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OK I'm trying to understand this new to me term "Dielectric" if some one can give me a couple paragraphs of what this is and how it effects my (in this case) Speaker cables I would be grateful.I also have a question based on what little I do know.
in the following example
16ga OFC fine stranded wire
Wrapped with Teflon plumbers tape using a 1/4" overlap (resulting in
basically two full layers of tape)Does any type of insulation out side of the Teflon tape cause a problem with the Dielectric properties of the cable?
Would having an air gap between the Teflon tape and any other type of insulation be an improvement?
I'm just starting to try to understand some of these terms and methods with the goal of being able to DIY a couple of different Speaker cable ideas I have.
Any help (yes I know about the Home Depot extension cords)will be greatly appreciated.
Follow Ups:
A dielectric material is an insulator or conductor with high resistance, where there can be an electric field. For our purposes, an electric field is the spatial manifestation of a voltage difference, such as the instantaneous voltage associated with an audio signal at a place along the cable. Most folks are familiar with the image of iron filings sprinkled over a sheet of paper placed over a magnet: the filing arrange themselves along the lines of magnetic force. Well, there are similar lines of electric force that go from one conductor to another at a different voltage, but it is much more difficult to demonstrate them as the filings do for magnetic lines of force.The 'dielectric constant' of a material is a measure of how much energy the electric field stores within that material. The higher the number (which is relative to vacuum, a perfect dielectric), the greater the energy storage, and the more the lines of force will go through that material if a lower dielectric constant material is nearby.
Perfect dielectrics have the property that the 'dielectric constant' is really a constant and not a function of the recent history of the electric field within the material. All real dielectrics that are solid materials deviate from perfection in having some memory. The technical term for this is 'dielectric absorption,' and the most common phenomenon encountered by audio tinkerers is when filter capacitors appear to recover some of the voltage stored on them, even after the equipment is shut down and the capacitors discharged with a resistor (ouch!).
Many audiophiles prefer Tefon as wire insulation because it has one of the least levels of dielectric absorption of all the common plastic insulators. The same is true for insulators used in making capacitors, so Teflon capacitors are highly regarded (and very expensive!). I'm making a post hoc fallacy here, as I don't know of direct evidence that dielectric absorption is the root cause of audiophile preferences, but the circumstantial evidence seems strong.
Cotton is an interesting insulator for wires. It has a low dielectric constant because it contains a lot of air, and the fibers are all of different lengths, so it does not have strong acoustic resonances found in synthetic fibers. In my experience, it is as neutral-sounding as Teflon, and is superior for making up bulk where excessive amounts of Teflon tape would be required. However, the dyes used for colored cotton may affect its properties, and it is somewhat hygroscopic.
In your example above, the Teflon provides a little mechanical protection and vibration damping, and helps determine the dielectric properties of the cable. However, the material is soft and will not prevent shorts if the cable is subject to any handling whatever. Whatever material is used over the Teflon will have a lot of influence on the dielectric properties. If you are making speaker cables, I suggest getting some pure cotton batting from a fabric store (most is polyester or cotton blended with polyester, but you can find pure cotton), and cutting it into convenient strips. Wrap the wires with one or more layers of the batting, then use an outer wrap of Teflon tape to secure the batting.
Dielectric is a fancy word for "electrical insulation". Different materials have different insulating properties. Teflon is a very good insulator. Cotton is excellent. Air is considered the best. The main issue is the direct interaction between the conductor and the insulator, so I don't think an "over-insulator" over your teflon tape would have a noticable impact on the sound. To make things a little more difficult, many folks believe that different dielectric materials affect the sonic qualities of the conductor (in applications where there is direct contact between the conductor and dielectric). I personally have experienced this, so I am a beleiver. Teflon, while easy to use and find, creates a flatter and less real sound to my ears. Cotton, however, brings an almost eery realism to the sound. I admit that these results are based on solid core silver ICs, not stranded copper. If you are like most of us here in the asylum, experimentation is a big part of the fun of this obsession, uh.... I mean hobby. So go ahead and try.
Thanks that sure helps. My "problem" as far as experimenting is that my speaker cables have to be approx 20 foot long. So it can get very expensive buying and making something that I'm not happy with.If I were making interconnects for a couple of units that sit a foot apart Hey no problem I could justy 4-5 different ideas.
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