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audiojerry

Is bit depth about dynamic range or data?

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I thought after all this time I was correctly explaining bit depth and sample rates to my non-audiophile friends, but now I"m not so sure. I thought that bit depth or bit size determines how much information can be captured in a single sample taken from an analog signal. So if, for example, you are recording a symphony orchestra, there are lots of instruments creating a lot of complex tonal information and sound  levels. This creates a complex analog waveform, and when you take a sample of this waveform, you are going to digitize it and store it in a file. This single sample of the waveform would obviously contain a lot of information about what was happening in this symphony orchestra in that instant of time. The larger the bit depth, the more information you can capture, and you have a better quality file to produce a better quality recording.

 

But now I'm hearing that bit depth is all about dynamic range. That seems too simplistic to me.  

Any experts out there who can set me straight?

 

 

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17 minutes ago, fas42 said:

 

Where digital "gets it wrong" for many people in the real world of playback, is that critical information that is encoded at relatively quiet levels compared to the maximum signals that are occurring at the same time, is too distorted by imperfections in the playback chain to be easily discerned by the listening mind - people hear this all the time in sub-par systems; a track which is a complex mix of sounds is played, and it "sounds a mess!" ... the dynamic range is there, as a technical, measurable characteristic, but distortion of low level information is too great - and subjectively "you can't hear what's going on" ...

 

I recently posted a clip of a track from a Ry Cooder album, and the response was that it "just collapses into a bowl of mush" - this is a classic symptom of inadequate effective resolution of the playback chain; subjectively, the "dynamic range" is not good enough ... and this has absolutely nothing to do with the encoding using only 16bits.

 

 

While I don't have too much of a problem with the first paragraph, if the posted clip was from YouTube, even most mediocre systems should have no problems playing virtually all YouTube Audio without any real problem.

 

I also agree with this comment from Mansr

Quote

Even with flat 16-bit TPDF dither, a 1 kHz tone at -100 dBFS is audible over headphones, even though the dither noise is subjectively louder.

 


How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

 

PROFILE UPDATED 26-12-2019

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7 minutes ago, sandyk said:

 

While I don't have too much of a problem with the first paragraph, if the posted clip was from YouTube, even most mediocre systems should have no problems playing virtually all YouTube Audio without any real problem.

 

 

Again, the posting of a YouTube clip is there as an easy way to reference the style of the music, etc - it wouldn't make sense to prove you how good my system was, by ringing you up on my old fashioned corded phone, and holding up the handset so that you could listen ... 🙂.

 

Played that CD of Ry Cooder a couple of visits ago to the local audio friend ... ummm, was not good - not a mush, but very dodgy on the ears, 😉.


Frank

 

http://artofaudioconjuring.blogspot.com/

 

 

Ahhh, Mankind ... Porsche intellect, Trabant emotions ...

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22 minutes ago, fas42 said:

it wouldn't make sense to prove you how good my system was, by ringing you up on my old fashioned corded phone, and holding up the handset so that you could listen ... 🙂.

 

The old fashioned analogue corded phone was vastly superior in the area of clarity, in the  latter days of the Analogue networks (at least in Australia) , to anything currently available via Digital networks with their typical 300-3,000HZ frequency response  , and did quite a reasonable job with reproducing music too, after the replacement of the old carbon microphones with electret type microphones . Rocking Armature type receivers even did a reasonable job reproducing the sound of Air Conditioning given the use of later opamps than the 709 to drive them.


How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

 

PROFILE UPDATED 26-12-2019

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44 minutes ago, bluesman said:

The Bell system “speech band” was 300-3400 Hz through decades of dial phone use.  Bell Labs did a lot of research to determine everything from the optimal frequency response of their phones to the size of the holes in the dial and buttons on touch tone phones. The equipment was very high quality until the demise of Bell - and it was tough as nails.  I suspect that those black dial phones were bulletproof!

 

I blew a 6L6 in my guitar amplifier on a gig in the summer of 1968. It was almost midnight, and I had no spare.....but we had another 2 hours to play. So I called the phone company’s repair service from the club, explained my predicament, and asked if they had any tubes I could buy. The guy who answered asked where I was and said he’d get back to me.  About ten minutes later, a Bell System truck pulled up and the driver brought two 6L6s to the bandstand, telling me I should replace both for best sound. I asked what I owed him, and he asked for my home phone number - he told me it was “repair service” because I was a customer!

Yes, that's what I call service. :D

The bulk of our Analogue network ,at least in Sydney was determined by the distance and the amount of attenuation. and used balanced transmission feeds .

 Outlying and new areas had to use PCM systems of course, the passband of which varied a little between the system manufacturers. . To maintain a high S/N, the earths of the various exchanges needed to be very low, or there could be a small amount of hum. The earth systems occasionally needed upgrading.

We had a problem with the remaining amount of Strowger (USA) equipment at Chatswood in Sydney, as the Ring Tone was derived via  capacitors from the actual LF ring, and didn't get through the Carrier Systems to some other states.

 It would appear to be a No Progress call until somebody suddenly answered. My O.I.C asked me for assistance , so  I used a DIY 52V transistor amplifier from the new ARE11 Processor controlled exchange to modulate the LF ring with the 400HZ ring tone which was used to supply the remaining Strowger gear until it was replaced. This also benefitted a couple of large PABXs in the area which were fed ring from the exchange via dedicated pairs.


How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

 

PROFILE UPDATED 26-12-2019

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Bit depth is about the signal to noise ratio. If you reduce the depth, you get a higher level of random noise - tape hiss is the obvious analogue variant. A decent digital encoding can capture that tape hiss with ease, so "everything that matters" is being transferred

 

This all assumes that the person who might be playing around with bit depth, while recording and/or mastering, knows how to apply the correct dither, at the correct point of operations ... get it wrong, and you can hear the mistake.

 

Human hearing can compensate for random loss of data, or excess noise, remarkably well - good handling of digital data can rely on that ability, to make even poor bit depth "sound OK".

 

Dynamic range is purely about mastering decisions - nothing to do with bit depth.


Frank

 

http://artofaudioconjuring.blogspot.com/

 

 

Ahhh, Mankind ... Porsche intellect, Trabant emotions ...

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2 minutes ago, mansr said:

Signal to noise ratio and dynamic range are the same thing.

 

Yes, if one is talking about it as a purely technical level concept - but dynamic range is thrown around these days as having subjective connotations - as in, "orchestral performances can't be captured by 16 bits, the sound is, too big!" ... I was referring to this subjective take on the matter.


Frank

 

http://artofaudioconjuring.blogspot.com/

 

 

Ahhh, Mankind ... Porsche intellect, Trabant emotions ...

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