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Jerry Avins
Guest
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 Posted:
Fri Oct 28, 2005 12:16 am Post subject:
Re: Is the output of an analog filter real or the magnitude? |
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@. wrote:
...
| Quote: | I don't know why you bother. However, it is clear that you are confusing
the real and imaginary components of a complex analytic signal in the time
domain with the real and imaginary components of a frequency response
function.
|
There is no such thing as a complex analytic signal on a single wire
pair. If you think there is, show me.
Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
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Guest
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| Posted:
Sat Nov 05, 2005 8:17 am Post subject:
Re: Is the output of an analog filter real or the magnitude? |
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Jerry Avins <jya@ieee.org> wrote in news:QKmdnQTckaWnzPzeRVn-2w@rcn.net:
| Quote: | @. wrote:
...
I don't know why you bother. However, it is clear that you are
confusing the real and imaginary components of a complex analytic
signal in the time domain with the real and imaginary components of a
frequency response function.
There is no such thing as a complex analytic signal on a single wire
pair. If you think there is, show me.
Jerry
|
I never said there was. The time signal on the single wire pair is the
real part of the complex analytic time signal. But since you don't know
the difference between amplitude an magnitude, it is not surprising that
you are also confused by my replies. Perhaps you should do some reading on
the matter and after you get up to speed we can continue the discussion. |
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Jerry Avins
Guest
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| Posted:
Sat Nov 05, 2005 8:36 am Post subject:
Re: Is the output of an analog filter real or the magnitude? |
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@. wrote:
| Quote: | Jerry Avins <jya@ieee.org> wrote in news:QKmdnQTckaWnzPzeRVn-2w@rcn.net:
@. wrote:
...
I don't know why you bother. However, it is clear that you are
confusing the real and imaginary components of a complex analytic
signal in the time domain with the real and imaginary components of a
frequency response function.
There is no such thing as a complex analytic signal on a single wire
pair. If you think there is, show me.
Jerry
I never said there was. The time signal on the single wire pair is the
real part of the complex analytic time signal.
|
Oh, sure. And the rafters that hold the roof over my head are the real
parts of complex analytic rafters. You're letting your complex analytic
mind dissolve into fantasy.
Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
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Guest
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| Posted:
Sun Nov 20, 2005 1:16 am Post subject:
Re: Is the output of an analog filter real or the magnitude? |
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Jerry Avins <jya@ieee.org> wrote in
news:c7qdnQE3U5ICh_HenZ2dnUVZ_t2dnZ2d@rcn.net:
| Quote: | @. wrote:
Jerry Avins <jya@ieee.org> wrote in news:QKmdnQTckaWnzPzeRVn-2w@rcn.net:
@. wrote:
...
I don't know why you bother. However, it is clear that you are
confusing the real and imaginary components of a complex analytic
signal in the time domain with the real and imaginary components of a
frequency response function.
There is no such thing as a complex analytic signal on a single wire
pair. If you think there is, show me.
Jerry
I never said there was. The time signal on the single wire pair is the
real part of the complex analytic time signal.
Oh, sure. And the rafters that hold the roof over my head are the real
parts of complex analytic rafters. You're letting your complex analytic
mind dissolve into fantasy.
Jerry
|
Ignorance is bliss. You rally need to read some of Dick Heyser's work on
Sound Intensity and Energy-time and the need for complex analytic time
signals having both real and imaginary parts to accurately describe the
physics of the situation. |
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Jerry Avins
Guest
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| Posted:
Sun Nov 20, 2005 9:15 am Post subject:
Re: Is the output of an analog filter real or the magnitude? |
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robert bristow-johnson wrote:
...
| Quote: | i haven't seen the name "Dick Heyser" invoked since the late 80's . Jerry,
there is a story to tell here. Richard Heyser was a well known AES author
and personality, who became President-Elect of the AES circa 1985 and then
died untimely before becoming President, which was quite tragic but
increased his mystique among his disciples.
Heyser invented a way to use what we (DSPers) call "Linear Swept Frequency
Measurements" to measure the response of a loudspeaker in a non-anechoic
environment by using swept tuned bandpass filters to follow the swept
frequency at precisely the right delay to not allow reflections of the
loudspeaker that arrive at a later time and will have a frequency that lies
outside of the swept bandpass. he dubbed it "Time Delay Spectrometry".
|
...
I understand that Hauser's approach inspired a system for seeing through
fog that was the dual of his frequency-domain selectivity. Short pulses
of light -- only a few inches -- are emitted, and the receiving imager
is gated on for an equally brief period at a delay corresponding to a
particular distance. Light scattered back from intervening fog is
ignored. The process repeats at different distances and the images
overlapped. Attenuation is only partly compensated for, but even in
dense fog, penetration is great enough to operate a vehicle at
reasonable speeds. Prototypes were operational at Aberdeen in the late
60s. I don't know what happened since.
Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
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robert bristow-johnson
Guest
|
| Posted:
Sun Nov 20, 2005 9:15 am Post subject:
Re: Is the output of an analog filter real or the magnitude? |
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in article 5DPff.257113$tG2.236585@fe02.news.easynews.com, @. at @. wrote on
11/19/2005 19:41:
| Quote: | Jerry Avins <jya@ieee.org> wrote in
news:c7qdnQE3U5ICh_HenZ2dnUVZ_t2dnZ2d@rcn.net:
@. wrote:
Jerry Avins <jya@ieee.org> wrote in news:QKmdnQTckaWnzPzeRVn-2w@rcn.net:
@. wrote:
...
I don't know why you bother. However, it is clear that you are
confusing the real and imaginary components of a complex analytic
signal in the time domain with the real and imaginary components of a
frequency response function.
There is no such thing as a complex analytic signal on a single wire
pair. If you think there is, show me.
Jerry
I never said there was. The time signal on the single wire pair is the
real part of the complex analytic time signal.
Oh, sure. And the rafters that hold the roof over my head are the real
parts of complex analytic rafters. You're letting your complex analytic
mind dissolve into fantasy.
Jerry
Ignorance is bliss. You really need to read some of Dick Heyser's work on
Sound Intensity and Energy-time and the need for complex analytic time
signals having both real and imaginary parts to accurately describe the
physics of the situation.
|
i haven't seen the name "Dick Heyser" invoked since the late 80's . Jerry,
there is a story to tell here. Richard Heyser was a well known AES author
and personality, who became President-Elect of the AES circa 1985 and then
died untimely before becoming President, which was quite tragic but
increased his mystique among his disciples.
Heyser invented a way to use what we (DSPers) call "Linear Swept Frequency
Measurements" to measure the response of a loudspeaker in a non-anechoic
environment by using swept tuned bandpass filters to follow the swept
frequency at precisely the right delay to not allow reflections of the
loudspeaker that arrive at a later time and will have a frequency that lies
outside of the swept bandpass. he dubbed it "Time Delay Spectrometry". it
was very clever for 1960s analog technology and finally got commercialized
(using a Z-80 CPM based portable computer) by a division of Crown called
Techron. Linear Swept Frequency Measurements can now be done with any DSP
and A/D and D/A combination and compete with the Maximum Length Sequences
method. Heyser wrote for some other audiophile magazines also (i can't
remember the titles).
anyway, a sorta cult following grew around Dick because much of what he was
saying was not understood by a lot of people, including some other big dudes
in the AES (like Stan Lipshitz), but no one considered him a crackpot or
crank, but maybe a little bit like a mysterious genius. sorta like the also
late Michael Gerzon.
anyway, for @.'s information, if the system is linear and time-invariant,
all we need to know is an accurate impulse response (and TDS is a perfectly
good way to get it, but there are other ways) and we can generate any of
those "analytic responses" that Heyser wrote about. i have a lot of respect
for Heyser and his memory, but some of his disciples are a little kooky. i
think they make his contribution to the art into something it never was.
--
r b-j rbj@audioimagination.com
"Imagination is more important than knowledge." |
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Gary Sokolcih
Guest
|
| Posted:
Thu Nov 24, 2005 9:16 am Post subject:
Re: Is the output of an analog filter real or the magnitude? |
|
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robert bristow-johnson <rbj@audioimagination.com> wrote in
news:BFA56279.C4C3%rbj@audioimagination.com:
| Quote: | i haven't seen the name "Dick Heyser" invoked since the late 80's .
Jerry, there is a story to tell here. Richard Heyser was a well known
AES author and personality, who became President-Elect of the AES
circa 1985 and then died untimely before becoming President, which was
quite tragic but increased his mystique among his disciples.
|
An intersting asserion, but one that I doubt you can susbstantiate.
Specifically what is the mystique is it to which you refer, and exactly who
are his so-called deciples?
| Quote: | Heyser invented a way to use what we (DSPers) call "Linear Swept
Frequency Measurements" to measure the response of a loudspeaker in a
non-anechoic environment by using swept tuned bandpass filters to
follow the swept frequency at precisely the right delay to not allow
reflections of the loudspeaker that arrive at a later time and will
have a frequency that lies outside of the swept bandpass. he dubbed
it "Time Delay Spectrometry". it was very clever for 1960s analog
technology and finally got commercialized (using a Z-80 CPM based
portable computer) by a division of Crown called Techron. Linear
Swept Frequency Measurements can now be done with any DSP and A/D and
D/A combination and compete with the Maximum Length Sequences method.
Heyser wrote for some other audiophile magazines also (i can't
remember the titles).
anyway, a sorta cult following grew around Dick because much of what
he was saying was not understood by a lot of people, including some
other big dudes in the AES (like Stan Lipshitz)......
|
Another intersting, but false assertion, especially in light of the fact
that, Vandercooy, one of Lipshit's associates and JAES co-authors,
published in the JAES a detailed analysis of the techinque of time delay
spectrometry technique that Heyser invented. While you may know something
about dsp, you are clearly ignorant of the technique and history of time
delay spectrometry.
| Quote: | anyway, for @.'s information, if the system is linear and
time-invariant, all we need to know is an accurate impulse response
(and TDS is a perfectly good way to get it, but there are other ways)
and we can generate any of those "analytic responses" that Heyser
wrote about.
|
So what. The issue under discussion with not whether or not the analytic
signal can be generated from the measured impulse response. The issue is
whether the signal one sees on an oscilloscope is the real part of the
analytic time signal or, as the idiot Jerry Avins claims, its magnitude.
What do you have to say about this issue?
| Quote: | i have a lot of respect for Heyser and his memory, but
some of his disciples are a little kooky.
|
Perhaps you would care to name a few of his kooky deciples?
i think they make his
| Quote: | contribution to the art into something it never was.
|
You obviously don't know squat about Dick Heyser's contributions and,
intellectually, you aren't even close to being anywhere near his league.
Keep sucking up to bob cain, the lying, hypocritical, sadistic, socipathic,
and technically-inept fraud and watch whatever credibility you still have
left go right down the toilet. |
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robert bristow-johnson
Guest
|
| Posted:
Thu Nov 24, 2005 9:16 am Post subject:
Re: Is the output of an analog filter real or the magnitude? |
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Gary Sokolcih wrote:
| Quote: | robert bristow-johnson <rbj@audioimagination.com> wrote in
news:BFA56279.C4C3%rbj@audioimagination.com:
i haven't seen the name "Dick Heyser" invoked since the late 80's .
Jerry, there is a story to tell here. Richard Heyser was a well known
AES author and personality, who became President-Elect of the AES
circa 1985 and then died untimely before becoming President, which was
quite tragic but increased his mystique among his disciples.
An intersting asserion, but one that I doubt you can susbstantiate.
|
what, that Heyser is dead? that he was President-elect of the AES when
he died? that it was tragic?
| Quote: | Specifically what is the mystique is it to which you refer,
|
that is answered by you below.
| Quote: | and exactly who are his so-called deciples?
|
oh, i dunno. who are those Syn-Aud-Con folk? Don Davis and some
others.
| Quote: | Heyser invented a way to use what we (DSPers) call "Linear Swept
Frequency Measurements" to measure the response of a loudspeaker in a
non-anechoic environment by using swept tuned bandpass filters to
follow the swept frequency at precisely the right delay to not allow
reflections of the loudspeaker that arrive at a later time and will
have a frequency that lies outside of the swept bandpass. he dubbed
it "Time Delay Spectrometry". it was very clever for 1960s analog
technology and finally got commercialized (using a Z-80 CPM based
portable computer) by a division of Crown called Techron. Linear
Swept Frequency Measurements can now be done with any DSP and A/D and
D/A combination and compete with the Maximum Length Sequences method.
Heyser wrote for some other audiophile magazines also (i can't
remember the titles).
anyway, a sorta cult following grew around Dick because much of what
he was saying was not understood by a lot of people, including some
other big dudes in the AES (like Stan Lipshitz)......
Another intersting, but false assertion, especially in light of the fact
that, Vandercooy, one of Lipshitz's associates and JAES co-authors,
published in the JAES a detailed analysis of the techinque of time delay
spectrometry technique that Heyser invented. While you may know something
about dsp, you are clearly ignorant of the technique and history of time
delay spectrometry.
|
snicker. say Gary, did you know that i also published twice in JAES
about it? (admittedly they were both in the form of Letters, the first
in response to Greiner's "Digital Approach to TDS" article.) i was the
first (at least in the AES context, i won't claim to be) to provide the
concise derivation (much simpler than John's) of the output of an LTI
due to input that is TDS (otherwize known as "linear-swept frequency
measurements"). Christopher Struck had the same idea and published an
AES preprint with the same derivation about a year later. maybe you
should read it. it's so simple, i remember even posting it here on
comp.dsp.
| Quote: | anyway, for @.'s information, if the system is linear and
time-invariant, all we need to know is an accurate impulse response
(and TDS is a perfectly good way to get it, but there are other ways)
and we can generate any of those "analytic responses" that Heyser
wrote about.
So what?
|
it means that, providing we are looking at an LTI system, once we know
the impulse response, we know *everything* we need to know about the
system. we know how that LTI system will respond to *any* input. from
that impulse response, we can deduce what the frequency response is
(magnitude and phase), what the waterfall plots look like (given some
parameters of the waterfall), what the analytic response is, what the
"energy-time curve" is.
| Quote: | The issue under discussion with not whether or not the analytic
signal can be generated from the measured impulse response. The issue is
whether the signal one sees on an oscilloscope is the real part of the
analytic time signal or, as the idiot Jerry Avins claims, its magnitude.
What do you have to say about this issue?
|
do you know what a Strawman is, Gary? In response to Andrew's post,
it's pretty clear that Jerry understood the semantic issue with the
word "magnitude" for what i think "instantaneous value" would have been
more clear. you've been fucking with the semantics, too, Gary. i
don't give a rat's ass if it's an "ANALOG" filter or not, the output of
an LTI system is the convolution of the input with the impulse
response. no more and no less. i dunno what Jerry meant with some Mr.
"Hauser", or light scattering or Aberdeen but i'm not worried.
now, in the spirit of Heyser or even Andrew Duncan (haven't seen him in
print for a decade or more), you can construct an conceptual input that
is
x(t) = delta(t) + j*( 1/(pi*t) )
which is the "analytic impulse" as coined by Duncan (i believe) and if
your ANALOG filter is a REAL filter (that is none of its components
have complex or imaginary values), then what would mathematically come
out is
y(t) = h(t) + j*Hilbert{ h(t) }
which, of course, is the analytic signal (or is it "analytical", this
jargon always gets mixed up, also with "analytic function" in the
complex variables discipline) of the impulse response. and the
magnitude of this would be your "Energy-time curve":
ETC = |y(t)| = | h(t) + j*Hilbert{ h(t) } |
the cool thing about that ETC (in contrast to rectifying and filtering
h(t)) is that you have an envelope to h(t) but, at least in the
positive frequencies, it corresponds to a complex signal that has the
same spectrum as h(t). rectifying and smoothing h(t) would not have
the same spectrum in any way and would represent a loss of information.
anyway, with a real impulse response (that you can measure with any
variety of techniques), you can construct that same ETC in the mind of
the computer and plot it. no big deal. TDS is not necessary.
| Quote: | i have a lot of respect for Heyser and his memory, but
some of his disciples are a little kooky.
Perhaps you would care to name a few of his kooky deciples?
|
perhaps, you?
| Quote: | i think they make his contribution to the art into something it never was.
You obviously don't know squat about Dick Heyser's contributions and,
intellectually, you aren't even close to being anywhere near his league.
|
oh, gee, my self confidence is just so devastated. (so answered is
your first question above.)
| Quote: | Keep sucking up to bob cain, the lying, hypocritical, sadistic, socipathic,
and technically-inept fraud and watch whatever credibility you still have
left go right down the toilet.
|
hey Bob, we just gotta stop meeting like this. your hickies are
starting to show.
--
r b-j
"nawleege is gud." |
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