Ok, how bad really are magnetic materials in binding posts?

[audiotemp]

mass that was magnetic, not mass as a property of magnetism.

Hey, now...electromagnetic "mass" is a real thing. Moving charges have momentum (and thus "mass") that is associated entirely with the EM fields that they generate. But this is not what was meant, obviously.

Looking forward now to finding me some no-moving-charges interconnect cables...

 

[Nat]

Do tell! I assume you don't mean reluctance or the time it takes fields to establish themselves - those concepts are somewhat familiar to me, but as I read your post, it seems you refer to something else.

 

[audiotemp]

Do tell! I assume you don't mean reluctance or the time it takes fields to establish themselves - those concepts are somewhat familiar to me, but as I read your post, it seems you refer to something else.

I think the fluid analogy is that dragging something through fluid makes it feel "heavy." "Fluid" here originally being the aether but now just EM effects in vacuum.

See Feynman Lectures Vol. II Ch. 28 for an interesting discussion. Also there's a Wikipedia article but I think the FL is more coherent.

 

[Nat]

Darn - citing Feynman makes it much harder to be confident in saying what seems intuitive (at least in the non quantum world), that having momentum isn't identical with having mass. But I am fairly comfortable arguing that audio wavelengths are unlikely to infringe on the mass/velocity relationship at the heart of quantum theory.
Perhaps presumptuous might be more accurate than comfortable...

 

[Mr Boochie]

Momentum isn't identical with having mass.

It isn't. Mass needs velocity to have momentum.

 

[Nat]

I'm aware of that, having taught high school physics for years. But I am not a physicist, so I was curious. I assume it related to the relativity of mass and velocity. Though I don't think magnetic fields propogate themselves at very near the speed of light, so I suspect it isn't particularly relevant to the original issue. But I could be wrong.

 

[Mr Boochie]

I'm aware of that, having taught high school physics for years. But I am not a physicist, so I was curious. I assume it related to the relativity of mass and velocity. Though I don't think magnetic fields propogate themselves at very near the speed of light, so I suspect it isn't particularly relevant to the original issue. But I could be wrong.

As far as I know, magnetic fields (as well as electric fields) propagate at the speed of light (*). Good Old Maxwell (and his silver hammer ) figured this one out.


* Speed of light

 

[toddalin]

Magnetic materials in binding posts can be VERY DETREMENTAL if they are allowed to come loose and are attracted to the magnet denting a valuable diaphragm while doing so!

Be aware that this goes beyond the binding posts and the spade lugs are also ferrous and the cases of "vampire bites" in JBL compression driver diaphragms is indeed numerous. All you have to do is let go of the wire when the lug is in proximity and

 

[audiotemp]

As far as I know, magnetic fields (as well as electric fields) propagate at the speed of light (*).

An EM field can be divided into two parts, longitudinal and transverse, also referred to as curl-free and divergence-free parts. This decomposition is due to Helmholz.

The transverse part of the field propagates at the speed of light. The longitudinal part changes over time as the source charges move around but doesn't propagate, per se. Uniform motion of a charge gives a longitudinal field that would move at whatever speed the charge is moving.

 

[Mr Boochie]

An EM field can be divided into two parts, longitudinal and transverse, also referred to as curl-free and divergence-free parts. This decomposition is due to Helmholz.

The transverse part of the field propagates at the speed of light. The longitudinal part changes over time as the source charges move around but doesn't propagate, per se. Uniform motion of a charge gives a longitudinal field that would move at whatever speed the charge is moving.

More importantly, EM waves travel at the speed of light in a vacuum. Any medium the wave travels through may interact and slow its velocity.

 

[Nat]

More importantly, EM waves travel at the speed of light in a vacuum. Any medium the wave travels through may interact and slow its velocity.

I was, of course, assuming a physical speaker with actual materials so everything would be slowed down.

 

[Ronnie T]

I use 99.999% Pure Silver speaker wire on a 4 way active system.

Pure Platinum wire for preamp signal path and pure silver for everything else.

You Can hear the difference.

Silver speaker wire...

I bet your speakers have copper wires inside and the power coming through yours walls is through copper and the wires in your amp are copper. I've never liked silver makes things toooo bright.

 

[Mr Boochie]

I bet your.soeakers have copper wires.

Are there any current commercially available speakers with silver voice-coil wires?

Thanks!

 

[opnly bafld]

Are there any current commercially available speakers with silver voice-coil wires?

Thanks!

Yes

 

[Mr Boochie]

Yes

They must be quite expensive.

 

[loudnoises]

They must be quite expensive.

Same labor involved, really just a material cost increase. I suppose that could be more than just copper vs silver. Lots of potential for markup in the end of course.

 

[Mr Boochie]

Same labor involved, really just a material cost increase. I suppose that could be more than just copper vs silver. Lots of potential for markup in the end of course.

That would seem to be a lot of silver.

Is there really that much difference in sound between a copper-wound VC and a silver one? I guess that is the eternal question about metals.

 

[Nat]

I believe Lowthers use silver voice coil wire. Certainly less resistance, and when Lowther started, efficiency really mattered. I forget whether copper is denser than silver - weight would be significant.
And yes, Lowthers are not cheap. But for many, they are worth it. I love my PM 6s in Radio People of Hong Kong back horns. But I got them at a church sale for twenty bucks. I had no idea what was in the cabinets, but I knew it had to be interesting. Unfortunately, I didn't realize how valuable the MCM angled legs were, and probably tossed them.

 

[Mr Boochie]

I believe Lowthers use silver voice coil wire. Certainly less resistance, and when Lowther started, efficiency really mattered. I forget whether copper is denser than silver - weight would be significant.
And yes, Lowthers are not cheap. But for many, they are worth it. I love my PM 6s in Radio People of Hong Kong back horns. But I got them at a church sale for twenty bucks. I had no idea what was in the cabinets, but I knew it had to be interesting. Unfortunately, I didn't realize how valuable the MCM angled legs were, and probably tossed them.

Those are so groovy in retro-1960s floor speakers.

 

[Nat]

I sort of agree, but I am appalled by the prices asked, especially for ones that were on JBLs and Altecs. They were dime a dozen standard parts in the 50s and early 60s, and James B Lansing didn't actually make any of them himself...