[dB Cooper]

The conclusions of the study discussed in the hydrogen audio forum are pretty close to my own highly subjective and unscientific listening impressions. I am therefore inclined to assume they are fairly accurate 

I have been listening a lot lately to the BBC3 Radio stream (320K AAC) and it sounds pretty damn good to me fwiw

[festuss]

It's science in action.  Doesn't sell full page ads in Stereophile and other assorted marketing papers. Science just ain't as much fun if ya can't have mystical unexplainable reality. What wall outlet are you listening to?

[Napalm]

Yeah, those guys at Stereophile never can get science right, we know here from reputable sources like Speedskater that a CD contains "all the audible information", and from Monty that "there are no steps" on a DAC output, yet no matter how many CD players / DACs they have tried, the Stereophile folks always get outputs like the one in figure 6 here:

http://www.stereophile.com/content/nad-m51-direct-digital-da-converter-measurements

Man, those folks will never learn.....

 

[JohnR]

The waveform in Figure 6 is due to quantization, not to sampling....

[Napalm]

The waveform in Figure 6 is due to quantization, not to sampling....

They're both present in all DACs. An expert like Monty should have known. Showing me a video with a full dynamic range periodic signal, fudging the fact that there are analog filters involved there, and concluding that DACs have no "steps" in their outputs and will perfectly reproduce the original signal within the 20Hz-20kHz is either dumb or disingenuous.

As for the forum comments that 24 bits doesn't bring anything "audible" over 16 bits, they're not much better either, even a half deaf listener will be able to ABX the signals in fig 6 vs fig 7 in the Stereophile article.

[JohnR]

Um... the point being made at that point in the video is that a discrete-time signal is not a "staircase." Discretization and quantization are two different things.

[Napalm]

Um... the point being made at that point in the video is that a discrete-time signal is not a "staircase."

It's not a sine wave either. It's just numbers.

What he's showing there is a method of reconstruction of signal from its time discrete samples.

He measures at the low-pass filter outputs while talking about "DAC" (actually he specifically mentions that "there are no other steps involved than ADC and DAC). Next time please measure at the DAC chip pins or mention the presence of said filter. Don't fudge it.

[JohnR]

My recollection of the video is that he is discussing the nature of a discrete-time signal and what it represents, not any specific method of D-A conversion. What's present on the DAC chip pins depends on how the continuous signal is reconstructed and isn't actually that relevant to the point.

[Napalm]

My recollection of the video is that he is discussing the nature of a discrete-time signal and what it represents, not any specific method of D-A conversion. What's present on the DAC chip pins depends on how the continuous signal is reconstructed and isn't actually that relevant to the point.

Then we're probably watching different videos. The one I saw had Monty demonstrating a HP signal generator, a Lenovo computer with soundcard, a blue box he was calling "DAC" and a Tektronix oscilloscope and how they all worked together in displaying a signal with no steps. Pretty specific setup I'd say.

[Speedskater]

Monty @ xiph  has a paper and two videos.

24/192 Music Downloads ...and why they make no sense
http://people.xiph.org/~xiphmont/demo/neil-young.html

Video Episode 1: A Digital Media Primer for Geeks
http://xiph.org/video/vid1.shtml

Video Episode 2: Digital Show & Tell
http://xiph.org/video/vid2.shtml

[Napalm]

Monty @ xiph  has a paper and two videos.

24/192 Music Downloads ...and why they make no sense
http://people.xiph.org/~xiphmont/demo/neil-young.html

"here is no point to distributing music in 24-bit/192kHz format. Its playback fidelity is slightly inferior to 16/44.1"

Some people think that MP3 is even better:

http://radar.oreilly.com/2009/03/the-sizzling-sound-of-music.html

[Speedskater]

"here is no point to distributing music in 24-bit/192kHz format. Its playback fidelity is slightly inferior to 16/44.1"

Some people think that MP3 is even better:
http://radar.oreilly.com/2009/03/the-sizzling-sound-of-music.html

Try:

More Evidence that Kids (American and Japanese) Prefer Accurate Sound Reproduction
http://seanolive.blogspot.com/2012_05_01_archive.html

[Napalm]

Obviously they haven't tested on Monty.

[Davey]

Dan Lavry has a few White Papers on his website that might help understanding.

He would actually argue that "Hirez" decreases audio quality.  Oh my goodness. 

http://www.lavryengineering.com/lavry-white-papers/

Cheers,

Dave.

[Napalm]

Dan Lavry has a few White Papers on his website that might help understanding.

He would actually argue that "Hirez" decreases audio quality.  Oh my goodness. 

http://www.lavryengineering.com/lavry-white-papers/

Cheers,

Dave.

He's actually advocating for 96kHz sampling rate not 44.1kHz. Check the paper titled "The Optimal Sample Rate For Quality Audio".

He seems to think that correct reproduction of sounds beyond 20kHz up to some 40-50kHz does make a (positive) difference and a 96kHz sampling rate with a 40-45kHz low pass filter would be the ideal arrangement.

This is pretty much in agreement with what some audiologists have found:

http://www.tinnitusjournal.com/detalhe_artigo.asp?id=109