Topic: 24-bit word length and setting levels (yes, again)

[BWolf]

108 dB / 65,536 bits = 0.0016479 dB/bit

108 dB / 262,144 bits = 0.0004119 dB/bit

120 dB / 262,144 bits = 0.0004577 dB/bit
 

Dude...  There are 6.0205999132796239042747778944899... dB/bit, no matter how many bits you have or what dynamic range you have available.

care to explain yourself...

[KLowe]

http://www.korg.com/mr/Future_Proof_Recording_Explained.pdf   This write up has some great explainations of bits and sampling rate.  Explains why 24 bit loses it's purpose at lower sample rates.

Great discussion.  I have learned a ton from this thread.

[SparkE!]

108 dB / 65,536 bits = 0.0016479 dB/bit

108 dB / 262,144 bits = 0.0004119 dB/bit

120 dB / 262,144 bits = 0.0004577 dB/bit
 

Dude...  There are 6.0205999132796239042747778944899... dB/bit, no matter how many bits you have or what dynamic range you have available.

care to explain yourself...

The dynamic range of a bit is 20 log (2).  Period.

I think you are confusing the number of possible levels with the number of bits.

[BWolf]

108 dB / 65,536 bits = 0.0016479 dB/bit

108 dB / 262,144 bits = 0.0004119 dB/bit

120 dB / 262,144 bits = 0.0004577 dB/bit
 

Dude...  There are 6.0205999132796239042747778944899... dB/bit, no matter how many bits you have or what dynamic range you have available.

care to explain yourself...

The dynamic range of a bit is 20 log (2).  Period.

I think you are confusing the number of possible levels with the number of bits.

Nope.  You are actually confusing two different things.  1 bit is approx 6 dB of dynamic range when talking about how many bits you are going to use.  So in a 16 bit environment, we have 96 dB of dynamic range, and in an 24 bit environment there is 144 dB of dynamic range.

This is completely different then the amount of decibels a single bit represents when you look at the actual data saved.  When 0000 0000 0000 0000 changes to 0000 0000 0000 0001, the audible different will be 0.0016479 dB. 

In my example, the dB/bit was in relation to the amount that the actual bit represents when converting bits back to the analog realm.  When talking about 1 bit = 6 dB, you are talking about the number of bits that are going to be used.  Two completely different topics.

[SparkE!]

When 0000 0000 0000 0000 changes to 0000 0000 0000 0001, the audible different will be 0.0016479 dB. 

Dude, there are not 65,536 bits in a 16 bit sample.  There are 16 bits in a 16 bit sample.  There are 65,536 possible values that can be represented by a 16 bit number.  You are confusing the possible number of sample values with bits.

And what do you mean by "When 0000 0000 0000 0000 changes to 0000 0000 0000 0001"?  And what does that have to do with dB's?  Do you know the definition of dB?  FWIW, it is 20 times the log of the ratio between two numbers.  What ratio are you using?  If you were taking the ratio of 0000 0000 0000 0000 and 0000 0000 0000 0001, that doesn't make sense.  There is no such thing as a log of 0 and if you invert the ratio, you'd be dividing by 0 (also no such thing).

I'm not trying to piss you off or anything, but I'm thinking you don't really understand the concept of a logarithmic scale, what is meant by dB and how those two concepts are related.

[BWolf]

When 0000 0000 0000 0000 changes to 0000 0000 0000 0001, the audible different will be 0.0016479 dB. 

Dude, there are not 65,536 bits in a 16 bit sample.  There are 16 bits in a 16 bit sample.  There are 65,536 possible values that can be represented by a 16 bit number.  You are confusing the possible number of sample values with bits.

And what do you mean by "When 0000 0000 0000 0000 changes to 0000 0000 0000 0001"?  And what does that have to do with dB's?  Do you know the definition of dB?  FWIW, it is 20 times the log of the ratio between two numbers.  What ratio are you using?  If you were taking the ratio of 0000 0000 0000 0000 and 0000 0000 0000 0001, that doesn't make sense.  There is no such thing as a log of 0 and if you invert the ratio, you'd be dividing by 0 (also no such thing).

I'm not trying to piss you off or anything, but I'm thinking you don't really understand the concept of a logarithmic scale, what is meant by dB and how those two concepts are related.

No, I completely understand.  I actually have an electrical engineering degree.  I think we are arguing semantics.  Yeah, I meant values (65536 unique values).  And I understand what a dB is.  And I understand logarithmic scale and how it works.  I was trying to explain it to people who don't necessarily understand all the technical, deep details. 

I would like to have this conversation in full detail though.  Its an important conversation for people to understand and there aren't that many people who will take time to explain it all.  Like I said, I didn't think this was the place to get into all that. 

[SparkE!]

No, I completely understand.  I actually have an electrical engineering degree.  I think we are arguing semantics.  Yeah, I meant values (65536 unique values).  And I understand what a dB is.  And I understand logarithmic scale and how it works.  I was trying to explain it to people who don't necessarily understand all the technical, deep details. 

OK, as one electrical engineer to another, explain to me why you think that dividing the dynamic range by the number of possible values that a single value can take has any sort of meaning?  What is represented by that number?  Explain its relevance to this discussion.  The dynamic range is expressed as a logarithmic number and the number of possible values that a given sample can take is a linear number.  Not only that, but the dynamic range is just 20 log (the number of possible values a sample can take).  Both of the numbers you are dividing represent exactly the same thing, but they are represented on two different scales, one of which is logarithmic and the other of which is linear.  This is like dividing Decibels by Pascals.

[pool]

 Seems like the dithering process is not doing what it supposed to be doing or am I missing something here?  I thought that these programs mazimizes the bit usage (thus the special patented algorithms).  If there something better to use as a plugin to Wavelab, I would like to know about it.  Are people are using WAVES IDR?
[/quote]

I use iZotope Ozone 3 plugin. Seemes to be quite high quality.

[BWolf]

No, I completely understand.  I actually have an electrical engineering degree.  I think we are arguing semantics.  Yeah, I meant values (65536 unique values).  And I understand what a dB is.  And I understand logarithmic scale and how it works.  I was trying to explain it to people who don't necessarily understand all the technical, deep details. 

OK, as one electrical engineer to another, explain to me why you think that dividing the dynamic range by the number of possible values that a single value can take has any sort of meaning?  What is represented by that number?  Explain its relevance to this discussion.  The dynamic range is expressed as a logarithmic number and the number of possible values that a given sample can take is a linear number.  Not only that, but the dynamic range is just 20 log (the number of possible values a sample can take).  Both of the numbers you are dividing represent exactly the same thing, but they are represented on two different scales, one of which is logarithmic and the other of which is linear.  This is like dividing Decibels by Pascals.

right.  thats my fault.  i should have moved into the frequency domain and showed the levels based on the amount of frequencies that are being covered (20 Hz - 20 kHz).  it was late, i just got back from my buckeyes getting thier ass whooped in arizona, and i wasn't thinking straight.  sorry for the confusion anyone. 

[SparkE!]

right.  thats my fault.  i should have moved into the frequency domain and showed the levels based on the amount of frequencies that are being covered (20 Hz - 20 kHz).  it was late, i just got back from my buckeyes getting thier ass whooped in arizona, and i wasn't thinking straight.  sorry for the confusion anyone. 

Well, I'm sorry for hijacking the thread too.  My BS detector went off and I couldn't get the dang thing turned off quickly enough.  On a normal day, I would have just let it go.  Now back to your regularly scheduled programming...

[Jhurlbs81]

there's a difference between BS'ing and making an error.  I don't think Brad was BS'ing us.

Jesse

[Nick's Picks]

thats more my depart.