What's the use of a 192 kHz sample rate?

On May 3, 3:28 am, Randy Yates <ya...@ieee.org> wrote:
> rickman <gnu...@gmail.com> writes:
> > If it really is a waste of time and money to use 192 kHz ADC and DAC,
> > why do you think they would do it?
>
> Greed. They think that the general public is dumb enough to buy into
> the lie that they really need such a system and would then spend lots of
> money repurchasing what they already have.

I'm curious, how do you know what unnamed people are thinking?  My
understanding is that regardless of what frequencies acoustic testing
says that people can hear, audiophiles can hear the difference between
many of these "wasteful" features and otherwise adequate audio
systems.

I have known people who worked on professional equipment.  The
extremes that they have design in are all audible to the buyers of
such systems.  In the audio sections of the equipment they use 15 volt
rails or even higher, just to increase the SNR when the noise floor
can't be lowered anymore.  They totally eliminate all digital clocks
from any circuit near the audio section to prevent noise injection.
From what I have seen, they use more extreme measures in high end
audio than is used in sensitive military radio gear which is trying to
get over 140 dB of SNR!

I am not going to try to tell someone else what they can and can't
hear.  I know that my hearing has dropped of dramatically to where I
can no longer hear the 15 kHz emitted by TVs and I'm not sure I can
hear the high notes on a piano.  When I press the keys on the right, I
hear more of a click than a ping (maybe it's the piano)!  But that
doesn't mean that there aren't others who can hear the distortion
created by the anti-alias filters used when the ADC and DAC run at
44.1 kHz.

On Sat, 3 May 2008 05:11:53 -0700 (PDT), rickman <gnuarm@gmail.com>
wrote:

>On May 3, 3:28 am, Randy Yates <ya...@ieee.org> wrote:
>> rickman <gnu...@gmail.com> writes:
>> > If it really is a waste of time and money to use 192 kHz ADC and DAC,
>> > why do you think they would do it?
>>
>> Greed. They think that the general public is dumb enough to buy into
>> the lie that they really need such a system and would then spend lots of
>> money repurchasing what they already have.
>
>I'm curious, how do you know what unnamed people are thinking?  My
>understanding is that regardless of what frequencies acoustic testing
>says that people can hear, audiophiles can hear the difference between
>many of these "wasteful" features and otherwise adequate audio
>systems.
>

Utter nonsense - unless of course you can cite some proper tests.

>I have known people who worked on professional equipment.  The
>extremes that they have design in are all audible to the buyers of
>such systems.  In the audio sections of the equipment they use 15 volt
>rails or even higher, just to increase the SNR when the noise floor
>can't be lowered anymore.  They totally eliminate all digital clocks
>from any circuit near the audio section to prevent noise injection.
>From what I have seen, they use more extreme measures in high end
>audio than is used in sensitive military radio gear which is trying to
>get over 140 dB of SNR!
>

More nonsense. I have worked on many radio systems, both military and
civil, and a typical target SNR for these radios is in the region of 6
to 10dB.

>I am not going to try to tell someone else what they can and can't
>hear.  I know that my hearing has dropped of dramatically to where I
>can no longer hear the 15 kHz emitted by TVs and I'm not sure I can
>hear the high notes on a piano.  When I press the keys on the right, I
>hear more of a click than a ping (maybe it's the piano)!  But that
>doesn't mean that there aren't others who can hear the distortion
>created by the anti-alias filters used when the ADC and DAC run at
>44.1 kHz.

Doesn't mean they can either. That isn't a piece of logic that
commutes.

d

-- 
Pearce Consulting
http://www.pearce.uk.com

rickman <gnuarm@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. 

  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?
-- 
%  Randy Yates                  % "How's life on earth? 
%% Fuquay-Varina, NC            %  ... What is it worth?" 
%%% 919-577-9882                % 'Mission (A World Record)', 
%%%% <yates@ieee.org>           % *A New World Record*, ELO
http://www.digitalsignallabs.com

On May 3, 1:49 am, "Green Xenon [Radium]" <gluceg...@excite.com>
wrote:
> rickman wrote:
> > On May 3, 12:41 am, "Green Xenon [Radium]" <gluceg...@excite.com>
> > wrote:
> >> Hi:
>
> >> Why does DVD-Audio use 192 kHz sample rate? What's the advantage over
> >> 44.1 kHz? Humans can't hear the full range of a 192 kHz sample rate?
>
> >> On average, what is the minimum sample rate for a guy in his early to
> >> mid 20s who likes treble?
>
> >> I agree there are a small percentage of humans who can hear above 20
> >> kHz. However, DVD-audio uses a sample-rate of 192 kHz which allows a
> >> maximum frequency of 96 kHz. There is no known case of any human being
> >> able to hear sounds nearly as high as 96 kHz. I can agree with 48 kHz
> >> sample rate and even 96 kHz sample-rate [maybe], but 192 kHz is just stupid.
>
> >> So whats the justification fur using 192 kHz? If you ask me, its just a
> >> total waste of bandwidth and energy. Any proof to the contrary?
>
> >> Please correct me if I'm wrong but AFAIK, its a waste of time, money,
> >> energy to move to 192 kHz.
>
> >> Thanks,
>
> >> Radium
>
> > If it really is a waste of time and money to use 192 kHz ADC and DAC,
> > why do you think they would do it?  Don't you think the people
> > designing DVD equipment understand the economics of consumer
> > products?
>
> > Try to think about it and see if you can come up with a couple of
> > reasons yourself.  I'll be interested in hearing what you think.
>
> > Rick
>
> No. I can't think of any reason to use a 192 kHz sample-rate. It is
> really overkill. If you think otherwise, the please explain why.

This thread is one that could be thought provoking.  But I would like
to see *you* do some of the thinking.  What is the difference between
the way a player is designed using a 44.1 (or 48) kHz sample rate and
a 192 kHz sample rate?  What does that difference do to the analog
signal that is produced?  How might that difference sound to a
listener?

This is not rocket science.  The differences may not be audible to
you, but they exist and they are well understood.  I'll give you a
hint; do you know what phase distortion is?

Also, I would like you to explain what is wasteful about a 192 kHz
sample rate.  How much money does it cost to use 192 kHz instead of 96
kHz or 44.1 kHz.  What time is involved?  How much extra energy does
the higher sample rate use?  Are you aware that there are virtually
infinite amounts of bandwidth not being used every second?  What
difference does it make if DVDs underutilize a bit more?

I am working on a circuit that uses a 192 kHz CODEC to process 1 kHz
signals.  Of course I am not using it at 192 kHz, so am I wasting
bandwidth still?  Or by using an 8 kHz sample rate, am I conserving
bandwidth and deserve recognition? I like the idea of being "pink" (as
in noise) by conserving precious bandwidth.  Actually, I can't wait to
get the thing out on the open road and open it up!  I want to put the
pedal to the metal and sample at the full 192 kHz to see just what
sort of analog bandwidth these CODECs really have!  I'm not actually
sure they will produce higher than about 40 kHz at the analog output.
I'll have to hack away the 1 pole filter I added to the input and
output.  It limits the frequency range to a paltry 30 kHz or so.  I
may not hear the difference, but my scope can "see" it!

BTW, if you aren't looking at your monitor or you aren't sitting close
enough to see every pixel, are you wasting bandwidth on your video
signal?  Actually, that is an excellent analogy.  If you limit the
video bandwidth to half the pixel rate, what difference will you see
on a CRT display?

Finally, why do you see the advantage of using 96 kHz sample rate and
not 192 kHz?  Isn't 96 kHz wasting bandwidth?

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.

bye,

-- 

piergiorgio

On May 3, 5:42 pm, Piergiorgio Sartor
<piergiorgio.sartor.this.should.not.be.u...@nexgo.REMOVETHIS.de>
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.
>
> bye,
>
> --
>
> piergiorgio

   I agree that humans cant hear above 20k rate

   Its not always about what you hear or percieve with your body.

   Its also about how you store data.

   here is an simplified analogy.

   say you need 44.1k samples per second to hear properly. If the disk
is corrupted with scrathes
   and 1 samples in his region are lost your sound is distorted or
lost for that period of time.
   Now if there are 196k samples even if (196/44.1) samples are lost
there is no difference to what you
   hear.

   DVD's come wih high density of data due to this they are highly
vulnerable to scratches this can be avoided
   with better waveform matching achieved by high sampling rate.

On May 3, 6:16 pm, rajesh <getrajes...@gmail.com> wrote:
> On May 3, 5:42 pm, Piergiorgio Sartor
> <piergiorgio.sartor.this.should.not.be.u...@nexgo.REMOVETHIS.de>
> 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.
>
> > bye,
>
> > --
>
> > piergiorgio
>
>    I agree that humans cant hear above 20k rate
>
>    Its not always about what you hear or percieve with your body.
>
>    Its also about how you store data.
>
>    here is an simplified analogy.
>
>    say you need 44.1k samples per second to hear properly. If the disk
> is corrupted with scrathes
>    and 1 samples in his region are lost your sound is distorted or
> lost for that period of time.
>    Now if there are 196k samples even if (196/44.1) samples are lost
> there is no difference to what you
>    hear.
>
>    DVD's come wih high density of data due to this they are highly
> vulnerable to scratches this can be avoided
>    with better waveform matching achieved by high sampling rate.

I am ot sure about the math, its worh doing again. This is one
argument in favour of
high sample rate.

On Fri, 02 May 2008 21:41:34 -0700, "Green Xenon [Radium]"
<glucegen1@excite.com> wrote:

>Why does DVD-Audio use 192 kHz sample rate? What's the advantage over 
>44.1 kHz? Humans can't hear the full range of a 192 kHz sample rate?

Some objective reasons:

1) It's used in professional audio to accommodate nonlinear processing
such as dynamic range compression.  The gain changes imposed by
dynamic range compression are mathematically equivalent to modulation.
Modulation produces sidebands.  Those sidebands *may* alias, under the
right conditions.  There have been some published papers on this, but
I cannot lay my hands on any examples at the moment.  Though this may
justify 96 kHz, it probably doesn't justify 192.

2) There's some evidence that humans' ability to hear high frequency
transient signals exceeds their ability to hear high frequency steady
state signals.  I can only offer anecdotal evidence:  I can hear
steady state tones up to about 16 kHz.  I have a SynAudCon CD that
contains tone bursts consisting of 6 cycles of a windowed (appears to
be Hann) sinusoid at frequencies up to beyond the limit of my hearing.
Though I perceive them as clicks, I definitely hear them.  Again,
though this may justify 96 kHz, it probably doesn't justify 192.  

3) Others less verifiable, such as the claimed audibility of pre-ring
associated with linear or nonminimum phase anti-imaging filters.
Basically the higher sampling rate may allow more options here.  If
true, this *might* justify 192 kHz.  Maybe.

Some subjective reasons:

1) Marketing.

2) Bragging Rights.

3) Superstition.

4) Magical Thinking.

5) Self-Delusion.

6) Mass Hypnosis.

Personally I think that something like 64 kHz (possibly 128 kHz for
mastering) would have solved all of these problems adequately.

-- Greg

Randy,

> Greed. They think that the general public is dumb enough to buy into the
> lie that they really need such a system and would then spend lots of money
> repurchasing what they already have.

LOL, you nailed it man. Same with music, where they hope you'll buy all the
same titles again to play on your new unnecessary hardware.

Besides the obvious waste, as Radium pointed out, this nonsense has been
discredited fully:

Audio Critic summary of the AES hi-res fallacy article:
http://theaudiocritic.com/blog/index.php?op=ViewArticle&articleId=41&blogId=1

More from the authors themselves:
http://www.bostonaudiosociety.org/explanation.htm

Paul Lehrman commenting in Mix magazine:
http://mixonline.com/recording/mixing/audio_emperors_new_sampling/index1.html

Nobody can hear, or perceive, or be influenced by ultrasonic content, even
if they think they can. Here's my best explanation for why people sometimes
report hearing differences even when none can possibly exist:

http://www.ethanwiner.com/believe.html

> 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?

More to the point, even if a few people really can just barely detect when 
frequencies above 20 KHz are removed, who cares? Just because someone can 
perceive 21 KHz doesn't mean that music they hear must contain those 
frequencies to be satisfying.

--Ethan 

On May 3, 8:22 am, nos...@nospam.com (Don Pearce) wrote:
> On Sat, 3 May 2008 05:11:53 -0700 (PDT), rickman <gnu...@gmail.com>
> wrote:
>
> >On May 3, 3:28 am, Randy Yates <ya...@ieee.org> wrote:
> >> rickman <gnu...@gmail.com> writes:
> >> > If it really is a waste of time and money to use 192 kHz ADC and DAC,
> >> > why do you think they would do it?
>
> >> Greed. They think that the general public is dumb enough to buy into
> >> the lie that they really need such a system and would then spend lots of
> >> money repurchasing what they already have.
>
> >I'm curious, how do you know what unnamed people are thinking?  My
> >understanding is that regardless of what frequencies acoustic testing
> >says that people can hear, audiophiles can hear the difference between
> >many of these "wasteful" features and otherwise adequate audio
> >systems.
>
> Utter nonsense - unless of course you can cite some proper tests.

And what do you base this statement on?  I don't have any "proper"
studies.  I am referring to a conversation with a friend who worked in
the field.  He couldn't hear the difference, but his customers could.
If they came out with a product that used a "lesser" technique,
without *knowing* what technology was behind it they would reject the
system as not being good enough.  If they didn't know anything about
the methods, they only had their ears to judge the equipment.  Since
they are paying serious bucks (>$100,000 some 20 years ago) for these
systems, they have *NO* reason to buy racks of gear that is any better
than a lower price system.  BTW, this was professional equipment, not
the home stuff with oxygen free speaker wires and such.

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?


> >I have known people who worked on professional equipment.  The
> >extremes that they have design in are all audible to the buyers of
> >such systems.  In the audio sections of the equipment they use 15 volt
> >rails or even higher, just to increase the SNR when the noise floor
> >can't be lowered anymore.  They totally eliminate all digital clocks
> >from any circuit near the audio section to prevent noise injection.
> >From what I have seen, they use more extreme measures in high end
> >audio than is used in sensitive military radio gear which is trying to
> >get over 140 dB of SNR!
>
> More nonsense. I have worked on many radio systems, both military and
> civil, and a typical target SNR for these radios is in the region of 6
> to 10dB.

My bad, I used the wrong term, it should have been 140 dB signal
strength.  Yes, I need to indicate what the reference is, but I don't
recall if it was dBmW or dBW, a 30 dB difference.


> >I am not going to try to tell someone else what they can and can't
> >hear.  I know that my hearing has dropped of dramatically to where I
> >can no longer hear the 15 kHz emitted by TVs and I'm not sure I can
> >hear the high notes on a piano.  When I press the keys on the right, I
> >hear more of a click than a ping (maybe it's the piano)!  But that
> >doesn't mean that there aren't others who can hear the distortion
> >created by the anti-alias filters used when the ADC and DAC run at
> >44.1 kHz.
>
> Doesn't mean they can either. That isn't a piece of logic that
> commutes.

I didn't say it proves that others can.  What logic are you talking
about?  I am simply saying that you shouldn't judge what others can
perceive by what you can or even what the general public can according
to "proper tests".

I'm not trying to "prove" anything.  I am presenting information which
you can consider and believe or can ignore.  But you can't say my
statements are false unless you have some information to "prove" they
are.  Human hearing is not a microphone connected to an amplifier.  It
is a very complex process which even includes the brain and we
certainly don't understand it completely.