A while back I made a reference to a woolly memory of something I had read
in HFW to do with Tim de P's views on bitrates and their vinyl equivalents
and said I would post a reference to it, if it ever appeared. Well it's
popped up out of the blue and is, of course, nothing like I remembered it.

It's on 2 pages of the April 2004 edition:

http://www.apah69.dsl.pipex.com/keit.../article01.jpg

plus the top left paragraph he

http://www.apah69.dsl.pipex.com/keit.../article02.jpg


The 'bitrates' are nothing to do with vinyl it seems - simply Tim De P's
idea of a minimum requirements for digital to come even close.

Now, having said all this, I still have another memory that there are some
pretty impressive figures somewhere that compare vinyl 'information flow'
very favourably with digital bitrates, but I've no idea where from and have
no intention of trying to find out. - I don't need to, I *know* there's more
detail in vinyl played on decent equipment. I can prove that to myself
anytime I feel the need with a number of CD/LP pairings.

(I've even had people here, pointing it out to *me* on my own sodding
kit...!! ;-)

Keith G wrote:

The 'bitrates' are nothing to do with vinyl it seems - simply Tim De P's
idea of a minimum requirements for digital to come even close.

OMFG. 400kHz sampling?

I dont think even a bat could hear the top end of the frequecy range
that allows.

"Ian Molton" almost choked on his de-caffinated espresso...

OMFG. 400kHz sampling?

I dont think even a bat could hear the top end of the frequecy range
that allows.

But the point isn't the maximum frequency, it's the content of the audible
waveform . . . .

Remember the idea . . . increased frequency of sampling allows you to
reconstruct a waveform closer to the original analogue form . . . .??

And let's face it, a lot of 'musicality' is based on harmonics and the
interplay of notes, so you really do want a pretty big sampling rate to make
sure you catch it all . . .

________
Geoff B

"New Geoff" m.gjb SPHERICAL wrote in message
...

"Ian Molton" almost choked on his de-caffinated espresso...

OMFG. 400kHz sampling?

I dont think even a bat could hear the top end of the frequecy range
that allows.

But the point isn't the maximum frequency, it's the content of the audible
waveform . . . .



Molton, eh?

(I wondered what tit had made that remark!! :-)

"New Geoff" m.gjb SPHERICAL wrote in message

"Ian Molton" almost choked on his de-caffinated espresso...

OMFG. 400kHz sampling?

I dont think even a bat could hear the top end of the frequecy range
that allows.

But the point isn't the maximum frequency, it's the content of the
audible waveform . . . .

Remember the idea . . . increased frequency of sampling allows you to
reconstruct a waveform closer to the original analogue form . . . .??


That idea is well-known to be false.

And let's face it, a lot of 'musicality' is based on harmonics and the
interplay of notes, so you really do want a pretty big sampling rate
to make sure you catch it all . . .

Dumb, dumb, dumber!

New Geoff wrote:
"Ian Molton" almost choked on his de-caffinated espresso...

OMFG. 400kHz sampling?

I dont think even a bat could hear the top end of the frequecy range
that allows.


But the point isn't the maximum frequency, it's the content of the audible
waveform . . . .

Remember the idea . . . increased frequency of sampling allows you to
reconstruct a waveform closer to the original analogue form . . . .??

Up to a point, yes. but as someone else here pointed out - over ~8kHz
humans cant distinguish the difference between sine, triangle, sawtooth,
square at all. thats well below 22kHz.

Ian Molton wrote:
New Geoff wrote:

"Ian Molton" almost choked on his de-caffinated espresso...

OMFG. 400kHz sampling?

I dont think even a bat could hear the top end of the frequecy range
that allows.



But the point isn't the maximum frequency, it's the content of the
audible
waveform . . . .

Remember the idea . . . increased frequency of sampling allows you to
reconstruct a waveform closer to the original analogue form . . . .??


Up to a point, yes. but as someone else here pointed out - over ~8kHz
humans cant distinguish the difference between sine, triangle, sawtooth,
square at all. thats well below 22kHz.

I think the point made was over 8k sine and square was indistinguisable.
I would expect someone who's hearing went beyond 16k to tell the rest apart.

--
Nick

"Nick Gorham" wrote in message


Ian Molton wrote:

Up to a point, yes. but as someone else here pointed out - over ~8kHz
humans cant distinguish the difference between sine, triangle,
sawtooth, square at all. thats well below 22kHz.

I think the point made was over 8k sine and square was
indistinguisable.

...to review, that's because the first harmonic that is present in the square
wave is at 24 Khz.

The triangle, being symmertrical also has its first present harmonic at 24
KHz.

The sawtooth lacks half-wave symmetry and therefore has substantial content
at 16 KHz.

I would expect someone who's hearing went beyond 16k to tell the rest
apart.

That is not obvious, because masking can prevent people from perceiving the
lack of signal at frequencies that are lower than the limit of hearing for
pure high frequency sine waves. However, the second harmonic of a 8 KHz
sawtooth is probably strong enough to be noticable.

Actually doing this experiment might be non-trivial because it can be hard
to get really good sawtooth waves to work with.

In article , Ian Molton wrote:
New Geoff wrote:
"Ian Molton" almost choked on his de-caffinated espresso...

OMFG. 400kHz sampling?
I dont think even a bat could hear the top end of the frequecy range
that allows.

But the point isn't the maximum frequency, it's the content of the audible
waveform . . . .

Remember the idea . . . increased frequency of sampling allows you to
reconstruct a waveform closer to the original analogue form . . . .??

Up to a point, yes. but as someone else here pointed out - over ~8kHz
humans cant distinguish the difference between sine, triangle, sawtooth,
square at all. thats well below 22kHz.

Stepping back, the work of Fletcher & Munson and many others seems to
remain at the core of human hearing research. Indeed about 20 kHz
clearly remains the accepted upper limit for what we can hear.

There have been a few papers on human perception of ultrasound but
compared to the bulk of the literature it is clear that these are
exploring the margins rather than the fundamentals.

A quick search reveals a couple of examples:

- http://home.dmv.com/~tbastian/files/ultrsonc.txt

- http://www.hearultraquiet.com/Pages/...%20Hearing.pdf

It certainly seems that there may be some perception of ultrasound but
just how much that changes how we experience music and other audio is
still not clear. Those who say 44.1 kHz sampling is not enough may
possibly end up with an objective case. Nevertheless, just how much
difference it makes in reality to our experience is a long way from
being established.

We may want to go that way, but it is clear that compared to 44.1 kHz
the effect of upping the sample rate will be distinctly marginal rather
than fundamental.

--
John Phillips

On Wed, 10 Nov 2004 20:52:55 +0000 (UTC), "New Geoff" m.gjb SPHERICAL
wrote:


"Ian Molton" almost choked on his de-caffinated espresso...

OMFG. 400kHz sampling?

I dont think even a bat could hear the top end of the frequecy range
that allows.

But the point isn't the maximum frequency, it's the content of the audible
waveform . . . .

Remember the idea . . . increased frequency of sampling allows you to
reconstruct a waveform closer to the original analogue form . . . .??

Whoever came up with that 'idea' doesn't understand sampling theory.

And let's face it, a lot of 'musicality' is based on harmonics and the
interplay of notes, so you really do want a pretty big sampling rate to make
sure you catch it all . . .

If you can't hear it, it doesn't matter. Go learn some basics about
digital audio, or you'll sound just as idiotic as 'crazy Tim'.
--

Stewart Pinkerton | Music is Art - Audio is Engineering