Favorite speaker wire?

[hifiZen]

Well thought out, if a little difficult to mount on a speaker cabinet due to the odd pattern of holes and recesses needed. It's manageable with a router and some plunge bits.

[planet10]

Originally posted by hifiZen
This is the post I was referring to:

A customer sent us some of those for his speaker... i hate them.

If i'm going to spend serious money on connectors, i'll get Eichmann.

dave

[hermanv]

Re the Cardas single knob post. While they seem to be an excellent electrical connector, I always seem to be one hand short of the number required to connect the wires. One hand to tighten the knob one hand to hold one of the two wires.

They are good for a connection that won' be disturbed, if you plan a lot of changes or experiments my advice is stay away.

I used to clean my banana plug equipped wires about every 3 months (because they needed it) now with the Cardas Rhodium over silver/copper lugs it's closer to a year.

I also love the Cardas contact cleaner, while the initial price is high, that little bottle lasts a long time.

Scottmoose: Yes this is a DIY forum, but people also look here for advice on what to buy.

I think I'm about done posting here, said what I wanted to say, people may or may not agree, that's fine by me

[Scottmoose]

Originally posted by hermanv
Scottmoose: Yes this is a DIY forum, but people also look here for advice on what to buy.

Precisely. Why do you think we keep banging on about system matching? To try to help people get the optimum (practical) match, that's why.

[jneutron]

Originally posted by hermanv
[B]Jneutron: Some cable advocates are pushing for 22 or 24 AWG wire, in this case the length for a given inductance is quite different.

Actually, the inductance of a parallel pair is determined by the ratio of the wire metal diameter to the outer insulation diameter. The scaling of the wire and insulation is of no consideration. In other words, if two wire pairs have the same insulation thickness percentage of the wire metal diameter, they will have the same inductance..(that log(a/b) term is the same)

Originally posted by hermanv
[B]
I agree however that 63 uH is not reasonable and only used that value to match the 0.08 Oms (also arbitrary). 10 milliOhm and 2.5 uH is more reasonable or likely.

Yah, those numbers are far more reasonable...

Cheers, John

[hermanv]

Originally posted by jneutron


Actually, the inductance of a parallel pair is determined by the ratio of the wire metal diameter to the outer insulation diameter. The scaling of the wire and insulation is of no consideration. In other words, if two wire pairs have the same insulation thickness percentage of the wire metal diameter, they will have the same inductance..(that log(a/b) term is the same)

Cheers, John

Due to manufacturing technique the smaller gauge wire will have a greater proportional insulation thickness and therefore a higher inductance.

[jneutron]

Originally posted by hermanv
Due to manufacturing technique the smaller gauge wire will have a greater proportional insulation thickness and therefore a higher inductance.

The thickness of the insulation is a result of selection of material, voltage withstanding, abrasion resistance, radiation resistance, coating method, number of layers, governing specification, application..ad nauseum....

Kapton, rubber, pvc, kynar, pvc, polyimide, tefzel, teflon....

Dipping, extrusion, wrapping, conformal coating.

Low voltage wire, high voltage wire..

NEC, IEC, custom specifications..

Mining, flight hardware, space, cryogenic...

A #10 awg teflon coated wire has a smaller proportion of insulation than a cat5e 24 guage conductor. A #24 polyimide coated magnet wire has a very small proportion of insulation...

If only it were just the wire diameter...

I'd love to plop the terman inductance equation on this website, something that everybody could use to find the inductance of any wire..I do not know how to do this...

Cheers, John

[hermanv]

The following inductance equation is a close approximation (John I did this using the symbol and size font, a painful way to insert an equation. There probably is a better way).

The inductance L of a short wire pair is approximately given, as inductance of parallel plates, by L=mo(l • ts) /w, where l is the length of the short wires, w is the width, mo is the permeability and ts is the separation distance between the short wires.

This does not allow for a different permeability for the insulator and any air between the wires. Also note that "short" is not defined.

[jneutron]

Tomorrow I'll post the terman equation.

Seems to me there's a "log" thingy in there somewhere...

I believe it is setup for permeability of 1, so it's pretty much what we'd be able to use..as opposed to one of those god forsaken "universal equations" that end up being universally useless..


(you think I know these things off the top of my head???...I'm not like sy....

Cheers, John

[jneutron]

Originally posted by hermanv
The following inductance equation is a close approximation (John I did this using the symbol and size font, a painful way to insert an equation. There probably is a better way).

The inductance L of a short wire pair is approximately given, as inductance of parallel plates, by L=mo(l • ts) /w, where l is the length of the short wires, w is the width, mo is the permeability and ts is the separation distance between the short wires.

This does not allow for a different permeability for the insulator and any air between the wires. Also note that "short" is not defined.

Yah, they do tend to insert useless words like "short" with no boundaries..I hate that also.

The parallel plate approximation assumes an easy reluctance path, but it isn't quite so easy with the round conductors.

The terman equation has 3 components...first, the variables and units..

length is given in inches
D is the wire spacing, center to center
d is the wire diameter
log is base 10
delta = .25 at zero frequency.
mu is relative permeability, =1

L (uH) = .01016*length*{2.303*log(2D/d)-(D/length) + (mu * delta)}


The first part ...2.303*log(2D/d).. is the portion which describes the dipole field around the round wires..note that as long as the relation between the wire spacing and the wire diameter is the same, this equation provides the same value. If you double the diameter and double the spacing, the fraction 2D/d is unchanged.

The second ...D/length...is a correction for field enhancement when the lengths are very small.. When using the full equation for binding posts for example, this term will get you into trouble very quickly. For typical wires we speak of, this term should be ignored...zero.

The third term ...mu * delta... is the inductance within the cylindrical conductors. At DC, mu is 1 and delta is .25. At infinite frequency, delta = 0. (note: for a hollow conductor like the outer braid of a coaxial cable, this term can be considered as zero. There is no magnetic field within a hollow conductor, therefore no inductance..)

I just use part 1 and 3, set delta = .25, and plop it into a spreadsheet. What pops out is simple graphs of inductance vs wire spacing..

Cheers, John