[gregorio]

So you're saying, in our 'Bit-pire State Building', that a super loud compressed song would light up only the TOP-most floors, where as an 1812 or William Tell would reach DOWNWARD, frequently, from the top of our skyscraper analogy?

Correct.

[1] The losses of recording and reproduction require that the signal be reduced in dynamic range at production.
[2] Natural sound in the real world has an agreed dynamic range of 150db.

1. No they don't, if anything the exact opposite is true!

2. Which natural world and who agreed that dynamic range? I ask because it's obviously not this natural world!

G

 

[bigshot]

I think he's defining the natural world as being what ears under the broadest definition can hear.

 

[gregorio]

I think he's defining the natural world as being what ears under the broadest definition can hear.

If we take the noise floor of this natural world to be equivalent to say a quiet sitting room, 150dB dynamic range would peak at 180dB. So: A. As 180dB is usually the figure quoted to cause death, does that really qualify for "what ears can hear"? Permanent hearing damage is usually quoted to occur 100 times lower than 180dB, wouldn't something below that figure (140dB) be more appropriate for what we can hear? B. What on earth in the natural world makes noise/sound at 180dB? The Krakatoa volcanic eruption in 1883 was estimated to be 180dB (from 160 kilometers away), ruptured the ear drums of sailors 64 kilometers away and was clearly heard 5,000 kilometers away. Not many symphonies include super-volcano eruptions though!

G

 

[drtechno]

This is just one example. This also includes the theoredical limit decibels at 1 atmosphere, which there isn't anything that has been measured to be that. But I imagine the shock-wave of an atomic bomb is between 150-194db.

 

[gregorio]

This is just one example. This also includes the theoredical limit decibels at 1 atmosphere, which there isn't anything that has been measured to be that. But I imagine the shock-wave of an atomic bomb is between 150-194db.

So apart from a nuclear bomb and a volcanic eruption there is nothing in the world which requires a 150dB dynamic range and I'm not sure a nuclear bomb qualifies as "natural world". Regardless, who has a sound system capable of 180dBSPL and if someone did, why would they actually play it that loud (unless they were deliberately committing suicide)?

G

 

[TheSonicTruth]

Correct.


1. No they don't, if anything the exact opposite is true!

2. Which natural world and who agreed that dynamic range? I ask because it's obviously not this natural world!

G

Re: Correct: So from the top down, which would reach down to lower bit(floors), louder or softer moments?

 

[drtechno]

This is just spl though. To ask a loudness question in more musical terms: What is the distance between mezzo piano and fortissimo needed to be for it to translate in and out of digital correctly?

 

[gregorio]

Re: Correct: So from the top down, which would reach down to lower bit(floors), louder or softer moments?

Softer moments would be in the lower bits, bit 16 for the quietest.

This is just spl though. To ask a loudness question in more musical terms: What is the distance between mezzo piano and fortissimo needed to be for it to translate in and out of digital correctly?

Mezzo piano and fortissimo on what, a guitar or a symphony orchestra? For a symphony orchestra, probably around 40-45dB or so.

G

 

[drtechno]

about 40db in contrast in real life, but doesn't this distance change when it is recorded?

This is just a spl meter chart of what is measured with people playing:

or even translating linerarlly in and out of the digital domain:

btw the console clipping point is just a threshold setting on professional recording consoles (+32 nominally is usually the threshold of clipping). Live consoles are +18db (usually)

 

[bigshot]

If we take the noise floor of this natural world to be equivalent to say a quiet sitting room, 150dB dynamic range would peak at 180dB.

Yes, but ears hear from theoretical zero (in a cave the only noise floor would be the blood pumping through your eardrums) up to the point where you go deaf. That would be about 150dB. I agree that it isn't a very useful figure for the real world. I'm just so used to people thinking in terms of absolutes and extremes around here.

about 40db in contrast in real life, but doesn't this distance change when it is recorded?

Recordings are generally mixed to be comfortable to listen to. An orchestra may put out peaks of 100dB to 110dB if you are standing right in front of the brass section, but recordings are made from the perspective of a person sitting in the audience. Distance reduces dynamic range.

 

[gregorio]

about 40db in contrast in real life, but doesn't this distance change when it is recorded?

No, why would it? 70dB total dynamic range is about right for a large symphony orchestra. It would be recorded with that same dynamic range and then mixed and mastered either at that dynamic range or somewhat reduced to fall within the range of consumer listening comfort.

G

 

[gregorio]

Yes, but ears hear from theoretical zero (in a cave the only noise floor would be the blood pumping through your eardrums) up to the point where you go deaf. That would be about 150dB.

If you're In a cave deep enough underground to achieve 0dB, what exists that deep in a cave in the natural world that makes a noise at 150dB?

G

 

[bfreedma]

If you're In a cave deep enough underground to achieve 0dB, what exists that deep in a cave in the natural world that makes a noise at 150dB?

G

I’m not sure 0dB is possible, even in fossil caves, due to geological activity. A pressurized steam vent release might reach 150dB, though it would take a near perfect scenario to get that loud.

We may be learning more soon: http://thesenseofsilencefoundation....nd-of-caves-listening-to-the-sound-of-silence

 

[TheSonicTruth]

Softer moments would be in the lower bits, bit 16 for the quietest.



Mezzo piano and fortissimo on what, a guitar or a symphony orchestra? For a symphony orchestra, probably around 40-45dB or so.

G

Softer moments would be in the lower bits, bit 16 for the quietest.

Could you clarify that for me please? Visualize it if necessary - I learn better seeing than by reading.

 

[drtechno]

maybe an anechoic chamber, but I think the instrumentation itself isn't sensitive enough to measure that low of a db