Martin Walker wrote:I must admit I'm still a bit in the dark - highly regarded plug-in developers have stated that in most cases for audio work you can declare anything further down than -125dB below the signal as inaudible :?


Martin

Quite. Nothing is that quiet except perhaps liquid Helium?

Dave.

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Sat Jul 20, 2019 8:59 am
by Sam Spoons
Is there a theoretical measurement for 'absolute silence'? :D

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Sat Jul 20, 2019 9:07 am
by Martin Walker
I'm beginning to suspect that Uncle Freddie may be exploring mathematical concepts/algorithms, rather than real-world audio.

However, I'd still be surprised if any signal that low would be worth exploring, apart from in a cutting edge lab environment.

Fascinated to hear more though!


Martin

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Sat Jul 20, 2019 9:30 am
by ef37a
Sam Spoons wrote:Is there a theoretical measurement for 'absolute silence'? :D

Well, as per my "He" at absolute zero, by definition energy is zero* so that has to be zero noise?

*I understand there can still be electron spin but can you "hear" electrons? BTW "I understand" is just a turn of phrase. I don't!

Dave.

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Sat Jul 20, 2019 10:24 am
by Logarhythm
ef37a wrote:
Sam Spoons wrote:Is there a theoretical measurement for 'absolute silence'? :D

Well, as per my "He" at absolute zero, by definition energy is zero* so that has to be zero noise?

*I understand there can still be electron spin but can you "hear" electrons? BTW "I understand" is just a turn of phrase. I don't!

Dave.
There is no absolute zero, Dave ;)
Well there is in terms of 0 Kelvin, but quantum mech prohibits this being a truly zero energy state and it's perhaps better viewed as the lowest energy state - thus there will still be "noise" of sorts, and indeed noise is perhaps an appropriate adjective for e.g. quantum vacuum fluctuations.

And I'm also really curious to know what Uncle Freddie is up to!

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Sat Jul 20, 2019 10:25 am
by blinddrew
It's amazing the things you learn on here.

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Sat Jul 20, 2019 11:02 am
by ConcertinaChap
Logarhythm wrote:There is no absolute zero, Dave ;)
Well there is in terms of 0 Kelvin, but quantum mech prohibits this being a truly zero energy state and it's perhaps better viewed as the lowest energy state

That's true. Interestingly from a classical perspective as well you can't reach absolute zero because it's one of these boundary conditions, like the speed of light, that require greater and greater amounts of energy the closer you approach them and would require infinite energy to actually achieve.

Logarhythm wrote:And I'm also really curious to know what Uncle Freddie is up to!

:thumbup:

CC

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Sat Jul 20, 2019 11:40 am
by Wonks
Can't be for audio, as the electronic noise of the input system will create a noise floor way above the lowest resolution of the analyser. That limits the resolution of a standard 24-bit A/D audio converter to maybe 21 bits, 22 at best. So even if you used a 64-bit A/D converter set up with it's upper limit at around 150dB, I'd guess you'd be wasting at least 30 of those bits as they'd be below the electronics noise floor.

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Sat Jul 20, 2019 2:30 pm
by Uncle Freddie
I would be delighted to tell you all what I am up to, but I cannot at the moment. ;) Soon, though.

In case I was not clear earlier: Aurchitect's Aura indeed has FFT resolution down to -384dBFS. What I am asking for is not unheard of. :D

I still use it, or rather I try desperately to use it, because I am fed up with its bugs. Which by the way will never be fixed, now that the company has gone belly-up.

Aura is Mac software, but I am entirely open to a Windows utility for this.

Thanks,
Fred

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Sat Jul 20, 2019 2:55 pm
by James Perrett
For serious analysis work most people would be thinking of Matlab or the free alternatives like Scilab or Gnu Octave.

Re: Recommend sofware with high-precision FFT analysis with resolution to -384dB?

PostPosted: Thu Jul 25, 2019 2:10 am
by DC-Choppah
Mathematica supports data types with arbitrarily large precision. You can do an FFT on data with as high a precision as you want.

X:=N[{0,0,0,1,1,2,1,1,0,0},100]

Defines a waveform stored numerically with a data type having 100 significant digits.

Any process you apply will be done with that precision such as an FFT.

Fourier[X]