[RRod]

With the Ponostore (poh-nah-stoh-ree?) looming as a source of HD material, I've been doing as much fiddling with filters and test files as I know how to verify what I can hear. At this point, I think I've verified that nothing on this green Earth will let me benefit from >16kHz frequencies. With that settled, I moved on to the 16- vs 24-bit question.
 
I made a little test file, which is a full-bore triangle wave at 100Hz followed by as quiet a square-wave as I could get at 3200Hz with my hacked-together dithering algorithm.  Here it is:
https://drive.google.com/file/d/0BwmVtb5IwniEY1VZQWxIbDdaaVk/view?usp=sharing
 
What are the caveats of such a test file? That is, what real-life situations would take away from the dynamic range of this test? What could add to it? If this is a dumb example I'd like to know.  Otherwise, ostensibly, it seems that the dynamic range of 16 bits (here maybe even just 14-15 bits) is pretty darn huge, making me question what another byte could get me as an end-user (and verify what theory would say anyway).  

 

[Steve Eddy]

What's important to remember is that the instantaneous dynamic range of our hearing is only about 60-70dB.

You often hear people say that the dynamic range of our hearing is about 120dB. But that is very misleading. Yes, if you sit in an anechoic chamber and let your ears acclimate for about 20 minutes, you can ultimately hear the noise of the air molecules beating on your eardrums (about 0dB SPL). From there you can hear up to the threshold of pain at between 120-140dB SPL. But you can't hear both at the same time.

Hell, the ambient noise in a "quiet" room is about 40dB SPL.

So you're just never going to be able to hear the difference in dynamic range between a 16 bit recording and a 24 bit recording. The dynamic range of a 16 bit recording already exceeds the instantaneous dynamic range of our hearing by over 20dB.

se

 

[Strangelove424]

This sounds like a dangerous test to me. As far as I can tell, the benefit of higher bits is higher dynamic range, and this test is trying to see how quiet you can play one tone vs how loud you can play another.... but what happens when you go from 40db just above the ambient floor to 120db+? Even if your amp was capable of reproducing those dynamic range levels possible with 24 bits (which is rare for headphone amps and almost unheard of for speaker amps)I don't see any practical benefit to having a DR that big. It's only begging for hearing troubles. I'm going to DL the file, but I plan to listen to it on a pair of decidedly low-fi equipment with the sound turned way down at first... that's how worried I am about the possible dangers of this test. 
 
Edit: Steve's comments are bang on... your bodies physical defenses (built-in loudness normalization) will kick in way before you can even perceive that DR. And I forgot to say, there is also no natural source of music with a DR that high anyway. Anything over 70 or 80db of range is totally artificial for any acoustic source, and even 80db is pushing it for something like an artificially amplified rock concert. 

 

[RRod]

What's important to remember is that the instantaneous dynamic range of our hearing is only about 60-70dB.

You often hear people say that the dynamic range of our hearing is about 120dB. But that is very misleading. Yes, if you sit in an anechoic chamber and let your ears acclimate for about 20 minutes, you can ultimately hear the noise of the air molecules beating on your eardrums (about 0dB SPL). From there you can hear up to the threshold of pain at between 120-140dB SPL. But you can't hear both at the same time.

Hell, the ambient noise in a "quiet" room is about 40dB SPL.

So you're just never going to be able to hear the difference in dynamic range between a 16 bit recording and a 24 bit recording. The dynamic range of a 16 bit recording already exceeds the instantaneous dynamic range of our hearing by over 20dB.

se

 
Thanks for the reply! So what would that mean in terms of physical effect of a sudden jump from, say, -80dB up to 0?  Does the 0 sound softer than it would otherwise until you acclimate to it? Listening to the two waveforms separately with a short rest requires a good turn of the pot to make the sound either detectable or non-ear-splitting, which syncs up with what you say as the dB jump is in the 80 range.
 
As a side question, is it as simple as "room noise + 96dB" as the range for 16bit in a given recording environment?

 

[RRod]

  This sounds like a dangerous test to me. As far as I can tell, the benefit of higher bits is higher dynamic range, and this test is trying to see how quiet you can play one tone vs how loud you can play another.... but what happens when you go from 40db just above the ambient floor to 120db+? Even if your amp was capable of reproducing those dynamic range levels possible with 24 bits (which is rare for headphone amps and almost unheard of for speaker amps)I don't see any practical benefit to having a DR that big. It's only begging for hearing troubles. I'm going to DL the file, but I plan to listen to it on a pair of decidedly low-fi equipment with the sound turned way down at first... that's how worried I am about the possible dangers of this test. 
 
Edit: Steve's comments are bang on... your bodies physical defenses (built-in loudness normalization) will kick in way before you can even perceive that DR. And I forgot to say, there is also no natural source of music with a DR that high anyway. Anything over 70 or 80db of range is totally artificial for any acoustic source, and even 80db is pushing it for something like an artificially amplified rock concert. 

 
That's why I made sure to put the loud part first and turn off track replay

 

[Steve Eddy]

Thanks for the reply! So what would that mean in terms of physical effect of a sudden jump from, say, -80dB up to 0?  Does the 0 sound softer than it would otherwise until you acclimate to it? Listening to the two waveforms separately with a short rest requires a good turn of the pot to make the sound either detectable or non-ear-splitting, which syncs up with what you say as the dB jump is in the 80 range.

Yes, basically if you're listening to a low level signal for a period of time, jacking that signal up suddenly will be a bit of a shock until your ears acclimate. And going the other way around, you may not even be able to hear the low level signal immediately.

But the salient point is that as dynamic range of the signal goes over about 70dB, you're just moving into more and more lily gilding. Now, during the recording process you want a lot of dynamic range because noise is cumulative. But once the recording has been made, it makes little sense to render it at 24 bits for the sake of dynamic range.

As a side question, is it as simple as "room noise + 96dB" as the range for 16bit in a given recording environment?

More like 96dB - ambient noise. The ambient noise takes away from the dynamic range of the medium.

se

 

[RRod]

More like 96dB - ambient noise. The ambient noise takes away from the dynamic range of the medium.

se

 
Hmm, ok.  So why do people talk about going 96dB above the noise floor?  I figured that would mean in a, say, a 20dB recording room you could capture 20 - 116dB, but from what you're saying you would only get 20-96dB.  Or am I using the wrong terminology somewhere?

 

[Steve Eddy]

Hmm, ok.  So why do people talk about going 96dB above the noise floor?  I figured that would mean in a, say, a 20dB recording room you could capture 20 - 116dB, but from what you're saying you would only get 20-96dB.  Or am I using the wrong terminology somewhere?

Well the 96dB figure is for "digital" itself. With digital you effectively get 6dB of dynamic range for each bit. 16 x 6 = 96. 24 x 6 = 144. Of course there are limitations on the practical implementation, i.e. an actual DAC chip. But that's where the 96dB figure comes from.

That has no particular bearing on the actual recording though. If you're using noisy old analog equipment in the studio, or recording originally to analog tape, the dynamic range of the recording itself may not be anywhere near 96dB. Just that the 96dB of dynamic range won't get in the way of all that other noise.

se

 

[RRod]

Well the 96dB figure is for "digital" itself. With digital you effectively get 6dB of dynamic range for each bit. 16 x 6 = 96. 24 x 6 = 144. Of course there are limitations on the practical implementation, i.e. an actual DAC chip. But that's where the 96dB figure comes from.

That has no particular bearing on the actual recording though. If you're using noisy old analog equipment in the studio, or recording originally to analog tape, the dynamic range of the recording itself may not be anywhere near 96dB. Just that the 96dB of dynamic range won't get in the way of all that other noise.

se

 
Ah ok, thanks for clarifying. I do find it… interesting when people laud the abilities of 24-bit then go on to wonder how much better their recordings made in 1945 will sound.

 

[castleofargh]

I got 1liter of water inside a 1.5liter bottle. man I'm sure 1.5liter of water would taste so good. if only I could put it into my 1.5L bottle. well if I put that water inside a 2liter bottle, now the water is gonna taste soooo good.
I know it because water experts can always tell the water inside the 2liter bottle tastes better, at least they can as long as they see the bottles before drinking. but that's a technicality, they are experts so you can trust them and go buy 2L bottles full of better 1L water.
 
and it all started when a clever dude used 1L of beer inside the 2L bottle, people started thinking that all 2L bottles would taste like beer. and never got around thinking they could put beer inside the 1.5liter bottles and have the exact same experience or even put 1.5L inside it.
 
 
pavlov: 1
additions and subtractions: 0

 

[Strangelove424]

After listening to the test track, I found I couldn't hear the quiet parts if I adjusted the loud parts to comfortable levels. To hear the 3200hz part, the 100hz signal became unbearable and even began clipping. If the loud frequency were in the mids or highs, it would have been torture. Although I used measly equipment for this, to me the results speak for themselves. A dynamic range mastered to be this wide would be horrible for music or even movies. I'd always be running to the volume knob.   

 

[RRod]

  I got 1liter of water inside a 1.5liter bottle. man I'm sure 1.5liter of water would taste so good. if only I could put it into my 1.5L bottle. well if I put that water inside a 2liter bottle, now the water is gonna taste soooo good.
I know it because water experts can always tell the water inside the 2liter bottle tastes better, at least they can as long as they see the bottles before drinking. but that's a technicality, they are experts so you can trust them and go buy 2L bottles full of better 1L water.
 
and it all started when a clever dude used 1L of beer inside the 2L bottle, people started thinking that all 2L bottles would taste like beer. and never got around thinking they could put beer inside the 1.5liter bottles and have the exact same experience or even put 1.5L inside it.
 
 
pavlov: 1
additions and subtractions: 0

 
I'm Amurkan, so I'm not sure what an "L" of beer is, but are you suggesting a limit on beer?…
 

  After listening to the test track, I found I couldn't hear the quiet parts if I adjusted the loud parts to comfortable levels. To hear the 3200hz part, the 100hz signal became unbearable and even began clipping. If the loud frequency were in the mids or highs, it would have been torture. Although I used measly equipment for this, to me the results speak for themselves. A dynamic range mastered to be this wide would be horrible for music or even movies. I'd always be running to the volume knob.   

 
That was my experience too: 100Hz = 7pm, 3200Hz = 5pm (almost needed to go to hi gain on my v200 to hear it).  I can't see even movies needing this much range.

 

[castleofargh]

  I'm Amurkan, so I'm not sure what an "L" of beer is, but are you suggesting a limit on beer?…

 
 
 
obey hypnotoad, abandon now your witchcraft and convert to the rational power of the international system!!!!!!!! (I say that but we use inches all the time for pictures and screen resolutions ^_^)