HiFi vs. Computer

[Guest]

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"Tim Martin" <tim2718281@ntlworld.com> wrote in message
news:4QVpe.7653$8m5.699@newsfe5-gui.ntli.net...
>
> "Wessel Dirksen" <wdirksen@gmail.com> wrote in message
>
news:1118245554.711573.288300@g14g2000cwa.googlegroups.com...
>
> > Simpler yet, infinity is even ruled out by the very
vehicle of sound
> > propagation itself which can never be infinite. If
anything is acoustic
> > in nature, it can't be of infinite bandwidth otherwise
it would violate
> > Newton's basic law of conservation of energy. To say
that any "sound"
> > has infinite bandwidth is to say that inertia doesn't
exist.
>
> Sorry, I don't see why there being no lower limit to time
resolution in an
> analog signal would violate conservation of energy.

A lower limit to time resolution is a consequence of the
signal having finite duration. If the signal went on
indefinitely it would have no lower limit.

If the signal went on indefinitely and had finite energy in
all or most finite time segments, then the total signal
would have infinite amounts energy.

Now if the presence of infinite amounts of energy doesn't in
some sense violate the law of conservation of energy... ;-)

 

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<dpierce@cartchunk.org> wrote in message
news:1118263580.233046.252730@g47g2000cwa.googlegroups.com...

> What one CAN say, most definitely, is that the number of possible paths
> the signal CAN take between the two points is limited by the interval
> between those two points and the bandwidth of the signal. Make the
> bandwidth narrow enough, or make the two points close enough, and the
> signal is uniquely constrained. At that point, then, if you "sample"
> the signal at those intervals, you can have complete knowledge of the
> signal wihout having INFINITE knowledge of the signal.

Great, a comment with some substance.

OK, let's suppose our signal is a 1kHz sine wave, followed by a period of
silence, followed by a 1kHz sine wave. The amplitude of the sine wave is
the minimum that can be represented in our digital scheme. And let's
suppose our sampling rate is 50000 times a second .... that is, one sample
every 20 microseconds..

Now, I think that an analog signal with a silence of 200 microseconds will
result in the same digital representation as an analog signal with a silence
of 201 microseconds.

Do you agree or not?

Tim

 

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Tim Martin wrote:
> <dpierce@cartchunk.org> wrote in message
> news:1118318316.768496.179950@o13g2000cwo.googlegroups.com...
>
> > Wrong, because the signal you describe CANNOT be represented in a
> > system with finite bandwidth, a fundamental principle you abjectly
> > refuse to grasp. More importantly, you've described a signal that
> > you cannot even create in the real universe.
>
> So, you're saying I cannot create a signal comprising a 1kHz sine wave with
> small amplitude, followed by a period of silence, followed by a 1kHz sine
> wave with small amplitude.

No, you're saying that you can.

So, prove us wrong. Produce for us this signal EXACTLY as you have
described it (ignoring the fact, for the moment, that your description
of such signal is QUITE inexact) through any means at your disposal.
By signal, I don't mean an equation (continuous or otherwise), or
a drawing on a piece of paper or any such dodge. I mean a signal.
It can be acoustical, electrical, mechanical, what have you.

By the way, as you HAVE provided a woefully incomplete description,
how about we better define the signal? How long is the 1 kHz
signal? Exactly when does it end? How long is the silence? Exactly
when does it end? How silent is silent? How long is the second period
of the 1 kHz since wave? How small is its amplitude?

Fine, you say it can, so produce it.

Let us know.

 

[Guest]

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On Thu, 09 Jun 2005 11:35:28 GMT, "Tim Martin"
<tim2718281@ntlworld.com> wrote:

>
>"Wessel Dirksen" <wdirksen@gmail.com> wrote in message
>news:1118245554.711573.288300@g14g2000cwa.googlegroups.com...
>
>> Simpler yet, infinity is even ruled out by the very vehicle of sound
>> propagation itself which can never be infinite. If anything is acoustic
>> in nature, it can't be of infinite bandwidth otherwise it would violate
>> Newton's basic law of conservation of energy. To say that any "sound"
>> has infinite bandwidth is to say that inertia doesn't exist.
>
>Sorry, I don't see why there being no lower limit to time resolution in an
>analog signal would violate conservation of energy.

That's because you don't understand the subject. No lower limit to
time resolution = infinite bandwidth = infinite energy.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

 

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<dpierce@cartchunk.org> wrote in message
news:1118318316.768496.179950@o13g2000cwo.googlegroups.com...

> Wrong, because the signal you describe CANNOT be represented in a
> system with finite bandwidth, a fundamental principle you abjectly
> refuse to grasp. More importantly, you've described a signal that
> you cannot even create in the real universe.

So, you're saying I cannot create a signal comprising a 1kHz sine wave with
small amplitude, followed by a period of silence, followed by a 1kHz sine
wave with small amplitude.

Tim

 

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"Arny Krueger" <arnyk@hotpop.com> wrote in message
news:L-2dnVo0xeD_ozXfRVn-sg@comcast.com...
> If the signal went on indefinitely and had finite energy in
> all or most finite time segments, then the total signal
> would have infinite amounts energy.
>
> Now if the presence of infinite amounts of energy doesn't in
> some sense violate the law of conservation of energy... ;-)

Of course the duration cannot be infinite, ie. longer than the universe
existence.

MrT.

 

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On Thu, 09 Jun 2005 16:08:47 GMT, "Tim Martin"
<tim2718281@ntlworld.com> wrote:

>
><dpierce@cartchunk.org> wrote in message
>news:1118318316.768496.179950@o13g2000cwo.googlegroups.com...
>
>> Wrong, because the signal you describe CANNOT be represented in a
>> system with finite bandwidth, a fundamental principle you abjectly
>> refuse to grasp. More importantly, you've described a signal that
>> you cannot even create in the real universe.
>
>So, you're saying I cannot create a signal comprising a 1kHz sine wave with
>small amplitude, followed by a period of silence, followed by a 1kHz sine
>wave with small amplitude.

If you allow the sine wave a finite period of attack and decay, and
the 'silence' to have a noise floor, then of course you can.
Otherwise, no one can.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

 

[Guest]

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On Thu, 09 Jun 2005 11:48:47 GMT, "Tim Martin"
<tim2718281@ntlworld.com> wrote:

>
>OK, let's suppose our signal is a 1kHz sine wave, followed by a period of
>silence, followed by a 1kHz sine wave. The amplitude of the sine wave is
>the minimum that can be represented in our digital scheme. And let's
>suppose our sampling rate is 50000 times a second .... that is, one sample
>every 20 microseconds..
>
>Now, I think that an analog signal with a silence of 200 microseconds will
>result in the same digital representation as an analog signal with a silence
>of 201 microseconds.
>
>Do you agree or not?

No. You're describing an analogue waveform ending towards infinite
bandwidth. It can't exist in analogue or digital represention

(If it COULD, you'd be thanking the digital system for ironing out
such glitches, not complaining about low resolution

 

[Guest]

Archived from groups: rec.audio.tech (More info?)

On Thu, 09 Jun 2005 16:08:47 GMT, "Tim Martin"
<tim2718281@ntlworld.com> wrote:

>So, you're saying I cannot create a signal comprising a 1kHz sine wave with
>small amplitude, followed by a period of silence, followed by a 1kHz sine
>wave with small amplitude.

Not if you want that period of silence to be as short as we've been
discussing. No you can't. You can describe it as a theoretical
possibility. But, lacking resources tending to the infinite, you
can't create it.

 

[Engineer]

Archived from groups: rec.audio.tech (More info?)

"calmar" <calmar@calmar.ws> wrote in message
news:slrnd9k37v.4ve.calmar@news.calmar.ws...
> Hi,
>
> I'm wondering, how a good computer with a good graphic card + good
> speakers can compare to a good HiFi System?
>
> Since good soundcards can be quite expensive, and that only for the
> card
> itself, I would suspect, that that good computer/soundcard and good
> speaker combo can be as good as a good HiFi System?
>
> So I really don't know much about these things.
>
>
> Thanks for any hints.
>
> calmar

For a long time now I have plugged my various PC sound card outputs
(line level, not speaker output) into the AUX input of "surplus"
stereo receivers (1970's to 80's vintage, around 15 to 25 wpc) and
used whatever "spare" stereo speakers that were around at the time.
The results have been generally good for CD's played on the PC. But
all this stuff is in in the office so I can't do an A-B comparison
with my main system.
Anyway, try it. What can you lose?
Cheers,
Roger