connect 2 different wire gauge to pos and neg speaker terminal

Thank you, Kijanki. I was just about to post that numerous references can be found on the web indicating that the dielectric constant of Teflon is in the vicinity of 2.0, or even a bit more, not 1.0. Also, the 70-85% figure Geoff cited is of course at best an average or typical propagation velocity, and examples of audio cables having propagation velocities that are significantly slower and significantly faster are easily found.

Steve (Williewonka), the book you referenced looks like an excellent read! I note, btw, that the section your link goes to was authored by Bill Whitlock, of Jensen Transformers, who like Ralph Morrison is a noted authority on such matters. And I note that Mr. Morrison himself is referred to in Mr. Whitlock’s writeup.

Also, if I may be a bit presumptuous, let me extend kudos for your interest in gaining as thorough a technical understanding of such matters as possible, to complement what I know is your very extensive practical experience experimenting with various cable configurations.

Regards,
-- Al

kijanki
3,274 posts                                                                     08-24-2017 6:39pm

Dielectric constant of Teflon is about 2. Vacuum has dielectric constant of 1.

Yes, Teflon will slow down electromagnetic wave. Insulator will slow down electromagnetic wave by amount based on its ability to store energy - Permittivity. Dielectric constant is just relative Permittivity. This speed of electromagnetic wave thru typical insulated wire is about 60% of the speed of light in the vacuum. For typical cable it comes to about 5ns/m and it is exactly true for cat5 cable. There is no different electromagnetic wave for audio signals and other signals.

kijanki,

Can the type of dielectric used cause distortion of an analog signal as it travels through an interconnect? What frequencies, would you say, are affected the most?
Example PVC vs Teflon?

Tough question.... Can it be measured?

Jim

Geofkaitt, Yes, it is about 66%  = 5ns/m (I inverted it wrong).  Teflon is probably a little faster.  They also use foam Teflon to lower dielectric constant.  In addition wires can be in the hollow tubes since dielectric constant of the air is pretty much the same as vacuum (approx. 1)

Jea48, Dielectric can possibly cause distortion since it absorbs and releases energy.  Example of this is capacitor that is charged, discharged by shorting and then opened.  Voltage on the capacitor will start growing back from zero to many volts.  It is very pronounced in electrolytic capacitors.  It happens because dielectric stores and returns energy.  It is called Dielectric Absorption and is also related to Permittivity.  Returning voltage when signal has already different level can cause distortion.  Looking at the lines of audio cable I can say that price is proportional to dielectric used.  PVC, that you mentioned is pretty bad while Polypropylene is better, Teflon better yet and oversized tubes of foam Teflon are the best (Acoustic Zen Absolute IC).  How much of this is audible I don't know.  AZ Absolute sounded "cleaner" to me (more refined), but it can be placebo effect (I expected it).  Dielectric Constant also affects capacitance between wires. Capacitance of typical cable is around 25pF/ft while AZ Absolute IC is 6pF/ft.  Can capacitance of IC be a source of tiny distortion?
Al, what is your opinion on dielectric absorption in audio cables?  Can this be audible?

@kijanki,

Thank you for the response.
Jim

Thanks once more, Kijanki. Your post just above is excellent IMO, as usual.

As far as the audibility of dielectric absorption in audio cables is concerned, my reading of various technical and anecdotal references to that effect I've seen over the years suggests to me that it stands a good chance of being audibly significant in many applications. However I have never seen either an analysis or measured data that would provide a quantitative perspective on it, in the context of audio cables.

So FWIW my own "expectation bias" is in the direction of that effect being great enough in degree to be an audibly significant contributor to cable differences, in many systems. But as far as I am aware information doesn’t seem to be available that would provide insight that is more specific.

Best regards,
-- Al