Actually it is not hard to measure the thermal change and it increases as frequency decreases and can be as high as -30db third harmonic from a brief test I did.
I have too much to do at the moment to do a full scale test of that issue.
HoJo wasn't too bad, but did not directly answer this question:
Johnson, Howard. High Speed Signal Propagation, 3.7.6..step response...around page 197. The discussion centers around the actual IR loss while the skinning is occuring.
I didn't find much else that could be directly applied, as everybody tends to be interested in rms power loss, not instantaneous.
Sullivan has loads of stuff, but again, it's basically rms.
Whenever the resistance of a conductive channel is modulated by the signal itself, one must consider non-linear losses. Skin effect is by design, the modulation of the channel current density and utilization.
Cheers, jn
Some strange reason????
Face it...you are strange...that is reason enough..
Not diodes... perhaps noise, perhaps 3f harmonics..
But not diodes!!!
cheers, jn
Some strange reason????
Face it...you are strange...that is reason enough..
Not diodes... perhaps noise, perhaps 3f harmonics..
But not diodes!!!
cheers, jn
I will defer to the expert on strange!
Did-you mean distortion generated by heat in a 12AWG wire on a resistive load, at normal audio levels ? (The only thing i can think-of is the time my toaster takes to turn red ;-)
If it is acoustic distortion of the loudspeaker, i do not imagine how to measure thermal effects, in between all those non linearity mechanical distortions. Same thing if you make an electrical measure, because electromotive forces.
Take ten dynamic loudspeakers arrange them in a Wheatstone bridge with four on the top left and four on the bottom right. Apply a signal to the top and bottom and monitor the difference. The distortion is what is generated by the difference in level of the voltage across the transducers. Some of that is due to changes in voice coil resistance. Vary the frequency and watch how the harmonics change!
They will talk to each other if you're not careful. You mean series parallel in two legs (the 4) and one in each other leg? I suspect you get a horrible mess of hard to understand data.
Surprisingly not a mess! With common airspace lots more coupling than each inside their own fiberglass compartment, but strikingly common results, BUT only one quick proof of concept test. Idea is to see what the electrical contribution is to distortion. Lots of mechanical contribution! Which is why it is not a high interest item. But the electrical distortion seems to be real, just probably not significant. (Reserve the right to change that OPINION after more playing.)
I know you are gonna find it hard to believe but dynamic cone transducers produce distortion!
nothing hard about finding dynamic loudspeaker distortion info
http://www.klippel.de/know-how/introduction.html
Papers
hard to believe its the 1st ref Klippel's site in this thread
but then again it looks like several ran on about lack of cable electrical measurements despite my link to Nelson's paper on the 1st page of the thread too
http://www.klippel.de/know-how/introduction.html
Papers
hard to believe its the 1st ref Klippel's site in this thread
but then again it looks like several ran on about lack of cable electrical measurements despite my link to Nelson's paper on the 1st page of the thread too
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I guess you may have more consistent datas if you use 1000 identical loudspeakers in each branch of your Weston bridge, and if you measure them in the range of frequencies where the cones does not fractionnates, and if they are in an anechoic chamber ?
Don't forget loudspeakers have huge disparities and acts like microphones, too ;-)
That's all the pleasure to read this thread about cables, keeping loudspeakers in mind.
Oh, yes, to know that we don't have, again, to fear heat phenomenas in speaker's cables.
Is is marvelous to see how much complicated physical phenomenas occurs at both sides of this "non object" speaker cable.
Don't forget loudspeakers have huge disparities and acts like microphones, too ;-)
That's all the pleasure to read this thread about cables, keeping loudspeakers in mind.
Oh, yes. I had forgotten this study. I had read-it, but don't knew what some can do with it.
Oh, yes, to know that we don't have, again, to fear heat phenomenas in speaker's cables.
Is is marvelous to see how much complicated physical phenomenas occurs at both sides of this "non object" speaker cable.
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Oh. never thanked you for that link..thank you.
The paper doesn't touch at all on what I speak of. However, they do include the termination network required at the end of the low impedance cable to prevent amp oscillation. That's simply a consequence of the unloading of the speaker at hf..
Cheers, jn
Surprisingly not a mess! With common airspace lots more coupling than each inside their own fiberglass compartment, but strikingly common results, BUT only one quick proof of concept test. Idea is to see what the electrical contribution is to distortion. Lots of mechanical contribution! Which is why it is not a high interest item. But the electrical distortion seems to be real, just probably not significant. (Reserve the right to change that OPINION after more playing.)
I know you are gonna find it hard to believe but dynamic cone transducers produce distortion!
I hope less than the wires
I hope less than the wires
Scott,
WE just gotta disagree on everything. My OPINION is that dynamic cone loudspeakers have more distortion the any normal interconnecting cables!
(I know what you meant.)
ES
Too bad for most of us witch had spend more time and money on our enclosures than our cables !
Scott,
WE just gotta disagree on everything. My OPINION is that dynamic cone loudspeakers have more distortion the any normal interconnecting cables!
(I know what you meant.)
ES
bah... next thing y'all are going to say is power sources introduce distortion into the system... and that you can measure it... witchcraft if you ask me....
go on, this is interesting
back to popcorn
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I kindly ask you gods of maths why i have had good luck with THHN 12 Awg, 2 Conductor Wire Twisted Black/Red, for permanent installations. (churches, halls, etc.) One of the old farts at Altec Lansing showed me this many many years ago. I've always wondered why it worked so well.example:THHN 12 Awg. 2 Conductor Wire. Twisted Black/Red, 500' Spool
i use this now : http://www.monoprice.com/products/p...=1023901&p_id=2817&seq=1&format=2#description
Thanks
rev.
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It works well for several reasons: It's twisted so will be less sensitive to induced electromagnetic fields; it's relatively rigid and that plus the insulation materials it is made of minimizes triboelecric effects; it's a relatively heavy gauge conductor so will maintain generally good coupling between the amplifier and speaker even over longer runs; the insulation material prevents surface oxidation which deteriorates sound; the conductors are uncoated bare copper so do not suffer from the widely noted brightness and hardness that silver plated copper wire has; it is not multistranded so does not suffer the several audible ills that stranded wire suffers from that manifest themselves as a slight masking of detail and an overall dullness of sound when there is surface oxidation. Some claim that mechanical vibration induced interstrand conductivity changes deteriorate the audible performance of noninsulated multistrand wire.
It's not perfectly neutral though - a solid round conductor of this gauge has a slight audible downward spectral skewing at high frequencies that IMO starts to exhibit itself when using wire gauges heavier than about 18 AWG - but that may actually be a net benefit when coupled with otherwise bright sounding components or to smooth over the asperities of harsh sounding digital audio somewhat.
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