[Audio Empire]

On Tue, 19 Oct 2010 19:49:02 -0700, August Karlstrom wrote
(in article ):

On 2010-10-19 21:57, Audio Empire wrote:
On Tue, 19 Oct 2010 06:48:24 -0700, August Karlstrom wrote
That's great. Then we have real expertise here. What I'm/we're trying to
find out here is how thin a wire can be before it will make an audible
difference in the best possible system - a table like the one in the
Wikipedia article but for critical applications.

I don't understand the purpose of your query, I guess.
[...]

If I can use an even thinner and cheaper cable with the same excellent
result why shouldn't I choose that one? I find this optimization problem
theoretically interesting.


/August

OK, as an intellectual exercise, maybe, but practically speaking, we're
talking pennies of price difference between thinner and thicker. I feel that
a little overkill is the lesser of two evils, I guess.

[isw]

In article ,
Audio Empire wrote:

On Tue, 19 Oct 2010 06:47:43 -0700, isw wrote
(in article ):

If you're being *that* picky, you might want to take skin effect into
account, and use nothing larger than about #18 AWG, paralleling to get
the resistance down to what you think you need.

Isaac


"Skin effect" at audio frequencies? You're joking, right?

Do the numbers. The skin depth of "ordinary" copper wire is about equal
to the radius of #18 wire at 20 kHz. Using larger diameter wire will
give you greater resistive losses at high than at low frequencies; using
smaller will give you more-or-less equal losses over the audio range.

To be sure, the differences are totally inconsequential, but so are many
other things that some people insist on spending a lot of money on in
their audio systems. If you're going to be picking nits, you should not
ignore any...

Isaac

[Audio Empire]

On Tue, 19 Oct 2010 18:57:30 -0700, Trevor Wilson wrote
(in article ):

Audio Empire wrote:
On Tue, 19 Oct 2010 06:47:43 -0700, isw wrote
(in article ):

If you're being *that* picky, you might want to take skin effect into
account, and use nothing larger than about #18 AWG, paralleling to
get the resistance down to what you think you need.

Isaac


"Skin effect" at audio frequencies? You're joking, right?

**The skin effect occurs at all frequencies above DC. It is one reason why
power utilities are moving to DC transmission of power. That said, for all
practical purposes, in the vast majority of normal sound systems, skin
effect plays no part. BTW: Skin depth at 20kHz is approximately 0.5mm.




You remind me of a guy I used to know who was heavy into DIY audio. He used
to build all his own equipment, both tubed and solid-state. He would even buy
vintage pieces like Harman-Kardon Citation I preamps and Dynaco PAS-3s and
Leak and Quad and McIntosh and Marantz stuff and replace all the old paper
and ceramic caps with modern, polypropylene and Polystyrene units and he'd
replace all the old carbon composite resistors with modern metal film units.
All laudable tasks, indeed. But whether he was rebuilding an old classic or
building something from scratch, he insisted on using Mil-Spec ICs and
transistors and replacing 10% resistors and capacitors with precision, 1%
resistors. I and others tried to tell him that these precision parts were
overkill because nothing in these circuits was that critical. In fact, the
vintage stuff was only designed to "slide-rule" accuracy, and then rounded up
or back to the nearest standard component value. For instance, the maths
might give the designer a value of 45,500 Ohms for a certain resistor in the
circuit. Well, there is no standard 45,500 Ohm resistor, so the designer will
specify 47K because that's a standard value. Even the modern stuff, designed
with digital calculators and computers, uses parts rounded to the nearest
standard value. But he insisted on a 1% 47K Ohm resistor instead of a 10% 47K
Ohm resistor. It made no difference. 10% tolerance parts or 1% tolerance, it
all sounded the same. Now an RIAA preamp might have had a more accurate curve
using precision parts, but not precision to standard values, but rather
precision to the RIAA turnover and rolloff. This guy couldn't see it. I
guess using precision parts made him feel better about his creations, because
you certainly couldn't hear the difference, or even measure it.

If being hung-up on the minutia of speaker cable makes you feel better about
your system, then go for it, but when discussing these matters with people
less technically proficient than you are, you merely muddy the waters for
them. By adding ifs, thens, and buts that simply have little or no meaning to
the guy who just wants an adequate pair of 3-5 meter speaker cables for a
domestic (nominally) 8 -Ohm speaker system, you just confuse them.

[Sebastian Kaliszewski]

August Karlstrom wrote:
On 2010-10-20 01:06, Trevor Wilson wrote:
**Neither you nor I know if the inductance is relevant in teh system, since
we do not know the impedance characteristics of the speaker system. I
readily admit that it is highly likely that, given a 4 Metre cable run,
almost any cable will work, it is appropriate to point out that speaker
impedance should be determined before a recommendation can be given.

In my case I use a pair of Amphion Helium II.

"its plot of impedance magnitude and electrical phase angle reveals the
speaker to be very easy to drive, the impedance remaining above 8 ohms
for almost the entire audioband" -- John Atkinson at Stereophile

http://www.stereophile.com/budgetcom...on/index4.html

This is 7ohm load overall minimum and nearly 8ohm at 20KHz. This is
benign load, any cable will do for significant (50m!) lengths.

rgds
\SK
--
"Never underestimate the power of human stupidity" -- L. Lang
--
http://www.tajga.org -- (some photos from my travels)

[Chuckster]

"Never underestimate the power of human stupidity" -- L. Lang

I personally drive two pair of 'difficult' speakers: Carver Amazing
Silver MKll's and Infinity WTLC's, and have done a fair bit of
research. Given what's out there, I put my trust in one of the giants
of audio - McIntosh's Roger Russell. This can be found online, and I
consider it the 'bible' of speaker wire info - it has served myself
and my friends well:

http://www.roger-russell.com/wire/wire.htm

You simply can't go wrong with this information, and it's easy to
understand and apply.

Chuckster

[Trevor Wilson[_3_]]

"August Karlstrom" wrote in message
...
On 2010-10-20 01:06, Trevor Wilson wrote:
**Neither you nor I know if the inductance is relevant in teh system,
since
we do not know the impedance characteristics of the speaker system. I
readily admit that it is highly likely that, given a 4 Metre cable run,
almost any cable will work, it is appropriate to point out that speaker
impedance should be determined before a recommendation can be given.

In my case I use a pair of Amphion Helium II.

"its plot of impedance magnitude and electrical phase angle reveals the
speaker to be very easy to drive, the impedance remaining above 8 ohms
for almost the entire audioband" -- John Atkinson at Stereophile

http://www.stereophile.com/budgetcom...on/index4.html


**With such a benign load, you are not likely to experience any problems
with almost any sensible cable over a 4 Metre length.


--
Trevor Wilson
www.rageaudio.com.au

[Audio Empire]

On Wed, 20 Oct 2010 05:00:29 -0700, isw wrote
(in article ):

In article ,
Audio Empire wrote:

On Tue, 19 Oct 2010 06:47:43 -0700, isw wrote
(in article ):

If you're being *that* picky, you might want to take skin effect into
account, and use nothing larger than about #18 AWG, paralleling to get
the resistance down to what you think you need.

Isaac


"Skin effect" at audio frequencies? You're joking, right?

Do the numbers. The skin depth of "ordinary" copper wire is about equal
to the radius of #18 wire at 20 kHz. Using larger diameter wire will
give you greater resistive losses at high than at low frequencies; using
smaller will give you more-or-less equal losses over the audio range.

To be sure, the differences are totally inconsequential, but so are many
other things that some people insist on spending a lot of money on in
their audio systems. If you're going to be picking nits, you should not
ignore any...

Isaac


"To be sure, the differences are totally inconsequential". BTW, I probably
(due to my cable lab experience) know more about skin effect than anyone
here, my incredulity was prompted by the very idea that someone would
actually mention skin effect in the context of a speaker wire discussion. You
might as well bring-up the Miller effect and it's influence on amplifier
performance. It too is totally irrelevant to the user.

[isw]

In article ,
Audio Empire wrote:

On Wed, 20 Oct 2010 05:00:29 -0700, isw wrote
(in article ):

In article ,
Audio Empire wrote:

On Tue, 19 Oct 2010 06:47:43 -0700, isw wrote
(in article ):

If you're being *that* picky, you might want to take skin effect into
account, and use nothing larger than about #18 AWG, paralleling to get
the resistance down to what you think you need.

Isaac


"Skin effect" at audio frequencies? You're joking, right?

Do the numbers. The skin depth of "ordinary" copper wire is about equal
to the radius of #18 wire at 20 kHz. Using larger diameter wire will
give you greater resistive losses at high than at low frequencies; using
smaller will give you more-or-less equal losses over the audio range.

To be sure, the differences are totally inconsequential, but so are many
other things that some people insist on spending a lot of money on in
their audio systems. If you're going to be picking nits, you should not
ignore any...

Isaac


"To be sure, the differences are totally inconsequential". BTW, I probably
(due to my cable lab experience) know more about skin effect than anyone
here, my incredulity was prompted by the very idea that someone would
actually mention skin effect in the context of a speaker wire discussion. You
might as well bring-up the Miller effect and it's influence on amplifier
performance. It too is totally irrelevant to the user.

But not to the designer, while skin effect is inconsequential to both
camps *in the context of home audio systems*. As are a lot of other
characteristics that get thrown about in r.a.h-e.

Interestingly, the electrical power guys have to take skin effect into
account too, if their busbars get big enough; it begins to matter at
about 4 inches at 60 Hz, AFAIR.

Do you mean cable lab experience as in "CableLabs" in Boulder? I've had
some interaction with them...

Isaac

[August Karlstrom]

On 2010-10-20 22:15, Trevor Wilson wrote:
"August wrote in message
In my case I use a pair of Amphion Helium II.

"its plot of impedance magnitude and electrical phase angle reveals the
speaker to be very easy to drive, the impedance remaining above 8 ohms
for almost the entire audioband" -- John Atkinson at Stereophile

http://www.stereophile.com/budgetcom...on/index4.html


**With such a benign load, you are not likely to experience any problems
with almost any sensible cable over a 4 Metre length.

Yes, and this is most likely true even if I had a speaker with minimum
impedance of only four ohms - even a wire as thin as 2x0.75 mm^2 would do.


/August

[Sebastian Kaliszewski]

Trevor Wilson wrote:
"August Karlstrom" wrote in message
...
On 2010-10-20 01:06, Trevor Wilson wrote:
**Neither you nor I know if the inductance is relevant in teh system,
since
we do not know the impedance characteristics of the speaker system. I
readily admit that it is highly likely that, given a 4 Metre cable run,
almost any cable will work, it is appropriate to point out that speaker
impedance should be determined before a recommendation can be given.
In my case I use a pair of Amphion Helium II.

"its plot of impedance magnitude and electrical phase angle reveals the
speaker to be very easy to drive, the impedance remaining above 8 ohms
for almost the entire audioband" -- John Atkinson at Stereophile

http://www.stereophile.com/budgetcom...on/index4.html


**With such a benign load, you are not likely to experience any problems
with almost any sensible cable over a 4 Metre length.

You could substitute 40 for 4 and the statement will be true as well.

rgds
\SK
--
"Never underestimate the power of human stupidity" -- L. Lang
--
http://www.tajga.org -- (some photos from my travels)

[Audio Empire]

On Thu, 21 Oct 2010 07:18:13 -0700, isw wrote
(in article ):

In article ,
Audio Empire wrote:

On Wed, 20 Oct 2010 05:00:29 -0700, isw wrote
(in article ):

In article ,
Audio Empire wrote:

On Tue, 19 Oct 2010 06:47:43 -0700, isw wrote
(in article ):

If you're being *that* picky, you might want to take skin effect into
account, and use nothing larger than about #18 AWG, paralleling to get
the resistance down to what you think you need.

Isaac


"Skin effect" at audio frequencies? You're joking, right?

Do the numbers. The skin depth of "ordinary" copper wire is about equal
to the radius of #18 wire at 20 kHz. Using larger diameter wire will
give you greater resistive losses at high than at low frequencies; using
smaller will give you more-or-less equal losses over the audio range.

To be sure, the differences are totally inconsequential, but so are many
other things that some people insist on spending a lot of money on in
their audio systems. If you're going to be picking nits, you should not
ignore any...

Isaac


"To be sure, the differences are totally inconsequential". BTW, I probably
(due to my cable lab experience) know more about skin effect than anyone
here, my incredulity was prompted by the very idea that someone would
actually mention skin effect in the context of a speaker wire discussion.
You
might as well bring-up the Miller effect and it's influence on amplifier
performance. It too is totally irrelevant to the user.

But not to the designer,

Sigh! Of course Miller effect is not irrelevant to a designer, that's why I
said "to the user". But it is something that is not only inconsequential to
an amplifier's end user (the amp either HAS the bandwidth required, or the
input capacitance is so high that it doesn't), it's also beyond his control.
The same with skin effect of speaker cable. It's not only inconsequential for
the user, but beyond his control as well. Must we be so pedantic?

while skin effect is inconsequential to both
camps *in the context of home audio systems*. As are a lot of other
characteristics that get thrown about in r.a.h-e.

It's called obfuscation and whether done maliciously or just to "show off",
these irrelevancies don't help people like the OP who ask for help here at
all.

Interestingly, the electrical power guys have to take skin effect into
account too, if their busbars get big enough; it begins to matter at
about 4 inches at 60 Hz, AFAIR.

Do you mean cable lab experience as in "CableLabs" in Boulder? I've had
some interaction with them...

No, I mean like the Cable Laboratory at Lockheed Missiles and Space Company,
Inc. Where I spent three years doing everything to wire and cable and
connectors that it is possible to do. We evaluated wire and cable types for
bandwidth, skin effect, insulation integrity, capacitance, inductance,
impedance at frequencies from DC to daylight. We also tested cable in a
vacuum, cable (and connectors) in a pure oxygen environment, Cable and
connectors under high acceleration, high vibration, high temperature, low
temperature etc. We tested connector contact resistance (where I learned
about Stabilant (Tweek)), connector mating frequency, and reliability, pin
contact area, hermetic integrity, etc., etc, etc., ad nauseum.