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How much dynamic range is possible in a simple stereo recording?


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1 hour ago, esldude said:

So which microphone and recording venue gets us to 144 db?  The answer is none of them. So then the question is how close do we get?

 

Tough customer Mr. esldude! :D  I just hope you're not a 'loudness head', lol.    I think mansr is on the right track regarding mics and venues, as he posted a couple hours back.  100dB.  Nothing a DAW with 24bit can't handle.

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4 hours ago, mansr said:

The lowest sound level that can be captured is determined by ambient noise and self-noise of the microphone. The upper limit is likely set by the microphone as going too loud will cause severe distortion and can even damage it. You'll have to check the specs to get accurate numbers, but I doubt you'll find many offering more than 100 dB of usable dynamic range. A good 24-bit ADC will have no trouble recording this.

 

For example Neumann KM183 has A-weighted self-noise of 13 dB and maximum SPL  is 140 dB (0.5% THD). DPA 4006 has A-weighted self-noise of 15 dB and maximum SPL 146 dB. Many of these microphone models have a switchable pad from 10 to 20 dB, so you can roughly shift the dynamic range down by that amount in SPL.

 

But anyway, one way to check is to go through bunch of hires material and see what they have. With my earlier checks and random pick I can say that it is at least more than 16-bit worth.

Signalyst - Developer of HQPlayer

Pulse & Fidelity - Software Defined Amplifiers

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Some classical music clips, with successive versions at -20, -40, -60dB down convinced me that staggering dynamic ranges with recording, and mastering were completely unnecessary - if one is straining to actually hear anything, with volume on max - the -60dB item - then going silly with numbers is pointless ...

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2 hours ago, Miska said:

 

For example Neumann KM183 has A-weighted self-noise of 13 dB and maximum SPL  is 140 dB (0.5% THD). DPA 4006 has A-weighted self-noise of 15 dB and maximum SPL 146 dB. Many of these microphone models have a switchable pad from 10 to 20 dB, so you can roughly shift the dynamic range down by that amount in SPL.

 

But anyway, one way to check is to go through bunch of hires material and see what they have. With my earlier checks and random pick I can say that it is at least more than 16-bit worth.

I couldn't see what in your earlier spectrogram was indicating the difference. Could you explain so I might understand? 

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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2 hours ago, Miska said:

 

Question was about needed digital resolution, so noise-shaping applies in that scope. Noise shaping also affects analog domain if you measure unlimited bandwidth.

 

 

There's a difference on what is detectable level of discrete tone vs  dynamic range. There's no problem detecting single sine at -120 dB in dithered 16-bit data. But if the signal is white noise at -120 dB level, it is undetectable from the noise floor.

 

 

You can only achieve that with 16-bit if you can move enough of the noise out of audible frequency band, which means you have enough sampling rate to move Nyquist far enough above audible frequency band to make space where to "park" the noise moved away from audible band.

 

For example 16-bit data has fixed total noise level, but it's frequency distribution can be anything you decide. However, if your sample rate is 40 kHz, all your usable bandwidth falls within audible range, so you have no place outside of audible band where to move that quantization noise.

 

My understanding is with dither for 44 and 48 khz rates, you shift noise away from where hearing is most sensitive to areas where our thresholds are higher. So the noise is all in the audible band, but still at levels we'll not hear it. While decreasing noise where we might thereby extending the range effectively for human ears.

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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10 hours ago, Miska said:

 

For example Neumann KM183 has A-weighted self-noise of 13 dB and maximum SPL  is 140 dB (0.5% THD). DPA 4006 has A-weighted self-noise of 15 dB and maximum SPL 146 dB. Many of these microphone models have a switchable pad from 10 to 20 dB, so you can roughly shift the dynamic range down by that amount in SPL.

 

But anyway, one way to check is to go through bunch of hires material and see what they have. With my earlier checks and random pick I can say that it is at least more than 16-bit worth.

And what about sensivity or S/N?

For KM183 S/N = 70 dB (/94dBSPL IEC 60268-1).Noise Floor = 24 dBSPL.

Then what about the noise contribution of amplifiers and other analogue equipment before ADC ? Just curious since I have only a rough idea.

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1 minute ago, semente said:

Here's a recording with some quite obvious wide dynamic swings:

 

1.thumb.png.7e4b1394ea033edb783f129b4733154c.png

 

And yet a good CD rip of that will return a reading of DR12 in Foobar 2000 or TT DR meter, the same reading as a track off something by Duran Duran!

 

That is because those applications measure only a portion of the songs' dynamic ranges, not the absolute full range of each.

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31 minutes ago, semente said:

A/DC
A good 24 bit AD like the Apogee 16 X has an S/N of around 120 dB and this means removing 11 dB from the previous weak link, the mic, at 131 dB
You are now recording at 20 bit (120 / 6 = 20)

 

Quite many use Merging Horus or Hapi these days with their ADC cards:

https://www.merging.com/products/interfaces/specifications#a-d8-d-a-d8-d-p-option-card

People with 130V mics certainly use something like Millennia Media mic pre-amps, and some others use for example completely custom built mic pre's for those.

 

I'm personally using RME ADI-2 Pro:

http://rme-audio.de/en/products/adi_2-pro.php#7

Which is so far among the best with unweighted 120 dB and A-weighted 124 dB SNR.

 

Signalyst - Developer of HQPlayer

Pulse & Fidelity - Software Defined Amplifiers

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11 hours ago, esldude said:

My understanding is with dither for 44 and 48 khz rates, you shift noise away from where hearing is most sensitive to areas where our thresholds are higher. So the noise is all in the audible band, but still at levels we'll not hear it. While decreasing noise where we might thereby extending the range effectively for human ears.

 

"for human ears"

 

Suggesting that we extend the range effectively for the authentic reproduction, via domestic or live venue sound system,  of the detonation of a five megaton nuclear warhead at ten miles distance?

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20 minutes ago, The_K-Man said:

 

"for human ears"

 

Suggesting that we extend the range effectively for the authentic reproduction, via domestic or live venue sound system,  of the detonation of a five megaton nuclear warhead at ten miles distance?

 

Have you tried this 16-bit dynamic range audibility test?

 

https://www.audiocheck.net/audiotests_dynamiccheck.php

"Science draws the wave, poetry fills it with water" Teixeira de Pascoaes

 

HQPlayer Desktop / Mac mini → Intona 7054 → RME ADI-2 DAC FS (DSD256)

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There are two entirely different questions which are being conflated here:

 

1) what is the maximum dynamic range that can be recorded

vs

2) what is the maximum dynamic range than can be perceived

 

Those are two significantly different discussions. Folks who are purely interested in perception need to understand the intricacies of recording eg noise shaping — @esldude can say if he intends this thread to discuss perception?

Custom room treatments for headphone users.

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24 minutes ago, jabbr said:

There are two entirely different questions which are being conflated here:

 

1) what is the maximum dynamic range that can be recorded

vs

2) what is the maximum dynamic range than can be perceived

 

Those are two significantly different discussions. Folks who are purely interested in perception need to understand the intricacies of recording eg noise shaping — @esldude can say if he intends this thread to discuss perception?

 

I loathe that word.  'conflate'

 

It's used a lot over on head-fi and Gearslutz, and it's getting tedious.

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2 hours ago, jabbr said:

 

Do you understand? (I don’t post on those sites but perhaps you should consider that your thinking displays a certain pattern)

 

 

Well I don't mince words exactly.  I don't call a duck an 'aquatic bird' - I call a duck a DUCK.   If something sounds overly loud or compressed, or appears so in a DAW interface, it's probably because it is.

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2 hours ago, jabbr said:

There are two entirely different questions which are being conflated here:

 

1) what is the maximum dynamic range that can be recorded

vs

2) what is the maximum dynamic range than can be perceived

 

Those are two significantly different discussions. Folks who are purely interested in perception need to understand the intricacies of recording eg noise shaping — @esldude can say if he intends this thread to discuss perception?

Actually I intended to approach #1 first and then proceed to #2.  

 

#2 however wasn't intended to become "which recording sounds more dynamic to me".  Because it is already known what sounds dynamic vs being of greater dynamic range are two different things altogether. 

 

Now some microphones will record cleanly to 155 or 160 db.  For stereo pair recordings that isn't of much significance.  For up close recording of drum sets or guitar amps it is.   From a natural stereo pair recording saying something had a dynamic range of 135 or 140 db wouldn't mean much as the listener at such an event isn't going to sit happily listening at those levels to achieve that.  Which is why I did mention 120 db SPL. 

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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Excellent topic!

 

I would be interested in comments on the relationship between possible recorded dynamic range as digitally captured and the fact that venue/room is always some number (around 30 it seems).  Folks have mentioned this but I am not sure about the implications.

Hey MQA, if it is not all $voodoo$, show us the math!

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14 hours ago, Arpiben said:

And what about sensivity or S/N?

For KM183 S/N = 70 dB (/94dBSPL IEC 60268-1).Noise Floor = 24 dBSPL.

Then what about the noise contribution of amplifiers and other analogue equipment before ADC ? Just curious since I have only a rough idea.

You may know, but for others that may not. Microphone S/N specs are not what you might think. They use 94 db SPL as a reference (which is one Pascal) and subtract microphone self noise.

 

As Miska said at higher levels the SNR  as you are used to seeing with electronic gear would be mostly down to highest distortion.

 

Most good mic pre amps contribute so little noise it isn't an issue. But if you used gain in the mic pre amp this gain applies to the noise from the mic or the ambient noise. So the example I used earlier is with a Shure KSM 44A.  With my other gear 25 db of mic pre gain will result in 120 db SPL recording at 0 db fs. The 30 db SPL ambient noise will be 90 db below that 120 db SPL peak level. The self noise of the mic will contribute little being 116 db below peak levels.

 

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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