advertisement


192 khz 32 bit is not enough! 384 khz is the new

Way back in the 90's Rob Watts reckoned 24/384 was better than the best turntable/arm/cartridge combo's. The sound was well rounded with none of the problems associated with either TT's or CD. Of course we still have the problem of getting recording up to 24/192 let alone 32/384!!!
 
And it will be a long time before 384 khz / 32 bit is the norm for music. Still interesting.
It will probably never be the norm since it's completely pointless for recording and playback of music. The technical performance of a good A/D or D/A system is roughly equivalent to 20 or 21 bits.
384kS/s represents a bandwidth of ~192kHz, but the human auditory system is limited to ~20kHz so there is no reason to record/play ultrasonic frequencies (and most microphones/speakers won't do it anyway).

Way back in the 90's Rob Watts reckoned 24/384 was better than the best turntable/arm/cartridge combo's. The sound was well rounded with none of the problems associated with either TT's or CD.
You can't really say that 24/384 or CD have a "sound". Bit depth and sample rate only tell you the limits in dynamic range and bandwidth.
With proper implementation there are usually no audible differences between digital formats.

And all of the commonly used digital formats are technically superior to vinyl.
 
Very good points...

The technical performance of a good A/D or D/A system is roughly equivalent to 20 or 21 bits.

Make that a very good ADC / DAC. Actually delivering that kind of level of performance is hard, for mundane reasons. Example 1, the inherent (Johnson) noise of a single 1kohm resistor in an audio bandwidth of 20Khz is already at about 20-21bits below line level of 2vrms, so extraordinary care has to be taken all the way through the design. Reason 2 - That's about the limit of microphones themselves, too, for similar reasons. Not that general studio mics have much response past 18Khz...

IIRC Keith Howard has done some work which shows that so far, there's not much HD music out there with audio content significantly beyond about 15bits as it is.

Mastering is where the big difference are, always has been - and unfortunately even the highest res possible is meaningless when the mastering / artistic choice/compression is duff.
 
Make that a very good ADC / DAC.
True. Getting that kind of performance in practice is very difficult, and not really necessary anyway.

IIRC Keith Howard has done some work which shows that so far, there's not much HD music out there with audio content significantly beyond about 15bits as it is.
I don't think there are any commercially available recordings in any format with even close to 16 bits of dynamics.
The most dynamic recordings of classical music may use up to 12-13 bits in extreme cases, but those are pretty rare.

Mastering is where the big difference are, always has been - and unfortunately even the highest res possible is meaningless when the mastering / artistic choice/compression is duff.
Exactly!
 
24/192 is fast becoming the 'HD' or 'HD-Ready' of the DAC world. Very few devices currently support it, but the number is growing fast . . . shall we compile a list?
 
True. Getting that kind of performance in practice is very difficult, and not really necessary anyway.

I don't think there are any commercially available recordings in any format with even close to 16 bits of dynamics.
The most dynamic recordings of classical music may use up to 12-13 bits in extreme cases, but those are pretty rare.


Exactly!

All they see are larger numbers and it's Pavlovian...
 
Anything beyond 24bit is meaningless. However, I really love the sound of 96k+ transfers of analogue masters.

The 96k mastering of A Love Supreme is the prime example of this. I just love the sound, and the tone of the instruments just shines through compared to the CD
 
Maybe you should ask yourself what you are expecting to hear from the so called HD audio.

The best ACD (analog to digital) so far is 18 bits =) I still can't understand how they are selling 24 bit material ripped "directly from the master tapes" =)

Cheers,
Rudy

PS. Not to mention that all delta sigma DAC sound awful. But this ofc is only my humble opinion =)
 
...
384kS/s represents a bandwidth of ~192kHz, but the human auditory system is limited to ~20kHz so there is no reason to record/play ultrasonic frequencies (and most microphones/speakers won't do it anyway).
...
You can't really say that 24/384 or CD have a "sound". Bit depth and sample rate only tell you the limits in dynamic range and bandwidth.
...

There is one other aspect you may have missed about the advantage of higher sample rates.

While it is true that we generally can not hear SINGLE FREQUENCIES above 20kHz, you will know from Fourier Analysis that higher harmonics will improve the response of dynamic rises and increase temporal accuracy.

Doubling the sample rate will also double the start-stop timing accuracy of the musical envelope.

The question is though - if we can only hear up to 20,000Hz, can we only perceive differences in timing accuracies within its inverse - 0.05ms? [changed from 0.5ms, I need to improve my decimal place counting]

Andrew
 
The question is though - if we can only hear up to 20,000Hz, can we only perceive differences in timing accuracies within its inverse - 0.5ms?

Andrew


The two things are totally unrelated. The frequency limitations of our auditory system has no bearing on our ability to differentiate the "timing" of an event in the absolute sense.

Plus I would add, that much store is put on our hearing being limited from 20hz - 20kz but two points:

Said range is only an "average", not an absolute. Despite what people believe there are people who can hear outside this range. Very certainly a very small percentage, but the fact remains they exist.

Said range is what we can perceive through our auditory system. It is not the limit of what we can perceive with our body as a whole, most obvious example is how you can feel vibrations far lower than 20hz when heavy lorry passes your window. The same is true of frequencies higher than 20khz. A Russian study once showed that a human subject was able to perceive frequencies of up to 200khz when the transducer was attached directly to the skull.

Given enough stimulus our body is perfectly capable of perceiving frequencies above and below 20hz - 20khz.
 
192/32 = a high resolution format where most of what is stored is thermal noise of the microphones being used.
 
you will know from Fourier Analysis that higher harmonics will improve the response of dynamic rises and increase temporal accuracy.
?

Doubling the sample rate will also double the start-stop timing accuracy of the musical envelope.
No it won't.

The question is though - if we can only hear up to 20,000Hz, can we only perceive differences in timing accuracies within its inverse - 0.5ms?
You missed an order of magnitude.

Paul
 
The question is though - if we can only hear up to 20,000Hz, can we only perceive differences in timing accuracies within its inverse?
The inter-aural timing differences used to judge direction are known to be as small as 10uS. We certainly don't hear up to 100Khz.
 
192/32 = a high resolution format where most of what is stored is thermal noise of the microphones being used.

It could be argued that to be truly "hi-fi" any reproduction system should be capable of recording the noise floor of the noisiest part of the recording chain, (using the lowest noise recording chain equipment available - not low quality kit), if that means recording the noise of the microphones then so be it. There is plenty of evidence that introducing noise increases our ability to resolve low level detail, but irrespective of that you can never know you've recovered 100% of the detail available in the signal unless you've recorded to levels below the noise floor.
 


advertisement


Back
Top