[link] 24/192 Music Downloads ...and why they make no sense

My favorite part from the article...

... *bam*... and that's why we're all here.

Quote:

Originally Posted by uzi 

My favorite part from the article...

 

 

... *bam*... and that's why we're all here.

Nice. Also, I raced here with the article in my copy-and-paste slot ... and was beaten to it ... twice.

Fantastic article, clear and concise.

Very good article, one with which I agree in general terms.

Another advantange of 24-bit depth that he does not mention is that, like the engineers recording and mixing, the user also needs bits to play with if s/he wants to alter the digital signal at home before playback.  One such example is for digital volume control where 16-bit depth quickly runs into theoretical and audible problems.  This is one reason why, if you want to control volume digitally at the source, you should use a DAC that can take a 24-bit depth (dithered) signal.

All in all, nothing more than 24-bit/48kHz is needed.  Anything more won't make an audible difference, and it may actually stress some equipment into distorting the signal.

As I've argued on this forum before, one is likely to get more handsome returns on $$ spent putting that money into speakers/headphones.

"Neither audio transducers nor power amplifiers are free of distortion, and distortion tends to increase rapidly at the lowest and highest frequencies. If the same transducer reproduces ultrasonics along with audible content, harmonic distortion will shift some of the ultrasonic content down into the audible range as an uncontrolled spray of intermodulation distortion products covering the entire audible spectrum. Harmonic distortion in a power amplifier will produce the same effect. The effect is very slight, but listening tests have confirmed that both effects can be audible"

The article is full of insights applicable not only to the issues of sampling rates and bit-depths, but also to the issue of amplification.  The author identifies intermodulation distortion in a power amplifier as something that is audible.  This insight is pertinent to the discussion at hand, but also pertinent to the issue of passive or active speakers.  Yet another audible fault of passive systems is that an amplifier tasked with reproducing the entire frequency range will introduce intermodulation distortion as it is called to amplify a 50Hz, 500Hz and 15,000Hz signals concurrently.  The bass range will introduce distortion into the midrange, and so will the treble.  This problem is reduced, if not altogether avoided in active systems in which the amplifiers only reproduced a limited frequency range, and where the amplifiers are isolated from one another.

As the articles makes clear, intermodulation distortion is real and audible.  Passive systems that rely on a single amp for the entire frequency rage suffer too from this weakness, and from its audible effects.  If you believe that intermodulation distortion is real, audible and best avoided or mitigated, then you must also admit that active systems suppress it more comprehensively--by mere virtue of its fundamentally different system configuration--than an active system.  In the quest for minimal distortion and coloration, this article shows by deduction that active systems are superior to passive ones in this regard.

Quote:

Originally Posted by Mauricio 

 

Another advantange of 24-bit depth that he does not mention is that, like the engineers recording and mixing, the user also needs bits to play with if s/he wants to alter the digital signal at home before playback.  One such example is for digital volume control where 16-bit depth quickly runs into theoretical and audible problems.  This is one reason why, if you want to control volume digitally at the source, you should use a DAC that can take a 24-bit depth (dithered) signal.

This is wrong, or at least not necessarily right. The bit length of a data source need have nothing to do with the bit length of a chip's registers. 16 bit data can be loaded into 32 bit registers, or handled by a system where 16 bit data always has a 32 bit result. Or everything can be converted to a floating point format if that's how the chip swings.

(And yes, I am a programmer, and yes I've worked with DSP chips. But no, I don't know what the chip in any particular PC audio system or PMP does.)

My understanding is that every 6dB digital volume reduction is equivalent to losing one bit of bit depth.  The signal is still 16-bits, but the it gets passed to the DAC as a padded 24-bit signal.  As such, as a 24-bit signal, you can reduce volume and lose bits still, but the effects won't be noticeable.  This is what I've gleaned from discussions about digital volume control.

Quote:

Originally Posted by scuttle 

This is wrong, or at least not necessarily right. The bit length of a data source need have nothing to do with the bit length of a chip's registers. 16 bit data can be loaded into 32 bit registers, or handled by a system where 16 bit data always has a 32 bit result. Or everything can be converted to a floating point format if that's how the chip swings.

 

(And yes, I am a programmer, and yes I've worked with DSP chips. But no, I don't know what the chip in any particular PC audio system or PMP does.)

Sadly Windows almost always truncates audio data with its digital volume control, and other similar digital solutions(safe for some of the newer DACs I think) has been less than perfect too(according to manufacturers and various test equipment). I think 24 bit has more advantages in USB audio because of the way how USB handles usb data(according to Benchmark),losing quite a few bits through usb truncation would not matter and also you may apply many more VSTi/DSP techniques without losing significant quality.

On another note, Maurico, pursue a topic where it is meant to be pursued ......

very informative article, opened my eyes

Quote:

Originally Posted by firev1 

 

 

 

On another note, Maurico, pursue a topic where it is meant to be pursued ......

 

 

 

Where do you propose I pursue the topic?  In the portable headphones channel?