What's the use of a 192 kHz sample rate?
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From: Jerry Avins on 4 May 2008 10:04 Manolis C. Tsakiris wrote: ... > in DVDs the audio signals are modulated digital pulses (and not analog > waveforms), such as PCM, and their spectrum is no longer that of an > acoustical signal (20Hz-20kHz), justifying the need for a higher sampling > rate. That sounds like doubletalk to me. Would you please rephrase it in simpler terms? A few therefores and becauses would help. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
From: Jerry Avins on 4 May 2008 10:13 rickman wrote: ... > You can poo-poo this sort of evaluation. But that doesn't make you > right. Do you have any "proof" that no one can hear the difference? > Do you even know what the differences are that I was talking about? What is your opinion of the benefit of using 0-0 gauge gold-plated Litz wire or flat braid for speaker cables? How about CD demagnetizers? There are many listeners' claims for theose also. ... Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
From: Jerry Avins on 4 May 2008 10:22 robert bristow-johnson wrote: ... > now, in *processing* sounds with some nasty non-linearities in the > process, it very well may be necessary to upsample to 192 kHz or > higher to do that non-linear processing, and when it is done, LPF to > 20 kHz and downsample back to 48 kHz. but, except for experimental > purposes, 192 kHz storage or transimssion is not necessary. You're wearing an engineer's hat. Now try to think like a marketeer. :-) Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
From: Jerry Avins on 4 May 2008 10:37 Randy Yates wrote: > rickman <gnuarm(a)gmail.com> writes: >> [...] >> When I press the keys on the right, I >> hear more of a click than a ping (maybe it's the piano)! > > Then you can no longer hear up to 4186 Hz. I can hear all but the top two notes on a piano. My hearing is now down at 4 KHz 40 dB in one ear and 45 in the other. > http://en.wikipedia.org/wiki/Piano_key_frequencies > > You are free to think what you want about hearing. I choose to side with > objective measurements verifying again and again over several decades > the same conclusions rather than a few crackpot audiophools that claim > they're different without any supporting objective evidence. > > And even if one or two actually could hear beyond 20 kHz, they're the > Robert Wadlow's of the audio world - should we start building houses > with 10-foot ceilings because 1 out of a billion will be over 8 feet > tall? Why not, is you can sell them at a premium? My house sits on a third-acre lot. Some houses built near here look like they have a quarter acre footprint. Who needs a McMansion for three people? Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
From: Jerry Avins on 4 May 2008 10:48
Piergiorgio Sartor wrote: > Randy Yates wrote: > >> The curve on p.20 of >> >> http://www.dohc.ie/publications/pdf/hearing.pdf?direct=1 >> >> indicates that, even for young adults, sound at <20 kHz is >> inaudible. Based on this, a 44.1 kHz sample rate should be ample. > > The problem might be that a "sound" is not only > perceived with ears, but with the full body. > > One specific issue are the sudden transitions of > pitches that real world instruments can create, > and, possibly, are picked up by different means. > For example, the sound waves going through the > skull, brain tissue and then to ears (from inside) > are "distorted" and, maybe, remodulated, so that > a person *could* receive "signals" (from real > instruments), which otherwise would be wiped out > by sampling low-pass filter, in case of 44.1KHz > sampling rate. > > That's the theory. > Is this true? I don't know, maybe, maybe not. > There are people swearing this is the case, others > say that's nonsense. > There are people citing Dolby technologies taking > into account these alternate perception paths, but > I could not find any real reference. > > Nevertheless, one thing is sure (and proven) sound > waves are not only "eared", they're generally > perceived by the full body, but the studies I know > always refer to bass and not to ultrasounds. I recently had my hearing tested, both through the ear canals and via bone conduction. The results match to within a few dB, indicating that my loss of cochlear or nerve, rather than associated with eardrum or ossicles. I don't think the alternate paths account for much in general. Jerry -- Engineering is the art of making what you want from things you can get. ����������������������������������������������������������������������� |