Dielectrics and such...??


Knowing a little about something can be dangerous! Having read about poor dielectric designs, static fields, EMI…etc., I don’t know if my idea of executing some shotgun runs of speaker cables is a good or bad idea….

I want to use double shotgun runs of Kimber 4tc per speaker. Rather than twist the runs together, I want to try keeping them separated at equal width throughout the runs. My thought is to “laminate” four equal lengths of the cables together with some type of clear tape (i.e.: separate and secure four lengths of cables by an equal and consistent width throughout the run – say one-inch - by “sandwiching” all four cable between heavy clear tape).

Question: will the tape itself hinder the dialectic properties of the cables (because I assume the tape is a poor dielectric)…??

What say you electrical engineer types?

Thank you.

_Ben
2chnlben

Showing 4 responses by kijanki

Al, that's perhaps why some manufacturers use foam Teflon (including my Acoustic Zen Absolute ICs) - not only to lower dielectric constant but to reduce absorption (introducing air). As for driving 1.5nF - I'll take your word, having limited experience.
Al, I didn't notice the link you provided. I agree that 22nH per foot would be extremely low and we can take it out of the equation. So what else is there (other than resistance, inductance or dielectric) to consider?
2chnlben , What is your objective? Dielectric properties of the tape (you could use Teflon tape) are secondary IMHO to fact that you defeat shielding of the cable achieved by twisting. Twisting two wires exposes them equaly to fields (noise) and since induced identical currents cancel it becomes very effective shielding. Output of your amp is most likely also an input especially at high frequencies.
Al, Yes part of the noise would be cancelled. Twisting just offers better cancellation.

Reduction of inductance might be more important than reduction in resistance since xover inductor in series with the woofer has most likely around 0.08ohm limiting DF to 100. Assuming he can cut inductance by 2 it will be 200nH per ft less, making two runs of 10' equal 4uH equivalent to 0.5ohm reactance reduction at 20kHz.