Comment about speaker cables/interconnects

[Martin]

I recently changed my speaker cable setup and was very surprised at
the difference in the sound. Basically I moved from having
entry-level Van-Den-Hull skyline cables single-wired to my speakers to
bi-wiring with the Skylines on the woofers and Kimber-Kables 4TC for
the tweeters. I was rather astounded at the difference in the sound.
To be honest I was not expecting much change, if any and only did the
upgrade because of a very good deal on the 4TC. Instead I am now very
convinced that cabling considerations may be, although not the most
important aspect, essential to any system and not something to be
ignored.

Here is my pseudo-scientific explaniation.

A few years ago I had a summer job of network support for a small
office. At the time There were about 40 computer workstations with
about 4 printers. One of my jobs was to set it up so that all of the
workstations would have access to a printer. This required the
purchasing of a lot of serial and parallel cables to attatch computers
to printer-sharing boxes.

The use of high quality cabling was ABSOLUTLY essential for this
purpose. Quite simply, using generic cables more than about 2m was
impossible for parallel printer cables. There was to much noise and
signal loss for the succesful and reliable transmission of data.
However, by using much more expensive shielded low capacitance cables
runs could be as long as 10m or even 15m.

Although serial cables (much lower speed signals) were not as finicky,
there were still issues with long runs with cheap cabling. Often I
had to reduce the data speed from 128kb/s to 64kb/s

What does all of this have to do with audio cables you may ask.
Everything. Cables essentially serve as carriers of data.

Assuming as a baseline the bandwidth of a cd (44000*16bits per channel
= 704 kb/s) the amount of data being transmitted is very considerable.
if one sample has a value of 5024 then that exact value must be what
is found at the other end of the interconnect/cable. If the value
recorded at the other end is 5024 +/- 1 then we are losing almost 2
bits of resolution on the sound or a drop in signal to noise of 12db.
Since the CD specification came from studies of human hearing this
loss of two bits is definetly noticable.

Transmitting 704kb/s over a serial connection would be quite a trick.
It can be done but only if care is taken into the way that the signal
is transmitted. Obviously this represents a much lower data rate than
ethernet connection but we must also consider that the type of signal
is very different. Speaker cables and interconnects can't use
modulation of high frequency signels(measured in Mhz and gHz), Rather
the method of signal tranmission is more like amplitude modulation
with relatively low (measured in kHz) to extremely low frequencies
(measured in Hz), where microvolts may represent the difference
between 16 bits and 14 bits of data being transmitted.

With speaker cables the difference is even more profound. Not only
must the source generate this signals with considerable voltage and
current, but the speaker's themselves the recipients are also acting
as sources of noise being transmitted back down the line. I would
suggest that there is a significant amout of data distortion present
even when using the finest amplifiers with excellent short cables.

As I said I only begain thinking about this after noticing a huge
difference to the sound of my system after changing the speaker
cables. Now I am just tring to come up with the theory to explain my
observations. Since I am somewhat familiar with the limitations of
cabling in other applications (computer data transmission) I am trying
to look at the mystery of the audable differences of cables from a
data point of view.

My System

Source:Cambridge Audio D300SE
Pre:Adcom GFP-555 MKII
Power:Bryston 3BST
Speakers:Energy Exl-26
Interconnects:Van-Den-Hull D300SE MKIII
Cables Top : Kimber 4TC
Cables Bottom : VanDenHull Skyline

[Stewart Pinkerton]

On 7 Sep 2003 19:28:04 GMT, (Martin) wrote:

<snip of irrelevant stuff about parallel printer cables>

>What does all of this have to do with audio cables you may ask.
>Everything. Cables essentially serve as carriers of data.

No cables serve as carriers of *signals*. The nature of those signals
may vary enormously.

>Assuming as a baseline the bandwidth of a cd (44000*16bits per channel
>= 704 kb/s) the amount of data being transmitted is very considerable.

No, it's *negligible* when compared with say digital video.

> if one sample has a value of 5024 then that exact value must be what
>is found at the other end of the interconnect/cable. If the value
>recorded at the other end is 5024 +/- 1 then we are losing almost 2
>bits of resolution on the sound or a drop in signal to noise of 12db.
> Since the CD specification came from studies of human hearing this
>loss of two bits is definetly noticable.
>
>Transmitting 704kb/s over a serial connection would be quite a trick.

Oh, really? It's done evry day over considerable distances in studios
all around the world, and no bits are dropped.

>It can be done but only if care is taken into the way that the signal
>is transmitted. Obviously this represents a much lower data rate than
>ethernet connection but we must also consider that the type of signal
>is very different. Speaker cables and interconnects can't use
>modulation of high frequency signels(measured in Mhz and gHz), Rather
>the method of signal tranmission is more like amplitude modulation
>with relatively low (measured in kHz) to extremely low frequencies
>(measured in Hz), where microvolts may represent the difference
>between 16 bits and 14 bits of data being transmitted.

You are totally confusing digital and analogue signal here, with no
apparent relevance to audio.

>With speaker cables the difference is even more profound. Not only
>must the source generate this signals with considerable voltage and
>current, but the speaker's themselves the recipients are also acting
>as sources of noise being transmitted back down the line.

What 'noise'? Do you mean back-emf from the drivers? This isn't noise,
this is simply part of the system operating correctly.

> I would
>suggest that there is a significant amout of data distortion present
>even when using the finest amplifiers with excellent short cables.

I can inform you that no such distortion exists at a level above 160dB
below 10 volts rms.

>As I said I only begain thinking about this after noticing a huge
>difference to the sound of my system after changing the speaker
>cables.

Now *that* is a claim which simply can *not* be supported by any known
comparison, if properly conducted, i.e. level-matched double-blind
protocol.

>Now I am just tring to come up with the theory to explain my
>observations.

First, try making better observations.

> Since I am somewhat familiar with the limitations of
>cabling in other applications (computer data transmission) I am trying
>to look at the mystery of the audable differences of cables from a
>data point of view.

There's no mystery - such differences only exist inside your head.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

[Richard D Pierce]

On 7 Sep 2003 19:28:04 GMT, (Martin) wrote:

Much myth and techinal nonsense.

> What does all of this have to do with audio cables you may ask.
> Everything. Cables essentially serve as carriers of data.

Yes, but the definiton of data changes dramtically depending
upon the domain you are in.

> Assuming as a baseline the bandwidth of a cd (44000*16bits per channel
> = 704 kb/s) the amount of data being transmitted is very considerable.

Yes, and is fully encompassed, by its very definition, in a
continuous-represented signal whose bandwidth is approximately
20 kHz and whose dynamic range is around 96 dB.

You are confusing information content and data rate.

> if one sample has a value of 5024 then that exact value must be what
> is found at the other end of the interconnect/cable. If the value
> recorded at the other end is 5024 +/- 1 then we are losing almost 2
> bits of resolution on the sound or a drop in signal to noise of 12db.

Simply not correct.

> Since the CD specification came from studies of human hearing this
> loss of two bits is definetly noticable.

False, the CD specification did not come from staudies of human
hearing. The specifics of CD specification came from the
predominant storage medium used for mastering that predated the
CD, i.e., video recorders hooked to A/D and D/A converters
determined the sample rate of 44,100 samples/second, and 16 bits
is a convention that existed for data storage LONG before the
CD.

That the specification ALSO happens to allow storage of audio
over a bandwidth and dynamic range sufficient as a distribution
media satisfyinng auditory criteria is comething else.

> Transmitting 704kb/s over a serial connection would be quite a trick.

Excuse me? It's done routinely all the time and has been done
routinely and without error for several decades.

> It can be done but only if care is taken into the way that the signal
> is transmitted. Obviously this represents a much lower data rate than
> ethernet connection but we must also consider that the type of signal
> is very different. Speaker cables and interconnects can't use
> modulation of high frequency signels(measured in Mhz and gHz), Rather
> the method of signal tranmission is more like amplitude modulation
> with relatively low (measured in kHz) to extremely low frequencies
> (measured in Hz), where microvolts may represent the difference
> between 16 bits and 14 bits of data being transmitted.

Sorry, but this is just technical nonsense, and no disrespect is
intended. First, analog signals as you describe have been
trivially transmitted over substantial distances without any of
the problems you claim. Indeed, in the fields of biomedicine,
physics, chemistry and others, signals FAR more fragile than
what you are talking about here have been routinely propogated
error free over long distances under worse conditions than you
will find in domestic listening situations without the losses
you claim are inherent.

Second, you seem not to understand at all the difference between
a signal and the information content of the signal. The two do
NOT put the same demands on the transmission medium if you
switch form a continuous signal to its discrete representation.
The bandwidth for the latter is required to unambiguously
differentiate logic states.

> With speaker cables the difference is even more profound. Not only
> must the source generate this signals with considerable voltage and
> current, but the speaker's themselves the recipients are also acting
> as sources of noise being transmitted back down the line.

No, they are not. This is a very common, very pervasive and very
wrong myth on several fronts. First, where is the source of this
energy? The amplifier. The model you describe is simply the
behavior of resonant systems, be they electrical or mechanical.
A speaker does not act any more as a "noise generator" than does
a simply RLC resonant circuit, despite some stupendously
uninformed pronouncements to the contrary in the high-end press.
Second, even considering the speaker as an independent source of
noise, consider the Thevenin equivalent of its source generator
with respect to the effective load, i.e., the amplifier output,
where that source impedance is a half dozen ohms, and the load
is a small fraction of an Ohm. How much attenuation results?

> I would
> suggest that there is a significant amout of data distortion present
> even when using the finest amplifiers with excellent short cables.

You may suggest all you want. "significant amount of data
distortion" is something that is trivial to quantify, yet no one
has EVER demonstrated such distortion exists. WHy? Becuase it
DOESN'T exist.

> As I said I only begain thinking about this after noticing a huge
> difference to the sound of my system after changing the speaker
> cables.

Well, again with no intent at disrespect, your thinking has led
you quite far down the wrong path. Your explanation about data
rate that leads to the premise of data distortion is simply
contrary to the behavior of signals and cables.

> Now I am just tring to come up with the theory to explain my
> observations.

You have made a change and you seem to have noticed a
difference. You have a "theory" about "data distortion."

Fine. In order for a theory to be at all useful, it needs to be
testable. I am not going to argue with your observation that you
seem to have heard a difference, rather on your rationalization
of the difference. You claim something about "data distortion."
Well, if the signal IS so distorted, a simple null test will
either support or refute your theory's validity on its face.
SImply compare the input to the cable to its output with a
system whose smallest resolvable change is smaller than your
claimed distortion. If a difference is measured, then chalk one
up for your theory. If none is measured, it's a clear blow
against it.

Well, indeed, such measurements HAVE been made, and not a single
cable of even remotely competent construction has exhibited
differences even remotely approaching the levels you are
claiming. That would suggest your theory is wrong.

The confusion between information content and data rate itself
that is the assunmed basis for your theory is itself on very
shakey ground.

--
| Dick Pierce |
| Professional Audio Development |
| 1-781/826-4953 Voice and FAX |
| |

[Lou Anschuetz]

(Richard D Pierce) wrote in
:

> Richard D Pierce ) wrote:
> (extensive snipping)
> : You have made a change and you seem to have noticed a
> : difference. You have a "theory" about "data distortion."
>
> : Fine. In order for a theory to be at all useful, it needs to be
> : testable. I am not going to argue with your observation that you
> : seem to have heard a difference, rather on your rationalization
> : of the difference. You claim something about "data distortion."
> : Well, if the signal IS so distorted, a simple null test will
> : either support or refute your theory's validity on its face.
> : SImply compare the input to the cable to its output with a
> : system whose smallest resolvable change is smaller than your
> : claimed distortion. If a difference is measured, then chalk one
> : up for your theory. If none is measured, it's a clear blow
> : against it.
>
> : Well, indeed, such measurements HAVE been made, and not a single
> : cable of even remotely competent construction has exhibited
> : differences even remotely approaching the levels you are
> : claiming. That would suggest your theory is wrong.
>
> : The confusion between information content and data rate itself
> : that is the assunmed basis for your theory is itself on very
> : shakey ground.
>
I agree with almost everything you've said :)

OTOH, I can understand how he comes to the conclusions he
comes to. As someone with 25 years in IT, I have thrown away dozens
of supposedly competently designed SCSI/serial
cables that don't work. SCSI cables in particular are darn
hard to to get right for the newer higher speeds - and it
all seems to come down to how the cable(s) is insulated.

I also agree that this doesn't necessarily have anything to do
with audio transmission. However, IMHO, this business about
insulation continues to bedevil me. Since it does play havoc
with digital signal transmission, it seems to me hard to leap
to an absolute conclusion that it has no effect in the analog
audio world. No hard science on this yet, but it is a very active
field of research...
--
Lou Anschuetz,
Network Manager, CMU, ECE Dept.

[Stewart Pinkerton]

On 10 Sep 2003 15:47:47 GMT, Lou Anschuetz > wrote:

>As someone with 25 years in IT, I have thrown away dozens
>of supposedly competently designed SCSI/serial
>cables that don't work. SCSI cables in particular are darn
>hard to to get right for the newer higher speeds - and it
>all seems to come down to how the cable(s) is insulated.
>
>I also agree that this doesn't necessarily have anything to do
>with audio transmission. However, IMHO, this business about
>insulation continues to bedevil me. Since it does play havoc
>with digital signal transmission, it seems to me hard to leap
>to an absolute conclusion that it has no effect in the analog
>audio world. No hard science on this yet, but it is a very active
>field of research...

It's certainly *not* an active field of research for audio purposes.
All that research was done many *decades* ago in the communications
and measurement industries, and there are certainly significant
effects at multi MegaHertz frequencies. Drop the frequency by a factor
of a thousand, and you also drop the effects by a factor of a
thousand........

At audio frequencies, you will *never* measure artifacts in cables
above -140dB referred to a 10 vrms signal, and usually much lower than
that, right at the -160dB or so limit of the measuring gear.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

[Lou Anschuetz]

(Stewart Pinkerton) wrote in news:bjnmtj014u5
@enews3.newsguy.com:

> On 10 Sep 2003 15:47:47 GMT, Lou Anschuetz > wrote:
>
>>As someone with 25 years in IT, I have thrown away dozens
>>of supposedly competently designed SCSI/serial
>>cables that don't work. SCSI cables in particular are darn
>>hard to to get right for the newer higher speeds - and it
>>all seems to come down to how the cable(s) is insulated.
>>
>>I also agree that this doesn't necessarily have anything to do
>>with audio transmission. However, IMHO, this business about
>>insulation continues to bedevil me. Since it does play havoc
>>with digital signal transmission, it seems to me hard to leap
>>to an absolute conclusion that it has no effect in the analog
>>audio world. No hard science on this yet, but it is a very active
>>field of research...
>
> It's certainly *not* an active field of research for audio purposes.
> All that research was done many *decades* ago in the communications
> and measurement industries, and there are certainly significant
> effects at multi MegaHertz frequencies. Drop the frequency by a factor
> of a thousand, and you also drop the effects by a factor of a
> thousand........
>
> At audio frequencies, you will *never* measure artifacts in cables
> above -140dB referred to a 10 vrms signal, and usually much lower than
> that, right at the -160dB or so limit of the measuring gear.
While there may be no _audio_ research going on in this area, there is
other continuing research on insulation properties at low
frequencies.

At very low voltages, with frequencies just above the
audio range, this is certainly active work.

There are also known effects at 60hz, which is in the audio
range.

So, there are effects at very low voltages at reasonably low
frequencies and there are effects at higher voltages at audio
frequencies - I find it hard to simply assume that in the middle
of that curve there are absolutely no effects. I will certainly
grant that it might as easily not be the explanation for anything,
but there is reason to suspect...

As I started out, this may not be directly applicable, but there are
clear issues here that are not QED. I think it is unwise to
characterize all of materials science as old/completed science. I'm
willing to let the continuing efforts see if they show promise and
not just assume they won't.
--
Lou Anschuetz,
Network Manager, CMU, ECE Dept.

[chung]

Lou Anschuetz wrote:
> (Stewart Pinkerton) wrote in news:bjnmtj014u5
> @enews3.newsguy.com:

>>
>>
>> At audio frequencies, you will *never* measure artifacts in cables
>> above -140dB referred to a 10 vrms signal, and usually much lower than
>> that, right at the -160dB or so limit of the measuring gear.
> While there may be no _audio_ research going on in this area, there is
> other continuing research on insulation properties at low
> frequencies.
>
> At very low voltages, with frequencies just above the
> audio range, this is certainly active work.

Can you provide a little more detail on what research you are talking about?

>
> There are also known effects at 60hz, which is in the audio
> range.

Again, what effects are you talking about?

>
> So, there are effects at very low voltages at reasonably low
> frequencies and there are effects at higher voltages at audio
> frequencies - I find it hard to simply assume that in the middle
> of that curve there are absolutely no effects. I will certainly
> grant that it might as easily not be the explanation for anything,
> but there is reason to suspect...

What are those reasons?

>
> As I started out, this may not be directly applicable, but there are
> clear issues here that are not QED.

What are those clear issues that have to do with delivering audio
signals to speakers, or from one output to another input?

>I think it is unwise to
> characterize all of materials science as old/completed science.

Now you are making a straw man.

For speaker cables and interconnect cables, there is no new discovery,
or research to be done, in the last several decades, as far as I know.

>I'm
> willing to let the continuing efforts see if they show promise and
> not just assume they won't.

[Nousaine]

Lou Anschuetz wrote:

......large snips.......

>But, I also know that cables do sometimes act in funny ways. Until
>someone can adequately model every potential agent acting in random
>ways concurrently in a cable, there is room for some healthy
>scepticism about whether or not they make a difference.
>--
>Lou Anschuetz,
>Network Manager, CMU, ECE Dept.

Isn't it interestig that no manufacturer, seller, designer or enthusiast has
ever produced results from a bias controlled listening test that nominally
competent wires (rca, XLR or speaker cable) have any sound of there own.

I've conducted a half dozen experiments (ABX, Cable Swap) with more than 20
subjects over the years where cable differences, if present, should have been a
sonic factor (in 4 cases subjects used their reference systems and had verified
those "differences," one subject was the 'designer' of his regionally branded
cables and in total over half compared their own cables to another.

I think the lack of positive, replicable evidence is enough for everyone to be
skeptical about whether sonic cable differences exist.

[chung]

Lou Anschuetz wrote:
> chung > wrote in
> news:d6N7b.413447$uu5.75550@sccrnsc04:
>
>> Lou Anschuetz wrote:
>>> (Stewart Pinkerton) wrote in news:bjnmtj014u5
>>> @enews3.newsguy.com:
>>
>>>>
>>>>
>>>> At audio frequencies, you will *never* measure artifacts in cables
>>>> above -140dB referred to a 10 vrms signal, and usually much lower
>>>> than that, right at the -160dB or so limit of the measuring gear.
>>> While there may be no _audio_ research going on in this area, there
>>> is other continuing research on insulation properties at low
>>> frequencies.
>>>
>>> At very low voltages, with frequencies just above the
>>> audio range, this is certainly active work.
>>
>> Can you provide a little more detail on what research you are talking
>> about?
> Actually no. It would be unwise for me to comment on unpublished
> research.

Well, you were making it sound like it is research that is well known to
be ongoing. Is it active work only at your place of employment?

>>
>>>
>>> There are also known effects at 60hz, which is in the audio
>>> range.
>>
>> Again, what effects are you talking about?
>>
>>>
>>> So, there are effects at very low voltages at reasonably low
>>> frequencies and there are effects at higher voltages at audio
>>> frequencies - I find it hard to simply assume that in the middle
>>> of that curve there are absolutely no effects. I will certainly
>>> grant that it might as easily not be the explanation for anything,
>>> but there is reason to suspect...
>>
>> What are those reasons?
>>
>>>
>>> As I started out, this may not be directly applicable, but there are
>>> clear issues here that are not QED.
>>
>> What are those clear issues that have to do with delivering audio
>> signals to speakers, or from one output to another input?
> Quality, type of insulation (in regards to EFI, EMI, RFI, etc.
> etc.). Quality/type of connectors in regards to things as varying
> as insertion loss (fiber), crimped vs. soldered (turns out that
> crimping fiber cables may be better than glueing - interesing in
> that a lot of audio equipment manufacturers are alleging the same
> thing to be true with copper. Obviously different reasons/effects,
> but new information. This is not exhaustive, but just some
> an example.

But shielding issues are well understood and practically non-issues with
speaker cables. Of course, the fact we understand these things does not
prevent from someone incompetent to screw up the implementation, but you
can't say that our understanding is incomplete because someone screws up
the implementation.

What new informatin has come out about audio cables in the last 30
years? (We're not talking about fiber-optical cables here.)

>
> While nature is wonderful, it is also pretty consistent. To believe
> that the range 20-20,000 is somehow protected or asymptoted out of
> all effects is, IMHO, pretty bold.

No, it's just a range that is easily handled by cables, and it has been
handled successfully for decades. We're not talking about delivering
kilowatts of power or nano-amps of current here. Let's get practical.

> Yes, many individual effects can
> be said to be negligable - but with the complexity of a musical
> signal, there is the *potential* for multiple small effects to
> interact. I'm not trying to rule out Occam's Razor here, just pointing
> out that this stuff is not easy to model perfectly.

If such effects are not negligible, how come we still have not found
them, after using cables for decades? Do we need to model a cable
perfectly to one part in a trillion? Let's get practical. We are talking
about deliveriing audio, which is band-limited, at power levels that can
be comfortably handled.

>>
>>>I think it is unwise to
>>> characterize all of materials science as old/completed science.
>>
>> Now you are making a straw man.
> Not all all... See below
>>
>> For speaker cables and interconnect cables, there is no new discovery,
>> or research to be done, in the last several decades, as far as I know.
> As I noted above, there is no work specifically related to Audio that
> I know of. That doesn't establish that there is no link between
> what is happening research-wise and what happens with audio signals.
>
> Let's go back to Materials Science 101 for just a moment.With the
> exception of a perfect vacuum (which we don't have anywhere) there is
> no perfect insulator. All materials react in some way to
> electrical/magnetic fields. Fortunately, electricity mostly acts like
> water and doesn't "leak out" like alpha particles :) But, those
> insulators around wires do react. I'll certainly grant any day of
> the week that at low voltages and mostly small frequencies, those
> reactions may be *very* weak. However, with the complexity of a
> musical signal, the rules tested for single frequency, single voltage
> reactions *may* not apply in a linear way.

We have been looking for non-linear effects in cables at the current
levels required for audio reproduction for decades. We have not found
any limitation even at signal to noise ratios of 140 dB.

If you know that linearity in a cable is good down to the 140 dB level,
then you should feel confident that music, as a complex signal but made
up of sinusoids, should have no problem being transmitted faithfully.
You don't sweat the details about how complex music is, when it comes to
cables. Look at it another way, the non-linearities from the rest of the
chain are easiliy a million times worse. Which should you focus on?

> Not a lot of folks spend
> a lot of time looking at this (other than high-end cable makers) since
> there is, frankly, little value or profit. But, you'll also note that
> there is no uniform, best-of-breed, do-all, be-all cable construction
> for audio either.

No one said that. Mechanical reliability is important.

> This is the likely outcome of modeling when there
> are lots of parameters with potential multiple interactions.

You are needlessly complicating a straightforward situation. Do you
worry about how the indiviudals electrons behave in an amplifier?

>In fiber
> optics there is a "best of breed" for insulation, construction - though
> the crimp-on fiber connector is *new* (relatively) and the result of
> continuing research.

Fiber optics carry optical signals with Gigahertz's of modulation
bandwidth. Please have some appreciation for the scale of things.

>
> Most every cable user I know of (and I know a lot in both research
> and manufacturing) check every spool of wire that comes in. A lot of
> it doesn't pass master.

You mean "muster"? That's what they, the marketing guys, want you to
believe.

> Some does, but still doesn't work.

How does a piece of copper cable not work?
>I know of
> a certain large bulb manufacturer who tests all filament wire, but
> some that passes still doesn't work right.

Again, you have to appreciate the difference in scales. Filaments are
totally different, because they have to give light efficiently and last
a certain minimum of time. It is a very different application, and it is
not pure copper.

> It may be a slight
> difference microscopically, but it kills the unit. This is certainly
> an example of a well-known, well-engineered process that somehow
> still goes wrong.

There is no process that cannot be screwed up, although making a speaker
cable comes pretty close. The fact that the process goes wrong does not
necessarily mean that there is something esoteric going on.

>Engineering still has some room to grow to make
> those manufacturing processes work correctly every time. Hmmm, is it
> possible that some audio cable manufacturers don't check every spool
> and thus their general quality is lower - thus producing a "worse"
> sound? Good research question there.

I can't think of a less useful research question.

>
> All of us involved with music know that there are effects with every
> cable.

All? Are we talking about normal cables, like the ones they sell at
Radio Shack? Are we talking about effects like gauge size vs. current?

> For those of us doing live sound we try to use the best
> insulated (typically coax) cables we can to reduce stray effects.
> Any, every mixing console I've ever seen has a built in 80hz roll
> off control to eliminate breathing, as well as the occasional 60hz
> hum that is so prevalent.

Are there effects other than shielding that you have seen? You think
"breathing" is affected by the coax cable?

> We all know that that effect penetrates
> coax cables, which in theory should be mostly immune (and yes, I do
> know that this is most often the result of the electronics rather than
> the cabling).

No, we don't know that the "breathing" effect "penetrates" cables.

>
> Remember that I too hear no differences between competently designed
> interconnects and toslink cables. I do, however, contend that some
> speaker cables, for whatever reasons, do sound different.

Ehh, perception biases?

>I also know
> that testing such cables via human hearing is frought with difficulty.
> Some early, unpublished (and potentially invalid) research I did many
> decades ago as an undergraduate suggested that people couldn't
> even identify their own voice vs. someone else's (even of a different
> gender!) in some studies. That has the potential to be quite
> damming in certain areas of research, so might be quite hard to get
> funding for :) But it has always made me aware that testing by
> listening alone is not to be trusted - thus gives me pause when
> suggesting any kind of "audio" test of cables will be conclusive.
>
> But, I also know that cables do sometimes act in funny ways. Until
> someone can adequately model every potential agent acting in random
> ways concurrently in a cable, there is room for some healthy
> scepticism about whether or not they make a difference.

Please list those funny ways, and see if we can sort them out. I think
that makes for a much more productive discussion.

[Nousaine]

Lou Anschuetz wrote:

....snips to specific content .....

>
>chung > wrote in
et:
>
>>>> Can you provide a little more detail on what research you are
>>>> talking about?
>>> Actually no. It would be unwise for me to comment on unpublished
>>> research.

I wonder why you mentioned it then?

>> What new informatin has come out about audio cables in the last 30
>> years? (We're not talking about fiber-optical cables here.)
>I've already stated that little (if any) research is being done
>at sites other than cable companies on _audio_ cables. That doesn't
>mean that other things learned have no effect. This is a falsifiability
>issue.

There is no audibility 'research' being done at any high-end company. But
experiments that I've personally performed indicate that none is seemingly
necessary.

>>> While nature is wonderful, it is also pretty consistent. To believe
>>> that the range 20-20,000 is somehow protected or asymptoted out of
>>> all effects is, IMHO, pretty bold.
>>
>> No, it's just a range that is easily handled by cables, and it has
>> been handled successfully for decades. We're not talking about
>> delivering kilowatts of power or nano-amps of current here. Let's get
>> practical.

>For those same decades people have heard differences.

No they have only 'claimed' such. No interested party has ever produced a
bias-control listening test that nominally competent audio interconnects and
speaker cables have any sound of their own.

You argue it
>is bias (which it *may* be), but there may be other explanations
>as well.

Such as?

>>> Most every cable user I know of (and I know a lot in both research
>>> and manufacturing) check every spool of wire that comes in. A lot of
>>> it doesn't pass master.

In what ways. I once had a job as a sheey metal expediter and we tested every
coil that came in. Some were rejected but mostly because it was the wrong size
or the spool wouldn't fit on the decoiler (one time because it was stamped in
ink "ford reject" although there was nothing else wrong with the steel.)

>>> Remember that I too hear no differences between competently designed
>>> interconnects and toslink cables. I do, however, contend that some
>>> speaker cables, for whatever reasons, do sound different.
>>
>> Ehh, perception biases?
>It is one of the possibilities, yes. I just don't happen to think it
>is the only one. Hence my relating the story below.

There has been no experimental listening test results that indicate otherwise.
I suppose that on occasion that the interface 'boxes' might produce an effect
but IME I've not found this to be the case.

>>>I also know
>>> that testing such cables via human hearing is frought with
>>> difficulty. Some early, unpublished (and potentially invalid)
>>> research I did many decades ago as an undergraduate suggested that
>>> people couldn't even identify their own voice vs. someone else's
>>> (even of a different gender!) in some studies. That has the potential
>>> to be quite damming in certain areas of research, so might be quite
>>> hard to get funding for :) But it has always made me aware that
>>> testing by listening alone is not to be trusted - thus gives me pause
>>> when suggesting any kind of "audio" test of cables will be
>>> conclusive.

So if you can't 'hear' the effect, why bother? No one argues that measurements
made at the microscopic level can always find variations that are not visible
with the naked eye (or audible with the naked ear) so why would we care?

>>>
>>> But, I also know that cables do sometimes act in funny ways. Until
>>> someone can adequately model every potential agent acting in random
>>> ways concurrently in a cable, there is room for some healthy
>>> scepticism about whether or not they make a difference.

Even if they do operate in funny ways unless it affects the sound quality the
effects are nearly always noise or loss of transmission, which means a system
error of some type. Those circumstances, which you describe below, need fixing
but have nobearing on the innate sound quality of the transmission media.

Here's mu 'funny wire' story. When making soem speaker measurements my computer
based test gear kept giving me an error message indicting that I might have had
a wire failure. Sure enough substituting a different cable seemed to fix the
problem although that cable tested good for conductivity.

Next time around I got the same message; and hunted the problem down to
re-seating the ISA card in the computer.

Another time, long ago, I had an intermittent channel drop-out problem that
would fix itself whenever I touched any piece of equipment in the rack. Turned
out to be a tone arm lead wire that was broken behind the rca plug and would
operate only intermittently.

Neither of those conditions had any bearing on the sound quality of the wires.
The lesson I learned from the latter is not to expect high-end wire to be
reliable.

>>
>> Please list those funny ways, and see if we can sort them out. I think
>> that makes for a much more productive discussion.
>Not sure how that helps unless you follow me around :)
>
>Example: take two new snake (bundle cables) out on stage. Check each
>one for all normal effects. Thirty minutes into the show one connector
>starts picking up a flourescent light. The rest of the individual
>coax's don't. Declare this one bad. Accidentally use the same coax in
>the same bundle the next night - works fine.
>
>Example, hook up my television camera to a snake bundle with multiple
>analog coax feeds. An hour into shooting the remote monitors show
>ghosting (known as cable reflections). Change to other coax. After shoot
>put back the first one - no problem. Jump up and down on cable, twist
>it, scream at it, etc. It never fails again. Cosmic particles? Pixie
>dust? don't know - flaw is never found again. Happened to me last month.
>Cable tests perfectly (as do the electronics).

But you're not talking about home audio grade wires or conditions here. And
even if so; what does operating faults like this have to do with the 'sound' of
tranmission media?

>I *never* assume that cables will act as theory says. 1/20 or so times
>they stop acting normally. Many times we find a flaw, many times we
>don't. All the video/audio guys I know
>bring lots of extra cabling. Sure, many of the failures
>are going to be mechanical. Sometimes they aren't.
>
>I'm pretty sure that the failures I've just documented aren't
>perceptual bias :) Since we also can't establish mechanical
>issues, there is clearly something else going on. Either it is
>just magic, or the cables are being affected by *something* in the
>environment.

I'm thinking the examples you used were probably all mechanically related.

If those cables, made for professional use, can exhibit
>non-easily explained behaviors, I find it hard to believe that
>speaker cables don't as well. I'm not attempting to *prove*
>anything - just provide a rationale for why I remain sceptical
>about cables all sounding the same. I wish they did to me too ;)

So YOU hear speaker cables? Why not take a cable with 'sound' and compare it to
zip cord in a bias controlled listening test and tell us what you find?

[Stewart Pinkerton]

On 11 Sep 2003 15:25:29 GMT, Lou Anschuetz > wrote:

>chung > wrote in
>news:d6N7b.413447$uu5.75550@sccrnsc04:
>
>> Lou Anschuetz wrote:
>>> (Stewart Pinkerton) wrote in news:bjnmtj014u5
>>> @enews3.newsguy.com:
>>
>>>>
>>>>
>>>> At audio frequencies, you will *never* measure artifacts in cables
>>>> above -140dB referred to a 10 vrms signal, and usually much lower
>>>> than that, right at the -160dB or so limit of the measuring gear.
>>> While there may be no _audio_ research going on in this area, there
>>> is other continuing research on insulation properties at low
>>> frequencies.
>>>
>>> At very low voltages, with frequencies just above the
>>> audio range, this is certainly active work.
>>
>> Can you provide a little more detail on what research you are talking
>> about?

>Actually no. It would be unwise for me to comment on unpublished
>research.

Hmmmmmmmm. Didn't stop you commenting on it previously......

>While nature is wonderful, it is also pretty consistent. To believe
>that the range 20-20,000 is somehow protected or asymptoted out of
>all effects is, IMHO, pretty bold.

No one suggested that *low* frequencies were exempt, simply that
effects which occur at tens or hundreds of MegaHertz have little or no
relevance to things that happen below 20kHz. Can you show *any* AC
effects below 100Hz?

> Yes, many individual effects can
>be said to be negligable - but with the complexity of a musical
>signal, there is the *potential* for multiple small effects to
>interact. I'm not trying to rule out Occam's Razor here, just pointing
>out that this stuff is not easy to model perfectly.

It is in fact *trivially* easy to model at low frequencies, and
absolutely *no* effects can be shown above -160dB at low frequencies.

>Let's go back to Materials Science 101 for just a moment.With the
>exception of a perfect vacuum (which we don't have anywhere) there is
>no perfect insulator. All materials react in some way to
>electrical/magnetic fields. Fortunately, electricity mostly acts like
>water and doesn't "leak out" like alpha particles :) But, those
>insulators around wires do react. I'll certainly grant any day of
>the week that at low voltages and mostly small frequencies, those
>reactions may be *very* weak.

Indeed so - see above.

> However, with the complexity of a
>musical signal, the rules tested for single frequency, single voltage
>reactions *may* not apply in a linear way.

Excuse me? Musical signals are not in fact particularly complex, and
*no* non-linearies have been noted anywhere near audible levels. See
above.

>Not a lot of folks spend
>a lot of time looking at this (other than high-end cable makers) since
>there is, frankly, little value or profit.

Indeed so, probably similar to the number of people who investigate
the possibility of the Moon being made from green cheese.

> But, you'll also note that
>there is no uniform, best-of-breed, do-all, be-all cable construction
>for audio either.

Well of course there isn't - because *it makes no difference*.

> This is the likely outcome of modeling when there
>are lots of parameters with potential multiple interactions.

No, it's the likely outcome of the desperate scrabble for difference
to provide a Unique Selling Point among cables which *all* sound
identical.

> In fiber
>optics there is a "best of breed" for insulation, construction - though
>the crimp-on fiber connector is *new* (relatively) and the result of
>continuing research.

Unfortunately, the 'best of breed', which is the monomode quartz
fibre, is not sold by high end audio companies, only professional
communications companies - who have been selling it for *decades* at
prices well below those asked by so-called 'high-end' audio companies
for vastly inferior products. Also, the termination of such fibres is
a matter of precision engineering, not 'crimping'.

>All of us involved with music know that there are effects with every
>cable.

All of us who have tried level-matched blind comparisons know that
there is *no* audible difference. Have you ever wondered *why*, when a
pool of around $4,000 has lain on the table for more than five years,
no one has ever even *tried* to collect it by differentiating two
cables?

>But it has always made me aware that testing by
>listening alone is not to be trusted - thus gives me pause when
>suggesting any kind of "audio" test of cables will be conclusive.

Oh right, so cable differences are not audible, but still matter in
music reproduction systems? :-)
--

Stewart Pinkerton | Music is Art - Audio is Engineering

[Stewart Pinkerton]

On Thu, 11 Sep 2003 20:15:50 GMT, Lou Anschuetz >
wrote:

>chung > wrote in
et:
>
>>>> Can you provide a little more detail on what research you are
>>>> talking about?
>>> Actually no. It would be unwise for me to comment on unpublished
>>> research.
>>
>> Well, you were making it sound like it is research that is well known
>> to be ongoing. Is it active work only at your place of employment?
>Lots of places as it turns out. But none I can feel free to
>disclose. Research dollars come from many places :)

Oh please! Don't be coy - I worked in military electronics for about
twenty years, doing work at audio frequencies that was *thousands* of
times more sensitive than domestic audio, and *no* effects due to
cabling were *ever* noted, aside from simple microphony.

>For centuries people were quite happy to believe the sun
>rotates around the earth - and they did the necessary math.

No, they didn't. Those people who did the necessary math realised that
this was not the case. Of course, the 'true believers' persecuted them
without mercy. Remind you of any modern parallel? :-)

>Example, hook up my television camera to a snake bundle with multiple
>analog coax feeds. An hour into shooting the remote monitors show
>ghosting (known as cable reflections). Change to other coax. After shoot
>put back the first one - no problem. Jump up and down on cable, twist
>it, scream at it, etc. It never fails again. Cosmic particles? Pixie
>dust? don't know - flaw is never found again. Happened to me last month.
>Cable tests perfectly (as do the electronics).

Oh please! This is just a poor connection.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

[ludovic mirabel]

(Nousaine) wrote in message >...
(See remainder of the discussion below:)
>
> So YOU hear speaker cables? Why not take a cable with 'sound' and compare it to
> zip cord in a bias controlled listening test and tell us what you find?

Why not? Because why should one bother with a $ 600:00 switch
and trained assistants if the result is predictable? You'll hear "no
difference" just like the 80% or more of the listeners in ALL the
reported "bias controlled" listening tests, whatever is being tested:
cables, preamps, amps, cd players, dacs, distortion under
2%-everything. And if you score within the "yes" 20% group you'll be
told that the goal is now moved and the criteria for the likes of YOU
are now set higher.
For the record- it was not I , who inroduced the topic of "bias
controlled" tests. Unless you meant something else -not ABX. Did you?
Ludovic Mirabel

> Lou Anschuetz wrote:
>
> ...snips to specific content .....
>
> >
> >chung > wrote in
> et:
> >
> >>>> Can you provide a little more detail on what research you are
> >>>> talking about?
> >>> Actually no. It would be unwise for me to comment on unpublished
> >>> research.
>
> I wonder why you mentioned it then?
>
> >> What new informatin has come out about audio cables in the last 30
> >> years? (We're not talking about fiber-optical cables here.)
> >I've already stated that little (if any) research is being done
> >at sites other than cable companies on _audio_ cables. That doesn't
> >mean that other things learned have no effect. This is a falsifiability
> >issue.
>
> There is no audibility 'research' being done at any high-end company. But
> experiments that I've personally performed indicate that none is seemingly
> necessary.
>
> >>> While nature is wonderful, it is also pretty consistent. To believe
> >>> that the range 20-20,000 is somehow protected or asymptoted out of
> >>> all effects is, IMHO, pretty bold.
> >>
> >> No, it's just a range that is easily handled by cables, and it has
> >> been handled successfully for decades. We're not talking about
> >> delivering kilowatts of power or nano-amps of current here. Let's get
> >> practical.
>
> >For those same decades people have heard differences.
>
> No they have only 'claimed' such. No interested party has ever produced a
> bias-control listening test that nominally competent audio interconnects and
> speaker cables have any sound of their own.
>
> You argue it
> >is bias (which it *may* be), but there may be other explanations
> >as well.
>
> Such as?
>
> >>> Most every cable user I know of (and I know a lot in both research
> >>> and manufacturing) check every spool of wire that comes in. A lot of
> >>> it doesn't pass master.
>
> In what ways. I once had a job as a sheey metal expediter and we tested every
> coil that came in. Some were rejected but mostly because it was the wrong size
> or the spool wouldn't fit on the decoiler (one time because it was stamped in
> ink "ford reject" although there was nothing else wrong with the steel.)
>
> >>> Remember that I too hear no differences between competently designed
> >>> interconnects and toslink cables. I do, however, contend that some
> >>> speaker cables, for whatever reasons, do sound different.
> >>
> >> Ehh, perception biases?
> >It is one of the possibilities, yes. I just don't happen to think it
> >is the only one. Hence my relating the story below.
>
> There has been no experimental listening test results that indicate otherwise.
> I suppose that on occasion that the interface 'boxes' might produce an effect
> but IME I've not found this to be the case.
>
> >>>I also know
> >>> that testing such cables via human hearing is frought with
> >>> difficulty. Some early, unpublished (and potentially invalid)
> >>> research I did many decades ago as an undergraduate suggested that
> >>> people couldn't even identify their own voice vs. someone else's
> >>> (even of a different gender!) in some studies. That has the potential
> >>> to be quite damming in certain areas of research, so might be quite
> >>> hard to get funding for :) But it has always made me aware that
> >>> testing by listening alone is not to be trusted - thus gives me pause
> >>> when suggesting any kind of "audio" test of cables will be
> >>> conclusive.
>
> So if you can't 'hear' the effect, why bother? No one argues that measurements
> made at the microscopic level can always find variations that are not visible
> with the naked eye (or audible with the naked ear) so why would we care?
>
> >>>
> >>> But, I also know that cables do sometimes act in funny ways. Until
> >>> someone can adequately model every potential agent acting in random
> >>> ways concurrently in a cable, there is room for some healthy
> >>> scepticism about whether or not they make a difference.
>
> Even if they do operate in funny ways unless it affects the sound quality the
> effects are nearly always noise or loss of transmission, which means a system
> error of some type. Those circumstances, which you describe below, need fixing
> but have nobearing on the innate sound quality of the transmission media.
>
> Here's mu 'funny wire' story. When making soem speaker measurements my computer
> based test gear kept giving me an error message indicting that I might have had
> a wire failure. Sure enough substituting a different cable seemed to fix the
> problem although that cable tested good for conductivity.
>
> Next time around I got the same message; and hunted the problem down to
> re-seating the ISA card in the computer.
>
> Another time, long ago, I had an intermittent channel drop-out problem that
> would fix itself whenever I touched any piece of equipment in the rack. Turned
> out to be a tone arm lead wire that was broken behind the rca plug and would
> operate only intermittently.
>
> Neither of those conditions had any bearing on the sound quality of the wires.
> The lesson I learned from the latter is not to expect high-end wire to be
> reliable.
>
> >>
> >> Please list those funny ways, and see if we can sort them out. I think
> >> that makes for a much more productive discussion.
> >Not sure how that helps unless you follow me around :)
> >
> >Example: take two new snake (bundle cables) out on stage. Check each
> >one for all normal effects. Thirty minutes into the show one connector
> >starts picking up a flourescent light. The rest of the individual
> >coax's don't. Declare this one bad. Accidentally use the same coax in
> >the same bundle the next night - works fine.
> >
> >Example, hook up my television camera to a snake bundle with multiple
> >analog coax feeds. An hour into shooting the remote monitors show
> >ghosting (known as cable reflections). Change to other coax. After shoot
> >put back the first one - no problem. Jump up and down on cable, twist
> >it, scream at it, etc. It never fails again. Cosmic particles? Pixie
> >dust? don't know - flaw is never found again. Happened to me last month.
> >Cable tests perfectly (as do the electronics).
>
> But you're not talking about home audio grade wires or conditions here. And
> even if so; what does operating faults like this have to do with the 'sound' of
> tranmission media?
>
> >I *never* assume that cables will act as theory says. 1/20 or so times
> >they stop acting normally. Many times we find a flaw, many times we
> >don't. All the video/audio guys I know
> >bring lots of extra cabling. Sure, many of the failures
> >are going to be mechanical. Sometimes they aren't.
> >
> >I'm pretty sure that the failures I've just documented aren't
> >perceptual bias :) Since we also can't establish mechanical
> >issues, there is clearly something else going on. Either it is
> >just magic, or the cables are being affected by *something* in the
> >environment.
>
> I'm thinking the examples you used were probably all mechanically related.
>
> If those cables, made for professional use, can exhibit
> >non-easily explained behaviors, I find it hard to believe that
> >speaker cables don't as well. I'm not attempting to *prove*
> >anything - just provide a rationale for why I remain sceptical
> >about cables all sounding the same. I wish they did to me too ;)

[ShLampen]

In article >, (Richard D
Pierce) writes:

>Second, even considering the speaker as an independent source of
>noise, consider the Thevenin equivalent of its source generator
>with respect to the effective load, i.e., the amplifier output,
>where that source impedance is a half dozen ohms, and the load
>is a small fraction of an Ohm.

All the data on amplifiers show very low output impedance, on the order of
milliohms. Isn;t this necessary to produce the current required without
unecessary loading at the source (slew rate?). Speaker impedances do vary, but
it's pretty rare that they go below 2 ohms, isn't it? I always learned that,
if the load was at least ten time the impedance of the source (which would be
the case if you believe my numbers) then, at audio frequencies, you can ignore
the load impedance as a factor. Agree?

Steve Lampen
Belden Electronics Division
in the Hong Kong airport getting bored

[ShLampen]

In article >, Lou Anschuetz >
writes:

>OTOH, I can understand how he comes to the conclusions he
>comes to. As someone with 25 years in IT, I have thrown away dozens
>of supposedly competently designed SCSI/serial
>cables that don't work. SCSI cables in particular are darn
>hard to to get right for the newer higher speeds - and it
>all seems to come down to how the cable(s) is insulated.
>
>I also agree that this doesn't necessarily have anything to do
>with audio transmission. However, IMHO, this business about
>insulation continues to bedevil me. Since it does play havoc
>with digital signal transmission, it seems to me hard to leap
>to an absolute conclusion that it has no effect in the analog
>audio world. No hard science on this yet, but it is a very active
>field of research...

Well, I'm on a plane flying from Beijing to Hong Kong (and on to Melbourne,
Australia) listening to Chinese Pop music in my headphones, and nothing to do,
so I thought I would just jump in here!

Why do some cables work on signal X but not with signal Y? The answer is
simple: wavelength. (The answer is simple, the explanation is a little more
complicated.) Every signal, data, audio, video, etc, etc. occupies one or more
frequencies. Each frequency has a wavelength, that is, there is an
electromagnetic wave moving down the cable that has a specific length. This
can be calculated by dividing 300,000,000 by that frequency. (The answer comes
out in meters, so us backwards USA types have to multiply by 3.28 to get to
feet.)

If you look at 20 kHz (or you can pick any frequency you want), that gives you
a wavelength of 15,000 meters (about 9 miles). What that means is that the
impedance of the cable (how it reacts to frequencies) is of no consequence.
Most engineers agree that the ACTUAL critical distance is 1/4 wavelength which
is, in this case 2.25 miles, still too far to have any effect. This distance is
also affect by the plastic around the conductors. This affects the speed
"velocity" of the signal. (Signals only move at the speed of light in a vaccum,
i.e. outer space. If you ever have a chance to check out your speakers there,
be sure and give me a complete test report!)

Let's say your interconnect cables were the worst ever made (a "velocity of
propagation" of 50%). You would multiply the wavelength by 50% so we're down
to 1.12 miles. Anybody with one mile speaker cables? data cable? mic cables?
video cables? audio cable? Well, yes, there are people with AUDIO cables of
that length or more. They call themselves the TELEPHONE COMPANY. And the
maximum distance between your home and your central office is 13,000 ft. (over
2 miles).

But the twisted pairs they use (even fancy new ones, Category 3) are not the
correct impedance (too expensive). Luckily, the audio on your phone ends at
3500 Hz. You can calculate the bandwidth and see you can go VERY far before
you need to have impedance-specific twisted pairs. I'll be honest and tell you
that I don't know the actual occupied bandwidth of a 56k data signal. (I think
it's NRZI Manchester Coded, that would make it 28kHz bandwidth.) I'm sure you
note that this puts it on the edge for performance if you are far from the
central office, and you can't always get dialup that fast. And you'll
understand why in the USA, the FCC now mandates that all telephone wiring must
be Category 3 or better. Category 3 is impedance-specific (100 ohms) data
cable. But there are other reasons the FCC made this a standard besides
distance. The signals either go back to the source or simply stop in the cable
(called "standing waves") and then radiate all that reflected energegy into
cables around them. That's why the phone company is trying to use data cable,
to avoid "alien crosstalk" (between cables).

That's why you can use crappy interconnect cables that come free with your
receiver and it all sounds pretty good. They aren't long enough to make a
difference. As long as you have continuity (electrical signal flow), you'll be
just fine. But what if you use that cable for DIGITAL (i.e. S/PDIF). Suddenly
we're sampling that audio at 44.1kHz (like a CD), and the bandwidth is defined
as 128 times the sampling (5.6448 MHz, if memory serves). Let's just use 6 MHz
to make it easy. (If you don't want easy, do it yourself.)

300,000,000 divided by 6,000,000 = 50 meters. 1/4-wavelength = 12.5 meters or
about 44 feet. How long is your cable? 3 ft? 6 ft? No problem. It's still
not LONG enough to make a difference. Now, if you want to send S/PDIF to the
other end of the house, that might be 40 ft. or even more. What would you do?
Be sure and use cable which is the correct impedance. S/PDIF requires 75 ohm
cable (75 ohm cable has the lowest signal loss "attenuation" so it is used for
many applications where low loss is required).

What if you get a really long piece of crappy cable? What impedance is it?
Who knows!! And what will happen is that the signal, which will require a 75
ohm "transmission line" and not see it. The farther it is away from 75 ohm the
more the signal will be REFLECTED back to the source and not get to the other
end. This is called "return loss" in the cable world. You send me the actual
impedance of your cable and I can calculate the mismatch and the return loss.

But, if you get the right 75 ohm cable, how far can you go? It depends on the
size of the wire (gage) in the middle. Let's assume it is a 20 AWG center
(such as Belden 1505A, the world's most popular coax cable and a nice generic
size).. Then the cable could go 716 ft. (This is based on a source voltage of
0.5v and a minimum received voltage of 0.2v, at a bandwidth of 5.6448 MHz.)
Yup, 700 feet!!! (Snippy aside: try going 700 ft. on a piece of toslink
plastic fiber!)

And in the digital format, you can be real close to the maximum and the signal
(i.e. data/audio) sounds just perfect. But add in one patch cord, or one less
than perfect connector, or just a few more feet of cable, and you could be down
the slippery slope of the "digital cliff". So, how many of you have to run 700
ft.??? Not many, I assume.

This is not to say you shouldn't have cable with low capacitance. Digital
signals need low capacitance to keep their sharp edges (i.e. the clock). But
(amazing fact that no cable manufacturer ever told you) once you choose the
construction (i.e. plastic/dielectric/velocity) and the impedance (i.e. 75
ohms) the capacitance is AUTOMATIC. High velocity foam coax 75 ohm = 15 pF/ft.
Old solid polyethylene 75 ohm coax = 20 pF/ft. And this is why you should
avoid CATV coax, because it's not all copper in that center conductor (it's
copper-clad steel for high-frequency-only applications where only the skin of
the conductor is working.) This means the resistance is 5 to 7 times higher
than an all-copper center and the distance you can go is 5 to 7 times shorter.
(OK, we're down to 100 ft. and you're going 6 ft., but I wouldn't use it.)

And all those SCSI cables (at the beginning of this thread) suffer from the
same problem. Most of them use generic multiconductors (just pull one apart if
you don't believe me). The impedance of a pair of wires is determined by their
size (gage), the distance between them and the quality (dielectric contact) of
the material inbetween. So, while the plastic is important, these cables fail
at high frequencies because of the DISTANCE between conductors, which varies
all over the place. Open up a SCSI 2 or 3 cable, what do you see? Ahhhh,
twisted pairs!!! And the better the pairs (tighter impedance specs) the less
the mismatch, the less the return loss, the greater the received signal
strength, the less the bit errors. Flat cable can also help maintain impedance
specs, at least better than just a bunch of loose wires.

As frequencies go higher and higher, every dimension becomes more critical.
Just take your car on a racetrack if you don't believe me. You need a race car?
Buy a race car! You need a high-frequency cable? Buy one made, tested,
verified, and guaranteed for whatever frequency band you wish.

OK, class, how did I do?

Steve Lampen
Belden Electronics Division

[Lou Anschuetz]

Mark Wilkinson > wrote in
news:wTt9b.467714$o%2.207687@sccrnsc02:

> In article <ivn9b.463174$Ho3.74971@sccrnsc03>, Lou Anschuetz says...
>>
(Nousaine) wrote in
et:
>>
>>> Lou Anschuetz wrote:
>>>
>>> ...snips to specific content .....
>>> So YOU hear speaker cables? Why not take a cable with 'sound' and
>>> compare it to zip cord in a bias controlled listening test and tell
>>> us what you find?
>>Let me relate one extreme example. I used to use zip cord on my
>>speakers (McCormack DNA 1 Deluxe to Apogee Slant 6). They sounded
>>"OK." On the advice of many folks I purchased some moderately
>>priced real speaker cables of the same length (and same gauge
>>as it turns out). It turned out that with 2 different SPL
>>meters there was a *measureable* difference. With the zip cord
>>sound was down 6 dB below 50hz compared to high-end cable.
>>I can reproduce this at will.
>>
>
> Sorry, this just plain isn't possible -- unless you are telling me
> the "high-end cable" had a 6db attenuating high shelving filter,
> hinged somewhere around 50hz, built into it. I can't believe anyone
> would build such a gimmick. Please give more more info as to how you
> tested.
>
Once again - I agree with you in principle. (I try to only
cite weird examples since all others are dismissed :)

Zip cord - same length as named-cable, same gauge as named-cable.

Put on zip cord, walk down the frequencies with a test CD
(the Stereophile works fine here). Using either A fast or
C slow, see what (relative) dB ratings you see. This is *not*
a cliff effect of course, but a gradual curve.

As you lower the frequency, the dB ratings stay higher with the
named cable (in both A & C, but varying in amounts).

Test again as this cannot be possible (I agree). Same thing.

I'm not so foolish as to believe there is something other
worldly going on - but there is some reactance to the stranded
zip cable (now serving duty quite nicely as extension cords :)

Maybe it's a flaw in the zip cords (my preferred explanation
actually) but the effect happens.

This absolutely comes back to what I've said repeatedly, there
is a "house" sound to speaker cables that is probably not due to
some magic engineering, but either some flawed engineering or
some error in manufacturing that is common from various cabling
supply house. I tend to think such flaws more often than not
are in material content and/or insulation properties. Certainly
the named cable used twisting, while the zip cord does not.
Maybe there is some EMI, RFI, EFI effect in my house that is
undiagnosed. I'm told by many that these things should not
effect the sound, but in this case something is clearly
affecting the performance (even if not the sound). In my
case maybe I'm just lucky to have picked a twisted pair
speaker cable that happens to eliminate some effect. But,
there is a reason why speaker cable folks do research (even
if some of it results in bizarre unlikely explanations :)

I'm betting though that such effects - even when much smaller -
occur during testing and some design is implemented that by
good fortune fixes the flaw. The problem is that we are looking
to explain things when each individual item is small and out
at an asymptote. Sales guys then jump in and latch on to some
theoretical, if unlikely, explanation instead of letting the
company admit that they found it by accident and folks seem
to like it :) But, being unable to explain it doesn't mean
it is unexplicable - just sometimes difficult to explain.

I'm willing to go through life allowing for things I don't
understand - but am willing to learn about.
--
Lou Anschuetz,
Network Manager, CMU, ECE Dept.

[[email protected]]

>It turned out that with 2 different SPL
>meters there was a *measureable* difference. With the zip cord
>sound was down 6 dB below 50hz compared to high-end cable.
>I can reproduce this at will.

This indicates a serious problem in either the measurement procedure
or in your system somewhere. I'd suggest you spend some time looking
for what the problem really is, rather than drawing conclusions that
a cable change could cause it. I'd start by looking for something that
moved in the room, causing the bass standing waves at your SPL meter
to be different. Even not having your body in the same place for
both measurements might do it. Or, what about a really bad connection
in one of your cables, such as having only a couple of strands connected
to do all the work - maybe you really compared a 12ga cable against
a 28ga one :-)

Try measuring the voltage at the speaker terminals for each wire.
Does that show a severe difference? If not, the problem must be an
acoustic one. If so, look for a very bad connection or a very
unstable amplifier.

Bob

[Nousaine]

Lou Anschuetz wrote:

>Mark Wilkinson > wrote in
>news:wTt9b.467714$o%2.207687@sccrnsc02:
>
>> In article <ivn9b.463174$Ho3.74971@sccrnsc03>, Lou Anschuetz says...
>>>
(Nousaine) wrote in
et:
>>>
>>>> Lou Anschuetz wrote:
>>>>
>>>> ...snips to specific content .....
>>>> So YOU hear speaker cables? Why not take a cable with 'sound' and
>>>> compare it to zip cord in a bias controlled listening test and tell
>>>> us what you find?

>>Let me relate one extreme example. I used to use zip cord on my
>>>speakers (McCormack DNA 1 Deluxe to Apogee Slant 6). They sounded
>>>"OK."

And......

On the advice of many folks I purchased some moderately
>>>priced real speaker cables of the same length (and same gauge
>>>as it turns out). It turned out that with 2 different SPL
>>>meters there was a *measureable* difference.

"Real" speaker cable you say? What was 'unreal' about your original cable?

With the zip cord
>>>sound was down 6 dB below 50hz compared to high-end cable.
>>>I can reproduce this at will.

OK; how about the conditions under which you 'took' the measurements?

>> Sorry, this just plain isn't possible -- unless you are telling me
>> the "high-end cable" had a 6db attenuating high shelving filter,
>> hinged somewhere around 50hz, built into it. I can't believe anyone
>> would build such a gimmick. Please give more more info as to how you
>> tested.
>>
>Once again - I agree with you in principle. (I try to only
>cite weird examples since all others are dismissed :)

What 'all others' have been dismissed?


>
>Zip cord - same length as named-cable, same gauge as named-cable.
>
>Put on zip cord, walk down the frequencies with a test CD
>(the Stereophile works fine here). Using either A fast or
>C slow, see what (relative) dB ratings you see. This is *not*
>a cliff effect of course, but a gradual curve.

Tell us more; why not describe the full experimental conditions?


>As you lower the frequency, the dB ratings stay higher with the
>named cable (in both A & C, but varying in amounts).
>
>Test again as this cannot be possible (I agree). Same thing.
>
>I'm not so foolish as to believe there is something other
>worldly going on - but there is some reactance to the stranded
>zip cable (now serving duty quite nicely as extension cords :)
>
>Maybe it's a flaw in the zip cords (my preferred explanation
>actually) but the effect happens.

It does? Why haven't others reported it?

>This absolutely comes back to what I've said repeatedly, there
>is a "house" sound to speaker cables that is probably not due to
>some magic engineering, but either some flawed engineering or
>some error in manufacturing that is common from various cabling
>supply house.

Well what might be the 'cause?' That no supply house has been able to document?


I tend to think such flaws more often than not
>are in material content and/or insulation properties. Certainly
>the named cable used twisting, while the zip cord does not.

And you have no evidence except that you "tend to think" that "such flaws" are
even extant? Now we're getting down to brass tacks.


>Maybe there is some EMI, RFI, EFI effect in my house that is
>undiagnosed. I'm told by many that these things should not
>effect the sound, but in this case something is clearly
>affecting the performance (even if not the sound). In my
>case maybe I'm just lucky to have picked a twisted pair
>speaker cable that happens to eliminate some effect.

Eliminate "what" effect?

But,
>there is a reason why speaker cable folks do research (even
>if some of it results in bizarre unlikely explanations :)

There is no evidence that 'speaker cable folks' do any research. Please give me
a link to any true listening research published by cable manufacturers.


>
>I'm betting though that such effects - even when much smaller -
>occur during testing and some design is implemented that by
>good fortune fixes the flaw.

What "flaw?"

The problem is that we are looking
>to explain things when each individual item is small and out
>at an asymptote. Sales guys then jump in and latch on to some
>theoretical, if unlikely, explanation instead of letting the
>company admit that they found it by accident and folks seem
>to like it :)

Please;

But, being unable to explain it doesn't mean
>it is unexplicable - just sometimes difficult to explain.

Or replicate under bias controlled conditions ....wouldn't you say?


>
>I'm willing to go through life allowing for things I don't
>understand - but am willing to learn about.
>--
>Lou Anschuetz,
>Network Manager, CMU, ECE Dept.

OK; but how much listening under bias-controlled conditions have you
experienced?

[Mark Wilkinson]

Lou Anschuetz > wrote in message news:<v7J9b.474021$YN5.323102@sccrnsc01>...
> Mark Wilkinson > wrote in
> news:wTt9b.467714$o%2.207687@sccrnsc02:
>
> > In article <ivn9b.463174$Ho3.74971@sccrnsc03>, Lou Anschuetz says...
> >>
> (Nousaine) wrote in
> et:
> >>
> >>> Lou Anschuetz wrote:
> >>>
> >>> ...snips to specific content .....
> >>> So YOU hear speaker cables? Why not take a cable with 'sound' and
> >>> compare it to zip cord in a bias controlled listening test and tell
> >>> us what you find?
> >>Let me relate one extreme example. I used to use zip cord on my
> >>speakers (McCormack DNA 1 Deluxe to Apogee Slant 6). They sounded
> >>"OK." On the advice of many folks I purchased some moderately
> >>priced real speaker cables of the same length (and same gauge
> >>as it turns out). It turned out that with 2 different SPL
> >>meters there was a *measureable* difference. With the zip cord
> >>sound was down 6 dB below 50hz compared to high-end cable.
> >>I can reproduce this at will.
> >>
> >
> > Sorry, this just plain isn't possible -- unless you are telling me
> > the "high-end cable" had a 6db attenuating high shelving filter,
> > hinged somewhere around 50hz, built into it. I can't believe anyone
> > would build such a gimmick. Please give more more info as to how you
> > tested.
> >
> Once again - I agree with you in principle. (I try to only
> cite weird examples since all others are dismissed :)
>
> Zip cord - same length as named-cable, same gauge as named-cable.
>
> Put on zip cord, walk down the frequencies with a test CD
> (the Stereophile works fine here). Using either A fast or
> C slow, see what (relative) dB ratings you see. This is *not*
> a cliff effect of course, but a gradual curve.
>
> As you lower the frequency, the dB ratings stay higher with the
> named cable (in both A & C, but varying in amounts).
>
> Test again as this cannot be possible (I agree). Same thing.
>
> I'm not so foolish as to believe there is something other
> worldly going on - but there is some reactance to the stranded
> zip cable (now serving duty quite nicely as extension cords :)
>
> Maybe it's a flaw in the zip cords (my preferred explanation
> actually) but the effect happens.
>
> This absolutely comes back to what I've said repeatedly, there
> is a "house" sound to speaker cables that is probably not due to
> some magic engineering, but either some flawed engineering or
> some error in manufacturing that is common from various cabling
> supply house. I tend to think such flaws more often than not
> are in material content and/or insulation properties. Certainly
> the named cable used twisting, while the zip cord does not.
> Maybe there is some EMI, RFI, EFI effect in my house that is
> undiagnosed. I'm told by many that these things should not
> effect the sound, but in this case something is clearly
> affecting the performance (even if not the sound). In my
> case maybe I'm just lucky to have picked a twisted pair
> speaker cable that happens to eliminate some effect. But,
> there is a reason why speaker cable folks do research (even
> if some of it results in bizarre unlikely explanations :)
>
> I'm betting though that such effects - even when much smaller -
> occur during testing and some design is implemented that by
> good fortune fixes the flaw. The problem is that we are looking
> to explain things when each individual item is small and out
> at an asymptote. Sales guys then jump in and latch on to some
> theoretical, if unlikely, explanation instead of letting the
> company admit that they found it by accident and folks seem
> to like it :) But, being unable to explain it doesn't mean
> it is unexplicable - just sometimes difficult to explain.
>
> I'm willing to go through life allowing for things I don't
> understand - but am willing to learn about.

You 'have to know' your measurement was/is bogus, IMO, Bob's comments
are right on -- time to enter troubleshooting mode. Get a tripod for
the Ratshack meter. Get a good voltmeter. Figure out what's screwed
up-- it's not reactance in the zipcord or something similar -- it's
just a bad test or bad equipment. Just trying to help.