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What is 24/192? - Page 4

post #46 of 60
Quote:
Originally Posted by vytman View Post

I'm not sure I get it, so there aren't practical advantages choosing 24 bit over 16 bit? I feel I'm missing something lol.

 

Yes, for storage of (especially dynamically compressed) music, 16 bit is generally good enough, and the quantization noise cannot be heard at reasonable listening levels in a typical environment. Although 24 bit support does have the advantage of making it possible to process the signal (e.g. digital volume control, equalization, etc.) without further loss of information.

 


Edited by stv014 - 1/29/12 at 3:02am
post #47 of 60

Thanks guys you have been great. I now understand a little more about sound.

 

Thing is, any answer given only raises more questions about the other terms in order to explain the things properly (like dB SPL, quantization noise etc), so can some1 recommend me some accessible reading about this audio world? I don't want to get a masters degree, just know how things work and its real life benefits. I have some electronics knowledge so I think I already have some bases to begin with.

 


Edited by vytman - 1/29/12 at 2:44pm
post #48 of 60
Quote:
Originally Posted by vytman View Post

Thanks guys you have been great. I now understand a little more about sound.

 

Thing is, any answer given only raises more questions about the other terms in order to explain the things properly (like dB SPL, quantization noise etc), so can some1 recommend me some accessible reading about this audio world? I don't want to get a masters degree, just know how things work and its real life benefits. I have some electronics knowledge so I think I already have some bases to begin with.

 


The fact that you often have to familarise yourself with such terminology to avoid spending money unneccessarily is testament to the sheer quantity of misinformation in the hobbyfrown.gif
 

 

post #49 of 60
Thread Starter 


 

Quote:
Originally Posted by vytman View Post

Thanks guys you have been great. I now understand a little more about sound.

 

Thing is, any answer given only raises more questions about the other terms in order to explain the things properly (like dB SPL, quantization noise etc), so can some1 recommend me some accessible reading about this audio world? I don't want to get a masters degree, just know how things work and its real life benefits. I have some electronics knowledge so I think I already have some bases to begin with.

 



 

dB (decibel) is the unit used to quantify sound levels relative to a 0dB reference. It's basically volume. SPL stands for Sound Pressure Level.

 

post #50 of 60

^ I think I could be a little clearer concerning decibels.

 

A decibel is a way to express a value relative to another reference value, it is mathematically defined a 10 log ( Value / (Reference Value)), thus when the value you measure is equal to the reference value, it becomes 0 dB.

Decibels are used in a lot of situations.

-  to describe sound pressure levels, in this case the reference value for 0 dB is the limit of audibility, the unit is dB SPL.

- voltage ratios, if the reference voltage is 1 V, it's dBv, if it's 0.775 V, it's dBu

- to describe a level relative the maximum level possible, it's often used for digital signals where the max level is 0 dBFS (for Full Scale) and all other level are relative to this 0 dBFS, noise for 16 bit audio is at -96 dBFS.

 

Anyway, the important thing to remember when thinking about decibels is that you are always considering a ratio.

 

(NB: For field units, it's 20log(V/Vref) instead of 10 log, there's a reason for that, but don't worry about it foo much for now)

post #51 of 60

In short, multiplying by 10 is needed for power (Watts), while a factor of 20 is needed for voltage (Volts) and current (Amperes). This difference is simply because power is proportional to the squared voltage (P=V^2/R) and current (P=I^2*R), and log(x^2) = 2*log(x). For digital audio signal levels, the factor of 20 is used, too, since the signal, once converted to analog and amplified, ultimately controls voltage on the transducer.

 


Edited by stv014 - 1/30/12 at 8:45am
post #52 of 60

Yep, it's only a convention to get the same result for both power and voltage.

post #53 of 60

Thanks again, you guys are great.
 

Quote:
Originally Posted by khaos974 View Post

^ I think I could be a little clearer concerning decibels.

 

Decibels are used in a lot of situations.

-  to describe sound pressure levels, in this case the reference value for 0 dB is the limit of audibility, the unit is dB SPL.

 


What do you mean by "limit of audibility"? In my audio home system I can turn the volume from something like -50dB to +20dB+, how that's apply to what you said?

 

post #54 of 60
Quote:
Originally Posted by Willakan View Post


The fact that you often have to familarise yourself with such terminology to avoid spending money unneccessarily is testament to the sheer quantity of misinformation in the hobbyfrown.gif
 

 



Well, how did you guys learned then? biggrin.gif

post #55 of 60
Thread Starter 


 

Quote:
Originally Posted by khaos974 View Post

^ I think I could be a little clearer concerning decibels.

 

A decibel is a way to express a value relative to another reference value, it is mathematically defined a 10 log ( Value / (Reference Value)), thus when the value you measure is equal to the reference value, it becomes 0 dB.

Decibels are used in a lot of situations.

-  to describe sound pressure levels, in this case the reference value for 0 dB is the limit of audibility, the unit is dB SPL.

- voltage ratios, if the reference voltage is 1 V, it's dBv, if it's 0.775 V, it's dBu

- to describe a level relative the maximum level possible, it's often used for digital signals where the max level is 0 dBFS (for Full Scale) and all other level are relative to this 0 dBFS, noise for 16 bit audio is at -96 dBFS.

 

Anyway, the important thing to remember when thinking about decibels is that you are always considering a ratio.

 

(NB: For field units, it's 20log(V/Vref) instead of 10 log, there's a reason for that, but don't worry about it foo much for now)


^ much better explanation

 

He already seemed confused, so I just gave him the watered down version for simplicity's sake

 

 

post #56 of 60
Quote:
Originally Posted by vytman View Post

Thanks again, you guys are great.
 

Quote:
Originally Posted by khaos974 View Post

^ I think I could be a little clearer concerning decibels.

 

Decibels are used in a lot of situations.

-  to describe sound pressure levels, in this case the reference value for 0 dB is the limit of audibility, the unit is dB SPL.

 


What do you mean by "limit of audibility"? In my audio home system I can turn the volume from something like -50dB to +20dB+, how that's apply to what you said?



Remember when I wrote that decibels meant a ratio compared to a reference value, the scale on your home audio system uses a reference voltage for its 0 dB value, anything is expressed compared to that 0 dB, the 0 dB ref value should be found sowewhere in the provided documentation. The 0 dB corresponds to a certain output voltage which translates into a certain sound pressure level once it's been played through speakers, so +20 dB on the scale means 20 dB SPL louder than the level the sound was being played at when the scale was set on 0 dB.

 

The dB scale on you audio system has an output volatage as a reference, the dB SPL scale has a sound pressure level as a reference.

 

 

Limit of audibility simply refers to the softest sound that can be heard by a healthy human ear at 20.

post #57 of 60

For me the sample rate doesn't as much difference as the word length of the samples.

 

I notice that 88.2/96kHz rates produce a better upper end of the audible spectrum (probably attributed to noise at the upper threshold of accurate sampling with 44.1/48kHz sample rates).

 

Compared to the dynamic range difference between 16 bit and 24 bit the sample rate doesn't matter much to me. I have some 24/96 tracks which are hard to find, 24/192-32/384 tracks are almost impossible to find and really past the point of diminishing return. 

 

Most DACs even upto 24 bit don't even have a SnR level that is at what 24 bit can produce. In terms of headphones and the human ear can't fully take advantage of 16 bit audio let alone 24 bit.

 

The tracks that are released in 24 bit formats tend to be better mastered anyways (usually a lot less compression induced loudness).

post #58 of 60
Quote:
Originally Posted by 65535 View Post

I notice that 88.2/96kHz rates produce a better upper end of the audible spectrum (probably attributed to noise at the upper threshold of accurate sampling with 44.1/48kHz sample rates).


What noise?

post #59 of 60

Aliasing that occurs in frequencies above 22.5kHz which is well above what I or most people can hear, but there are harmonics up there. Wether that is what the reason is I couldn't say, it may just be that I probably was listening to 24/96 vs. 16/44.1 and not 16/44.1 vs. 16/96. 

 

I like 24 bit recordings a lot.

post #60 of 60
Quote:
Originally Posted by 65535 View Post

Aliasing that occurs in frequencies above 22.5kHz which is well above what I or most people can hear, but there are harmonics up there.


That is not a problem caused by the format, though, but rather by low quality DACs or sample rate conversion.

 

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