Effects of Inductance and Skin-effect in a speaker wire.

[E-Stat]

Perhaps a recap of the first sentence in this thread is called for...
"As far as sonic effects of inductance and Skin effect is concern..."

Don't stop there with the ellipsis. The last four words in the topic are:

in a speaker wire

.... or have we removed listening itself from the table?

Why would you do that?

rw

[markw]

Don't stop there with the ellipsis. The last three words in the topic are:

in a speaker wire



Why would you do that?

rw

I bow to your superior knowledge.

You've certainly proved to me that some people are so smart that the only people who can outsmart them are they themselves.

[jneutron]

Just reading through the thread but wouldn't any stored energy in the cables be insignificant or secondary to the back EMF from the drivers?? Or is this only an issue with the woofer as the midrange/tweeter would be an easier load?? I would think the drivers would be the real issue the amp has to deal with.

Hey John good luck on the house!!

If it were only a mono system, then it would be a horse of a different color. In a mono system, I'm not sure if shifting a vocal by 20 useconds would be distinguishable.

I was thinking about soundstage imaging only..Our ability to discern the direction of a sound source by the left to right ear delay. If any musical content (like a vocal) is time shifted 20 usec by some nefarious skin effect thingy brought on by a bass guitar (for example) on the left channel only, the human brain (mine too) would discern that time shift as a source shift if the leading and trailing transients shifted the same way, and I don't know what it sounds like if the shift is dependent on the amplitude or polarity of the bass current.

With a stereo pair, the actual response of the speakers, both phase and amplitude, is not in the least bit important with respect to localization of the image of the sounds. (this statement neglects ENTIRELY the science of the human ear, auditory canal, a huge amount of very good research...I believe Chuck (and JJ) has a very good grasp of that stuff if you really want to find out more about it. But all that will only confound what it is I am looking for..skin based time shifting of some component of the signal. My discussion is but a small and specific subset of all that other research...Ask Chuck how we can distinguish between a noise in front of us as opposed to behind us...)

I have experienced source shifting in headphones, one record in each ear, and varying the time relationship between the two...the image sounds like it is sweeping through the head. I can envision how confusing it would be if only a part of the musical content shifted that way.

Course..this all assumes a skin shift is even real..

Thanks...I'm chompin at the bit to start the attic. Cause that's where I'll put the computers..right now, I am cpu-less, and that is where the e/m analysis program I'm working on sits..waiting for more code.


Cheers, John

[E-Stat]

I'm chompin at the bit to start the attic. Cause that's where I'll put the computers..right now, I am cpu-less, and that is where the e/m analysis program I'm working on sits..waiting for more code.

When the wife and I built our home seven years ago, I tried to plan as best I could for various wiring needs. I have two dedicated AC lines in the basement intended for the main audio system. All rooms accomodate four telephone lines. Most rooms have a cable TV outlet. One thing, however, I didn't do was wire for CAT5. At first I thought that a problem, but now with fast and inexpensive WiFi, the situation has changed. I say all of this to suggest that you may want to place a wireless router in a more central area of the house to allow access virtually anywhere. It is handy indeed to be able to take my laptop to any room or outside on the deck so that I can spend far too much time on audio boards!

rw

[jneutron]

When the wife and I built our home seven years ago, I tried to plan as best I could for various wiring needs. I have two dedicated AC lines in the basement intended for the main audio system. All rooms accomodate four telephone lines. Most rooms have a cable TV outlet. One thing, however, I didn't do was wire for CAT5. At first I thought that a problem, but now with fast and inexpensive WiFi, the situation has changed. I say all of this to suggest that you may want to place a wireless router in a more central area of the house to allow access virtually anywhere. It is handy indeed to be able to take my laptop to any room or outside on the deck so that I can spend far too much time on audio boards!

rw

Thanks for the suggestion. I am concerned with security and wireless networks, though. At work, they are a pita for the it people.

When I built a house a long time ago, I went in before the sheetrock was placed, and took a lot of pictures of the stud locations, so that I could more easily add wires in the future should the need arise (which it did). I was quite proud of my ability to think ahead in this regard..


Film in the camera would have been nice, though...

Cheers, John

[E-Stat]

I am concerned with security and wireless networks, though.

Absolutely. I use WEP both at home and at work. (I work for a software developer) Configuring a good firewall and router security is a bit of a PITA, but once set, usually requires little maintenance.

Film in the camera would have been nice, though...

Naw, I've never done anything like that...

rw

[Tony_Montana]

If it were only a mono system, then it would be a horse of a different color. In a mono system, I'm not sure if shifting a vocal by 20 useconds would be distinguishable.

With a stereo pair, the actual response of the speakers, both phase and amplitude, is not in the least bit important with respect to localization of the image of the sounds.

Hey John

I agree with you that in mono, phase shift of signal (at least for 20 usecond) will not matter that much. But i don't understands yourstatment about the stereo pair.

Since for stereo pair, phase shift property of "stereo" signal is used to project imaging to side or even to the back of head (for example the simulated surround capability of two speakers used for TV), then wouldn't phase shift be a concern in stereo pair?

[mtrycraft]

I was thinking about soundstage imaging only..Our ability to discern the direction of a sound source by the left to right ear delay. If any musical content (like a vocal) is time shifted 20 usec by some nefarious skin effect thingy brought on by a bass guitar (for example) on the left channel only, the human brain (mine too) would discern that time shift as a source shift if the leading and trailing transients shifted the same way, and I don't know what it sounds like if the shift is dependent on the amplitude or polarity of the bass current.

But, that 20usec needs to be the difference between the two cables, in that example to cause the same shift. R.A.Grainer and the other referenced article could not come even close to those time periods, by several order of magnitudes.


I have experienced source shifting in headphones, one record in each ear, and varying the time relationship between the two...the image sounds like it is sweeping through the head. I can envision how confusing it would be if only a part of the musical content shifted that way.

Varying it by how much?

Course..this all assumes a skin shift is even real..

Why would it be not real? All the present day texts claim it real and calculate it to be real. The audibility of the magnitude is the question.
No such data is available.

[jneutron]

But, that 20usec needs to be the difference between the two cables, in that example to cause the same shift. R.A.Grainer and the other referenced article could not come even close to those time periods, by several order of magnitudes.

Yes, I agree, the diff has to be between cables..that is why I gave the example of the bass lines on one channel only, somehow causing a nefarious shift of the vocals on one channel only..

I have experienced source shifting in headphones, one record in each ear, and varying the time relationship between the two...the image sounds like it is sweeping through the head. I can envision how confusing it would be if only a part of the musical content shifted that way.

Varying it by how much?.

I don't know, but it varied from 100 milliseconds (obvious echo type) to zero. When I played a nightclub back in the late 70's, one of the effects I used was to play two identical songs at the same time, at equal levels. The phasing/flanging effect was neat, making a comb filter (inna gadda da vita style). But as the DJ, I had each turntable feeding one ear only, the perfect cancellation the dancers heard when shift=zero was when the image in my head was dead center. I could tell by the image location within my head, how the sound effect outside was going.

Course..this all assumes a skin shift is even real..

Why would it be not real? All the present day texts claim it real and calculate it to be real. The audibility of the magnitude is the question.
No such data is available.

My apologies..when I say skin shift, I am not talking about the group delay stuff, 250 nano type..that is unquestionably beyond human hearing. I am talking about a complex musical content waveform being capable of time shifting some transient information by AT LEAST 20 microseconds (my arbitrary, simplistic threshold for image shifting). 250 nano is a waste of time w/r to audibility, IMHO. I must confess that I've not been able to peruse any of your links yet, I'm concentrating on putting boxes into and out of my minivan as the movers come Sat...but I'd be surprised to see that anyone has even examined their test setups for accuracy issues I point out. (I also assume some of the links include testing, and not just math.) But the present day texts I've seen still treat skin effect as a simple sine analysis, using the frequency domain without regard to energy balance equations..If I am correct, they will have to re-write the textbooks for the inclusion of slew rate based skinning. (not asking much, huh?) I still discuss my stuff with the guys here, and nobody has been able to shoot it down yet..(doesn't mean I'm right either).

In all my research, I've not seen anybody concentrating on the capability of the load resistor with it's slew errors...a very confounding issue for high speed high current low impedance measurement accuracy, and the very first item I hit upon in my skin test endeavors. I will (once I'm back up) be applying a rigorous testing regime to my load and current viewing resistors, to make sure the I/V phase errors remain very low up to at least 1 to 2 Mhz. That way, I can assure myself that the errors at audio freq's are negligable.


Tony: ""then wouldn't phase shift be a concern in stereo pair?""

Yes, it is..but, I'm concentrating only on left to right difference related to a skin phenomena...overall phase shift of each speaker is way, way over my simplistic approach, and something more suited to a speaker type forum..

Cheers, John

[mtrycraft]

Thanks. Maybe you will come up with a new textbook

[mtrycraft]

Thank Mtry.

The references you provide seem to be alot of good reading. Do you know how can I get a copy of those reports....free be best ?

You know, I got so bugged down on details about inductance and skin effects of the cable that I forgot to take into consideration the effects of speaker and amplifier on the signal (as others have mentioned). That does bring this issue to whole new light as far as cable's effect on the system [as a whole] is concern.

S I guess the question now becomes...will be worth to fix few nanosecond/dB of signal shift/attenuation caused by cables, as compared to greater magnitude of phase-shift/attenuation caused by speaker/amplifier?

Back to the drawing board again

Yes, free is best but I don't know. AES is not that expensive, or a nearby University library with EE course?


I would worry about speakers first, today. nothing second, really. Considering the complexity of properly converting the electrical signal to acoustic properly, everything else is insignificant today. Radiation pattern uniformity, enery output uniformity with off axis performances, speaker compression, distortion, etc.

[Tony_Montana]

I live on university campus so I see if I can check out those AES papers. They probably got them on microfilms

[mtrycraft]

I live on university campus so I see if I can check out those AES papers. They probably got them on microfilms

Maybe, but I am not aware that any has been filmed I think they are only $10 for Journal papers.