Super high definition digital audio

[XB-70 Valkyrie]

In comparing digital audio players, I've been seeing that in addition to supporting lossless formats like FLAC, WAV et al., some are touting playback of very high sampling rates and word lengths such as 196K/24 bit. Obviously this greatly exceeds CD quality, but how common are such ultra-high resolution recordings, and where does one download them? I guess I'm just out of the loop on this one. (I really have not gotten into downloading yet--I have so many CDs I don't even have time to listen to)

Also, do you hear much of a difference between these ultra high def recordings and standard CD? From my own limited experience of listening to DAT recordings done at (I believe) 48K and 20 bit, the sound quality was amazing and certainly better than standard CD.

[Brian]

The only 24/192 download I'm aware of, personally, is this French organ recital from BIS, which does indeed sound spectacular, but I haven't played it on high-end stereo equipment (only good headphones).

[drogulus]

     You could use them to calibrate equipment or measure noise from rectifier diodes. I'm thinking about putting FREDs (Fast Recovery Epitaxial Diodes) in my Vox amplifier. It's not an expensive mod and not the sort to hurt collector value.

[Gurn Blanston]

     You could use them to calibrate equipment or measure noise from rectifier diodes. I'm thinking about putting FREDs (Fast Recovery Epitaxial Diodes) in my Vox amplifier. It's not an expensive mod and not the sort to hurt collector value.

I'll talk it over with my dog and see if she wants to hear some Messiaen; 'cause I would sure as hell never hear any sort of difference. And of course, I let the experts handle my FREDs... 

Also, do you hear much of a difference between these ultra high def recordings and standard CD? From my own limited experience of listening to DAT recordings done at (I believe) 48K and 20 bit, the sound quality was amazing and certainly better than standard CD. 

This will inevitably deteriorate into a loud and messy argument over whether you can even hear a difference, and the end result is that for every person who insists on having had a musically induced orgasm while listening to their high-end unit, there will be 35 who say the orgasm was caused by mainly digital manipulation...

[71 dB]

Also, do you hear much of a difference between these ultra high def recordings and standard CD? From my own limited experience of listening to DAT recordings done at (I believe) 48K and 20 bit, the sound quality was amazing and certainly better than standard CD.

44.1 KHz/16 bit audio has 100 % of the resolution needed in domestic listening. For comparison, the dynamic range of vinyl is about 10 bits.

Higher sampling rate makes it possible to have simpler anti-aliasing and reconstruction filters.

Higher bit depth is useful when recording sounds because there is plenty of dynamic headroom for very loud sounds.

Domestic listening requires about 90 dB on dynamics (eg. SPL between 20 dB and 110 dB). 16 bit audio can provide that. Dithering allows signal levels even 20 dB lower than the noise levels.

The frequency range of children's hearing is about 20 Hz - 20 kHz. Shannon's theorem (I believe only a small persentage of people understand sampling theory) says bandlimited signals can be recorded completely if the sampling rate is at least twice the highest signal frequency. Digital audio never represents the "staircase" waveforms shown to people. Such sharp staircases would require infinite bandwidth. Even analog audio is bandlimited. Reconstruction filters shape the output of DACs so that the result imitates the original (analog) signal precisely (depending on the quality of the DAC).

DAT supports 32 kHz/12 bits, 32/16 bits, 44.1 kHz/bits and 48 kHz/16 bits. The "superiority" of DAT you have experienced (recordings of what? CDs? Radio transmissions?) has been mostly placebo-effect. Perhaps the DAT had better DAC and less jitter than your CD player?

Low sampling rate has advantages too. The slower ADCs and DACs work, the better accuracy they have making the convensions. Having signal frequencies above 20 kHz cut away prevents distortion in audio amps that are optimized for frequencies below 20 kHz. It might be difficult to believe, but 96 kHz audio can sound worse than 44.1 kHz audio! Even if it sounds the same, it takes much more storage space.

Digital technology has evolved over the decades. 44.1 kHz/16 bit and high quality DACs of today quarantee "perfect" sound and more is actually even less.